City of St. Peters, MO Residential Code for One- and Two-Family Dwellings

[R.O. 2007 § 504.040; Ord. No. 4626 §§ 1—2, 9-14-2006; Ord. No. 5305 §§ 1—2, 12-17-2009; Ord. No. 5543 §§ 1—2 (Exh. A(504.040)), 2-10-2011; Ord. No. 5603 § 1, 6-23-2011; Ord. No. 6958, 5-10-2018]

The Code adopted in Section 504.010 is amended as follows:

101.1 Title. These provisions shall be known as the Residential Code for One- and Two-Family Dwelling of the City of St. Peters, and shall be cited as such and will be referred to herein as "this code."

101.2.1 Application Of Prior Codes. At the discretion of the City Administrator of the City of St. Peters, contractors may be allowed to complete residential construction under prior building codes, if the City should adopt new code(s) during active construction of the subdivision.

102.5.1 Amend Appendices. Amend Appendices adopted under Section 504.010.

Appendix A. Sizing and Capacities of Gas Piping (Refer to Chapter 516 of the Municipal Code of the City of St. Peters).

Appendix B. Sizing of Venting Systems Serving Appliances Equipped with Draft Hoods, Category I Appliances, and Appliances Listed for Use with Type B Vents (Refer to Chapter 516 of the Municipal Code of the City of St. Peters).

Appendix C. Exit Terminals of Mechanical Draft and Direct-Vent Venting Systems (Refer to Chapter 516 of the Municipal Code of the City of St. Peters).

Appendix D. Recommended Procedure for Safety Inspection of an Existing Appliance Installation (Refer to Chapter 516 of the Municipal Code of the City of St. Peters).

Appendix E. Manufactured Housing Used as Dwellings.

AE101.1 General. Factory-built structures, modular units or closed prefabricated assemblies shall not be acceptable unless they are built within the jurisdiction of the City of St. Peters and are subject to inspection by the Code Official, with the exception of a manufactured home, modular unit, or closed prefabricated assemblies used as a single dwelling unit, and installed per Section 405.170, "R-M" Mobile/Modular Home Residential District. These provisions shall be applicable only to the above described manufactured home, modular unit, or closed prefabricated assemblies used as a single dwelling unit in the "R-M" Mobile/Modular Home Residential District:
1.	Construction, alteration and repair of any foundation system, which is necessary to provide for the installation of a manufactured home unit.
2.	Construction, installation, addition, alteration, repair or maintenance of the building service equipment which is necessary for connecting manufactured homes to water, fuel, or power supplies and sewage systems.
3.	Alterations, additions or repairs to existing manufactured home. The construction, alteration, moving, demolition, repair and use of accessory buildings and structures and their building service equipment shall comply with the requirement of the codes adopted by this jurisdiction.
These provisions shall not be applicable to the design and construction of manufactured homes and shall not be deemed to authorize either modification or additions to manufactured homes where otherwise prohibited.
Exception: New and replacement manufactured homes to be located in flood hazard areas are subject to Chapter 410, Floodplain Management of the Municipal Code of the City of St. Peters.
AE304.1 Permit Fees. (Refer to Attachment 1, Title V, Appendix A of the Municipal Code of the City of St. Peters.)
AE304.2 — Delete.
AE304.3 — Delete.
AE304.3.1 — Delete.
AE304.3.2 — Delete.
AE304.3.2.1 — Delete.
AE304.3.2.2 — Delete.
AE304.3.3 — Delete.
AE304.3.3.1 — Delete.
AE304.3.3.2 — Delete.
AE304.3.3.3 — Delete.

Appendix F. — Delete.

10.

Appendix G. — (No Changes).

11.

Appendix H. — Delete.

12.

Appendix I. — Delete.

13.

Appendix J. — Delete.

14.

Appendix K. — (No Changes).

15.

Appendix L. — Delete.

16.

Appendix M. — (No Changes).

17.

Appendix N. — (No Changes).

18.

Appendix O. — Delete.

19.

Appendix P. — (No Changes).

20.

Appendix Q. — Delete.

21.

Appendix R. — Delete.

22.

Appendix S. — Delete.

23.

Appendix T. — Delete.

24.

Appendix U. — Delete.

25.

R105.2 Work Exempt From Permit. Permits shall not be required for the following. Exemption from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction.

Building:
1.	One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed one hundred twenty (120) square feet (11.15 m²).
2.	Fences not over six (6) feet (1,829 mm) high.
3.	Retaining walls that are not over four (4) feet (1,219 mm) in height measured from the lowest adjacent grade to top of the wall, unless supporting a surcharge or impounding Class I, II or IIIA liquids.
4.	Water tanks supported directly upon grade if the capacity does not exceed five thousand (5,000) gallons (18,927 L) and the ratio of height to diameter or width does not exceed two to one (2:1).
5.	Sidewalks, patio and driveways except as required under Chapter 545, Section 545.020.
6.	Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work.
7.	Prefabricated swimming pools that are less than twenty-four (24) inches (610 mm) deep.
8.	Swings and other playground equipment.
9.	Window awnings support by an exterior wall which do not project more than fifty-four (54) inches (372 mm) from the exterior wall and do not require additional support.
Electrical:
1.	Listed cord-and-plug connected temporary decorative lighting.
2.	Reinstallation of attachment plug receptacles but not the outlets thereof.
3.	Replacement of branch circuit overcurrent devices of the required capacity in the same location.
4.	Electrical wiring, devices, appliances, apparatus or equipment operating at less than twenty-five (25) volts and not capable of supplying more than fifty (50) watts of energy.
5.	Minor repair work, including the replacement of lamps or the connection of approved portable electrical equipment to approved permanently installed receptacles.
Gas:
1.	Portable heating, cooking or clothes drying appliances.
2.	Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.
3.	Portable-fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power grid.
Mechanical:
1.	Portable heating appliances.
2.	Portable ventilation appliances.
3.	Portable cooling units.
4.	Steam, hot- or chilled-water piping within any heating or cooling equipment regulated by this code.
5.	Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.
6.	Portable evaporative coolers.
7.	Self-contained refrigeration systems containing ten (10) pounds (4.54 kg) or less of refrigerant or that are actuated by motors of one (1) horsepower (746 W) or less.
8.	Portable-fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power grid.
Plumbing:
1.	The stopping of leaks in drains, water, soil, waste or vent pipe; provided, however, that if any concealed trap, drainpipe, water, soil, waste or vent pipe becomes defective and it becomes necessary to remove and replace the same with new material, such work shall be considered as new work and a permit shall be obtained and inspection made as provided in this code.
2.	The clearing of stoppages or the repairing of leaks in pipes, valves or fixtures, and the removal and reinstallation of water closets, provided such repairs do not involve or require the replacement or rearrangement of valves, pipes or fixtures.

26.

R105.10 Integrated Permits. The Code Official may issue integrated building, plumbing, mechanical, electrical, etc., permits on a single permit application.

27.

R106.1.1.1 Sprinkler Verification. All applications for permit for one- and two-family dwellings shall include a written verification by the builder affirming that a fire sprinkler system was offered to the purchaser prior to entering into the purchase contract in conformance with Section R325.1 of this code. If there is no purchaser at the time of the permit application submittal, then said verification shall be made as soon as there is a purchaser and prior to the issuance of a certificate of occupancy for the new residence.

28.

R106.3.1 Approval Of Construction Documents. Where the Code Official issues a permit, the construction documents shall be approved, in writing, or by a stamp that states "REVIEWED FOR CODE COMPLIANCE." One (1) set of construction documents so reviewed shall be retained by the Code Official. The other set may be kept at the site of work or made available at the time of inspection and shall be open to inspection by the Code Official or a duly authorized representative.

29.

R108.2 Fee Schedule. (See Appendix A of this Title).

30.

R108.2.1 Amount Due Or Refunds. The Code Official shall authorize the refunding of money. The collection of fees due to the City and the refunding of money shall be as follows:

Refund the full amount of any fee paid hereunder which was erroneously paid or collected.

Refund ninety percent (90%) or collect ten percent (10%) of the permit fee when no work has been done on the site and application required a plan review to process a permit.

Refund eighty percent (80%) or collect twenty percent (20%) of the permit fee when no work has been done on the site and application required a plan review to process a permit.

No refund if permit has been voided; if work has been stopped; or if any work has been done at the site.

The Code Official shall not authorize the refunding of any fee paid, except upon written application filed by the original permittee not later than one hundred eighty (180) days after the date of fee payment.

31.

R108.6 Work Commencing Before Permit Issuance. Any person who commences work requiring a permit on a building, structure, electrical, gas, mechanical or plumbing system before obtaining the necessary permits shall be subject to a fee as set out in Appendix A of this Title. A fee may be assessed for each additional inspection that shall be in addition to the required permit fees.

Exception: Stakeouts and other necessary planning procedures.

32.

R109.5 Supplemental Inspection. In addition to the required inspection heretofore specified, the Code Official may make other inspections, which in his/her judgment is reasonably necessary due to unusual construction or circumstances. The Code Official shall have the authority to inspect any construction work in order to ascertain whether compliance with the Building Code is being met and in order that he/she may properly enforce the rules promulgated by this code. These inspections may include but are not limited to examinations to determine whether zoning requirements are being met, and may include all other phases of building construction. A fee as set out in Appendix A of this Title may be assessed for each additional inspection.

33.

R109.6 Extra Inspection. If by judgment of the Code Official an inspection requested is not ready or accessible for inspection, or in the judgment of the Code Official the applicant has caused the City extra inspections other than typically required, a fee as set out in Appendix A of this Title may be assessed for each additional inspection or re-inspection.

34.

R110.1 Use And Occupancy. A building or structure shall not be used or occupied, and a change in the existing use or occupancy classification of a building or structure or portion thereof shall not be made until the building official has issued a certificate of occupancy therefor as provided herein. Issuance of a certificate of occupancy shall not be construed as an approval of a violation of the provisions of this code or of other ordinances of the jurisdiction. Certificates presuming to give authority to violate or cancel the provisions of this code or other ordinances of the jurisdiction shall not be valid.

[Ord. No. 7490, 8-26-2021[1]]

Exceptions:

1. Work exempt from permits under Section R105.2.

2. Accessory building or structures.

[1]

Editor's Note: Pursuant to this ordinance, former Subsection (A)(34) through (147) were renumbered as Subsection (A)(39) through (152).

35.

R110.1.1 Use And Occupancy — Non- Owner-Occupied Dwelling Units. A dwelling unit shall not be occupied upon a change in occupancy thereof, nor shall any owner or agent thereof permit, allow, or cause any dwelling unit to be occupied upon a change in occupancy thereof, until the building official has issued a reoccupancy permit therefor as provided herein. A reoccupancy permit shall be required on each change of occupancy of a dwelling unit.

[Ord. No. 7490, 8-26-2021]

36.

R110.1.2 Applications And Issuance Of Reoccupancy Permit.

[Ord. No. 7490, 8-26-2021]

R110.1.2.1 Applications.
Prior to the occupancy of a dwelling unit upon a change in occupancy thereof, the owner of such dwelling unit shall make written application to the building official for a reoccupancy permit on a form to be furnished by the City for that purpose. Such application shall include such information as necessary to administer and enforce the provisions of, and to ensure compliance with, the provisions of Section 110.1.2.2.1 of this code.
R110.1.2.2 Action on Application.
The building official shall examine or cause to be examined applications for reoccupancy permits and amendments thereto, and shall inspect or cause to be inspected each dwelling unit to be covered by the reoccupancy permit and all common areas thereto, if any, within a reasonable time after filing, before a reoccupancy permit is issued.
R110.1.2.2.1 Reoccupancy Inspections.
The building official is authorized to and may make reoccupancy inspections of the dwelling unit to be covered by the reoccupancy permit and all common areas thereto, if any, upon a change in occupancy thereof. Such reoccupancy inspections shall be for the purpose of determining whether such dwelling unit and all common areas thereto, if any, comply with the provisions of the City of St. Peters, Missouri, Zoning and Subdivision Codes, as amended, the St. Peters Property Maintenance Code, as amended, and Chapter 215 of the St. Peters City Code, as amended. For purpose of making the reoccupancy inspection, the building official is authorized to enter, examine and survey the dwelling unit and all common areas thereto, if any, by appointment with the knowledge of the owner thereof, and, if occupied, the tenant. Should any owner, tenant, occupant or other person in charge of a dwelling unit, the common areas thereto, or building or structure fail or refuse to permit free access and entry to the dwelling unit and all common areas, if any, under control for any reoccupancy inspection pursuant to this Code, then the building official may seek a search warrant or other appropriate court order authorizing such reoccupancy inspections. Under this Section, common areas shall not be subject to independent inspection but shall only be inspected in conjunction with the reoccupancy inspection of a dwelling unit.
R110.1.2.3 Reoccupancy Permit And Inspection Fees.
At the time of filing an application for a reoccupancy permit, a reoccupancy permit and inspection fee as set out in Appendix A of this Title shall be charged and collected. No reoccupancy permit shall be valid until such reoccupancy permit and inspection fee as set out in Appendix A of this Title has been paid.
R110.1.2.4 Issuance of Reoccupancy Permit.
If, upon completion of the reoccupancy inspection of the dwelling unit and the common areas thereto, if applicable, the building official finds that the dwelling unit is in compliance with the City of St. Peters, Missouri, Zoning and Subdivision Codes, as amended, the St. Peters Property Maintenance Code, as amended, and Chapter 215 of the St. Peters City Code, as amended, the building official shall, as soon as practicable, issue a reoccupancy permit therefor which shall contain at least the following:
1.	The reoccupancy permit number;
2.	The address of the principal building or structure to which the subject dwelling unit is located;
3.	The name and address of the owner;
4.	A description of the dwelling unit and common areas, if applicable, for which the reoccupancy permit is issued;
5.	A statement that the described dwelling unit and common areas, if applicable, have been inspected for compliance with the requirements of this Code;
6.	The date of such reoccupancy inspection;
7.	The name of the building official;
8.	The edition of the code under which the permit was issued;
9.	If an automatic sprinkler system is provided and whether the sprinkler system is required; and
10.	Any special stipulations and conditions of the reoccupancy permit.
If the building official finds that the dwelling unit is not in compliance with any requirement of the City of St. Peters, Missouri, Zoning and Subdivision Codes, as amended, the St. Peters Property Maintenance Code, as amended, or Chapter 215 of the St. Peters City Code, or any combination or combinations thereof, have not been met or if a violation is found, the building official shall transmit or cause to be transmitted to the owner a written denial specifying the defect(s) or violation(s), or both. If a defect or violation is found, the owner shall be given a reasonable length of time to make repairs and bring the dwelling unit or common areas, if applicable, or both, into compliance prior to reinspection. No final reoccupancy permit shall be issued until the dwelling unit and the common areas thereto, if applicable, complies or comply with the requirements of Section R110.1.2.2.1. Issuance of a reoccupancy permit shall not be construed as an approval of a violation of the provisions of this code or of other ordinances of the City. Reoccupancy permits presuming to give authority to violate or cancel the provisions of this code or other ordinances of the City shall not be valid.

37.

R110.1.3 Suspension Or Revocation. The building official is authorized to, and the building official shall, in writing, suspend or revoke a reoccupancy permit issued under the provisions of this code wherever the reoccupancy permit is issued in error or on the basis of incorrect, inaccurate or incomplete information, or in violation of any ordinance or regulation or any of the provisions of this Code, as amended.

[Ord. No. 7490, 8-26-2021]

38.

R110.1.4 Exceptions.

[Ord. No. 7490, 8-26-2021]

The provisions of Sections R110.1.1 to R110.1.3 hereof shall not apply to the following:
1.	Lawful occupancies existing at the time of the effective date of such Sections; or
2.	An owner-occupied dwelling unit used exclusively for residential purposes, and wherein no home occupation is conducted. For purposes of Sections R110.1.1 to R110.1.3, the term "owner-occupied dwelling unit" shall mean a dwelling unit for which the occupant thereof is expressly named as an owner of the dwelling unit, or is a trustee or beneficiary of a trust that is expressly named as an owner of the dwelling unit, all as indicated upon the deed of record on file in the Office of the Recorder of Deeds of St. Charles County, Missouri.

39.

R112 Board Of Appeals. (Refer to Chapter 410 of Title IV: Land Use).

R112.1 — Delete.

R112.2 — Delete.

R112.3 — Delete.

R112.4 — Delete.

40.

R113.4 Violations, Penalties. Any person who shall violate a provision of this code or shall fail to comply with any requirement thereof or who shall erect, construct, alter or repair a building or structure in violation of approved construction documents or directive of the Code Official, or of a permit or certificate issued under the provisions of this code, shall be guilty of an offense. Each day that a violation continues after due notice has been served shall constitute a separate offense.

41.

R114.2 Unlawful Continuance. Any person who shall continue any work in or about the structure after having been served with a stop work order, except such work that person is directed to perform to remove a violation or unsafe condition, shall be guilty of an offense.

42.

R202 Definitions. Amend.

PERSON

An individual, heirs, executors, trustee, administrators or assigns, its or their successors or assigns, or the agent of any of the aforesaid. The term "person" shall also mean a firm, partnership, copartnership, company, corporation, association, joint stock company, joint venture, trust, estate, organization or combination of individuals, of any kind, character, form or nature whatsoever, its or their successors or assigns, or an officer, manager, member, partner, employee, executor, trustee, administrator or agent of any of the aforesaid.

[Ord. No. 7490, 8-26-2021]

ROUGH-IN

The installation of all parts of the plumbing system that must be completed prior to covering from view. This includes DWV, water supply and built-in fixture supports. DWV shall be the minimum installation in an unfinished area.

43.

R302.1 Exterior Walls. Construction, projections, openings and penetrations of exterior walls of dwellings and accessory building shall comply with Table R302.1(1); or dwellings equipped throughout with an automatic sprinkler system installed in accordance with Section P2904 shall comply with Table R302.1(2).

Exceptions:

1.	Walls, projects, openings or penetrations in walls perpendicular to the line used to determine the fire separation distance.
2.	Walls of dwellings and accessory structures located on the same lot.
3.	Detached tool shed and storage sheds, playhouses and similar structures exempted from permits are not required to provide wall protection based on location on the lot. Projections beyond the exterior wall shall not extend over the lot line.
4.	Detached garages accessory to a dwelling located within two (2) feet (610 mm) of a lot line are permitted to have roof eave projections not exceeding four (4) inches (102 mm).
5.	Foundation vents installed in compliance with this code are permitted.
6.	Cantilevered manufactured fireplaces.
7.	Uncovered decks.

44.

R302.2 Townhouses. Common walls separating townhouses shall be assigned a fire-resistance rating in accordance with Section R302.2, Item 1 or 2. The common wall shared by two (2) townhouses shall be constructed without plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be in accordance with Chapter 34 through 43. Penetrations of the membrane of common walls for electrical outlet boxes shall be in accordance with Section R302.4.

1.	Where a fire sprinkler system in accordance with Section P2904 is provided, the common wall shall be not less than a one-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263.
2.	Where a fire sprinkler system in accordance with Section P2904 is not provided, the common wall shall be not less than a two-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263, or the common wall shall be two (2) independent one-hour fire-resistance-rated wall assemblies.

45.

R302.5.1 Opening Protection. Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than one and three-eighths (1 3/8) inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than one and three-eighths (1 3/8) inches (35 mm) thick, or twenty-minute fire-rated doors.

46.

R302.13 Fire Protection Of Floors. Floor assemblies that are not required elsewhere in this code to be fire-resistance rated, shall be provided with one-half (1/2) inch (12.7 mm) gypsum wallboard membrane, five-eighths (5/8) inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member. Penetrations or openings for ducts, vents, electrical outlets, lighting, devices, luminaires, wires, speakers, drainage, piping and similar openings or penetrations shall be permitted. Fire blocking, draft stopping, fire taping, and/or additional framing is not required.

Exceptions:

1.	Floor assemblies located directly over a space protected by an automatic sprinkler system in accordance with Section P2904, NFPA 13D, or other approved equivalent sprinkler system.
2.	Floor assemblies located directly over a crawl space not intended for storage or fuel-fired appliances.
3.	Portions of floor assemblies shall be permitted to be unprotected where complying with the following:
	3.1	The aggregate area of the unprotected floor assembly does not exceed one hundred (100) square feet per HVAC zone.
	3.2	Areas of the floor assembly covered by HVAC metal plenum, trunk lines, and steel structural beams shall be considered protected. Gypsum wallboard membrane shall be within two (2) inches of all previously listed items.
4.	Wood floor assemblies using dimension lumber or structural composite lumber equal to or greater than two (2) inch by ten (10) inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.

47.

R303.4 Mechanical Ventilation. Where the air infiltration rate of a dwelling unit is less than five (5) air changes per hour where tested with a blower door at a pressure of two-tenths (0.2) inch w.c (50 Pa) in accordance with Section N1102.4.1.2, the dwelling unit shall be provided with whole-house mechanical ventilation in accordance with Section M1507.3.

48.

R303.5.2 Exhaust Openings. Exhaust air shall not be directed below six (6) feet and eight (8) inches onto public walkways.

49.

R303.8 Exterior Stairway Illumination. Exterior stairways shall be provided with an artificial light source. Exterior stairways providing access to a basement from the outdoor grade level shall be provided with an artificial light sources located at the bottom landing of the stairway.

50.

R306.5 Hose Bib. Every dwelling unit shall provide a minimum of one (1) frost-proof hose bib, which shall be protected from backflow per Section P2902.4.3.

51.

R306.6 Floor Drain. All basements and laundry areas shall have a floor drain.

52.

R309.5 Fire Sprinklers. Private garages shall be protected by fire sprinklers where the garage wall has been designed based on Table 302.1(2), Footnote a, and the homeowner has opted to purchase a fire sprinkler system for their resident, as per Missouri Revised Statutes Section 67.281. Sprinklers in garages shall be connected to an automatic sprinkler system that complies with Section P2904. Garage sprinklers shall be residential sprinklers or quick-response sprinklers, designed to provide a density of 0.05 gpm/ft². Garage doors shall not be considered obstructions with respect to sprinkler placement.

53.

Floors And Landings At Exterior Doors. There shall be a landing or floor at each side of each exterior door. The width of each landing shall not be less than the door served. Every landing shall have a dimension of not less than thirty-six (36) inches (914 mm) measured in the direction of travel. The slope at exterior landings shall not exceed one fourth (1/4) unit vertical in twelve (12) units horizontal two percent (2%).

Exceptions:

1.	Exterior balconies less than sixty (60) square feet (5.6 m²) and only accessible from a door are permitted to have a landing less than thirty-six (36) inches (914 mm) measured in the direction of travel.
2.	Doors that are not required egress doors and are served by a stairway of no more than four (4) risers.
3.	Doors protected by a guard in accordance with this code.
4.	Doors protected in a manner approved by the Code Official.

54.

R311.3.2. Floor Elevations For Other Exterior Doors. Doors other than the required egress door shall be provided with landings or floors not more than seven and three-fourths (7 3/4) inches (196 mm) below the top of the threshold.

Exception: A top landing is not required where a stairway of four (4) or fewer risers is located on the exterior side of the door, provided the door does not swing over the stairway.

55.

R311.3.2.1 Future Deck/Balcony. Doors installed for a future deck/balcony with raised floor surface more than thirty (30) inches (762 mm) above grade shall be protected in accordance with Section R312, or made inoperable to open more than four (4) inches clear.

56.

R312.3 Opening Limitations. Required guards shall not have openings from the walking surface to the required guard height which allow passage of a sphere four (4) inches (102 mm) in diameter. Guards shall not have an ornamental pattern or horizontal rails that would provide a ladder effect, as determined by the Code Official.

Exceptions:

1.	The triangular openings at the open side of a stair, formed by the riser, tread and bottom rail of a guard, shall not allow passage of a sphere six (6) inches (153 mm) in diameter.
2.	Guards on the open sides of stairs shall not have openings which allow passage of a sphere four and three-eighths (4 3/8) inches (111 mm) in diameter.

57.

R313.1 Townhouse Automatic Fire Sprinkler Systems. Notwithstanding the provisions of the Building Code and International Residential Code, as amended and adopted by the City of St. Peters, Missouri, a builder of one- or two-family dwellings shall offer to any purchaser on or before the time of entering into the purchase contract the option, at the purchaser's cost, to install or equip fire sprinklers in the dwelling, residence, or unit. Notwithstanding any other provision of law to the contrary, no purchaser of such a one- or two-family dwelling shall be denied the right to choose or decline to install a fire sprinkler system in such dwelling or residence being purchased.

58.

R313.1.1 Additions And Alterations To Townhouses With Existing Automatic Fire Sprinkler Systems. An automatic residential fire sprinkler system shall be designed and installed per Section R313.1.2.

Exception: An automatic residential fire sprinkler system shall not be required when additions or alterations are made to existing townhouses that do not have an automatic residential fire sprinkler system installed.

59.

R313.1.2 Design And Installation. Automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with Section P2904 or NFPA 13D.

60.

R313.2 One- And Two-Family Dwelling Automatic Fire Systems. Notwithstanding the provisions of the Building Code and International Residential Code, as amended and adopted by the City of St. Peters, Missouri, a builder of one- or two-family dwellings shall offer to any purchaser on or before the time of entering into the purchase contract the option, at the purchaser's cost, to install or equip fire sprinklers in the dwelling, residence, or unit. Notwithstanding any other provision of law to the contrary, no purchaser of such a one- or two-family dwelling shall be denied the right to choose or decline to install a fire sprinkler system in such dwelling or residence being purchased.

Exception: An automatic residential fire sprinkler system shall not be required for additions or alterations to existing buildings that are not already provided with an automatic residential fire sprinkler system.

61.

R313.2.1 Additions And Alterations To One- And Two-Family Dwellings With Existing Automatic Fire Sprinkler Systems. An automatic residential fire sprinkler system shall be designed and installed per Section R313.2.2.

62.

R313.2.2 Design And Installation. Automatic residential fire sprinkler systems shall be designed and installed in accordance with Section P2904 or NFPA 13D.

63.

R315.2 Alterations, Repairs And Additions. When alterations, repairs or additions requiring a permit occur, or when one (1) or more sleeping rooms are added or created in existing dwellings, the individual dwelling unit shall be provided with carbon monoxide alarms in accordance with Section 315.1.

Exceptions:

1.	Work involving the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck, are exempt from the requirements of this Section.
2.	Installation, alteration or repairs of plumbing or mechanical systems are exempt from the requirements of this Section.

64.

R322 Flood-Resistant Construction. Refer to Chapter 410 Floodplain Management of the Municipal Code of the City of St. Peters.

R322.1 — Delete.

R322.1.1 — Delete.

R322.1.2 — Delete.

R322.1.3 — Delete.

R322.1.4 — Delete.

R322.1.4.1 — Delete.

R322.1.4.2 — Delete.

R322.1.5 — Delete.

R322.1.6 — Delete.

R322.1.7 — Delete.

R322.1.8 — Delete.

R322.1.9 — Delete.

R322.1.10 — Delete.

R322.2 — Delete.

R322.2.1 — Delete.

R322.2.2 — Delete.

R322.2.2.1 — Delete.

R322.2.3 — Delete.

R322.2.4 — Delete.

R322.3 — Delete.

R322.3.1 — Delete.

R322.3.2 — Delete.

R322.3.3 — Delete.

R322.3.4 — Delete.

R322.3.5 — Delete.

R322.3.5.1 — Delete.

R322.3.6 — Delete.

R322.3.7 — Delete.

65.

403.1.1 Minimum Size. The minimum width, W, and thickness, T, for concrete footings shall be in accordance with Tables R403.1(1) through R403.1(4) and Figure R403.1(1) or R403.1.3, as applicable. The footing width shall be based on the load-bearing value of the soil in accordance with Table R401.4.1. Footing projects, P, shall not be less than two (2) inches (51 mm) and shall not exceed the thickness of the footing. Footing thickness and projection for fireplaces shall be in accordance with Section R1001.2. The size of footings supporting piers and columns shall be based on the tributary load and allowable soil pressure in accordance with Table R401.4.1. Footings for wood foundations shall be in accordance with the details set forth in Section R403.2, and Figures R403.1(2) and R403.1(3).

66.

403.1.7 Footings On Or Adjacent To Slopes. The placement of buildings and structures on or adjacent to slopes steeper than one (1) unit vertical in three (3) units horizontal (33.3% slope) shall conform to Sections R403.1.7.1 through R403.1.7.4, or plans as signed and sealed by a registered engineer licensed in the State of Missouri.

67.

Table R403.1(4) Minimum Width Of Concrete, Precast Or Masonry Footings (Inches) For Light-Frame Construction With Pre-Fabricated Roof Trusses.

Minimum Width of Concrete, Precast or Masonry Footings (inches) for Light-Frame Construction with Pre-Fabricated Roof Trusses^a,b,c
	Load-Bearing Value of Soil (psf)
	1,500	2,000	3,000	>4,000
Conventional light-frame construction with pre-fabricated trusses
1 story	12	12	12	12
2 story	15	12	12	12
3 story	23	17	12	12
4-inch brick veneer over light frame or 8-inch hollow concrete masonry
1 story	12	12	12	12
2 story	21	16	12	12
3 story	32	24	16	12
8-inch solid or fully grouted masonry
1 story	16	12	12	12
2 story	29	21	14	12
3 story	42	32	21	16

For SI: one (1) inch equals 25.4 mm. one (1) pound per square foot+0.0479 kPa
a.	Spread footings shall be same thickness as the wall (minimum of eight (8) inches).
b.	Where minimum footing width is twelve (12) inches, use of a single wythe of solid or fully grouted twelve-inch nominal concrete masonry units is permitted.
c.	Snow Load or Roof Live Load shall not exceed twenty (20) psf. If load exceeds twenty (20) psf, designs must be completed by a licensed design professional.

68.

R404.1.2.2 Reinforcement For Foundation Walls. Concrete foundation walls shall be laterally supported at the top and bottom. Horizontal reinforcement shall be provided in accordance with Table R404.1.2(1). Vertical reinforcement shall be provided in accordance with Table R404.1.2(2), R404.1.2(3), R404.1.2(4), R404.1.2(5), R404.1.2(6), R404.1.2(7) or R404.1.2(8). Vertical reinforcement for flat basement walls retaining four (4) feet (1,219 mm) or more of unbalanced backfill is permitted to be determined in accordance with Table R404.1.2(9). For basement walls supporting above-grade concrete walls, vertical reinforcement shall be the greater of that required by Tables R404.1.2(2) through R404.1.2(8) or by Section R611.6 for the above-grade wall. In buildings assigned to Seismic Design Category D0, D1 or D2, concrete foundation walls shall also comply with Section R404.1.4.2.

Exceptions:

Where unstable soil or ground water conditions do not exist, plain concrete foundation walls may be constructed a minimum of eight (8) inches (203 mm) thick where the wall height from the top of the footing to the top of the wall does not exceed eight (8) feet (2,438 mm). A minimum of two (2) No. 4 horizontal reinforcing bars shall be provided in the top and bottom of plain concrete foundation walls. A minimum of two(2) No. 5 reinforcing bars shall be provided around all window and door openings in plain concrete foundation and basement walls. Bars shall extend a minimum twenty-four (24) inches (610 mm) beyond the corners of the openings.

Where unstable soil or ground water conditions do not exist, plain concrete foundation walls may be constructed a minimum of ten (10) inches (254 mm) thick where the wall height from the top of the footing to the top of the wall does not exceed nine (9) feet (2,743 mm). A minimum of two (2) No. 5 reinforcing bars shall be place horizontally in the top, middle, and bottom of the foundation wall. A minimum of two (2) No. 5 reinforcing bars shall be provided around all window and door openings in plain concrete foundation and basement walls. Bars shall extend a minimum of twenty-four (24) inches (610 mm) beyond the corners of the openings.

69.

R404.1.3.2 Reinforcement For Foundation Walls. Concrete foundation walls shall be laterally supported at the top and bottom. Horizontal reinforcement shall be provided in accordance with Table R404.1.2(1). Vertical reinforcement shall be provided in accordance with Table R404.1.2(2), R404.1.2(3), R404.1.2(5), R404.1.2(6), R404.1.2(7) or R404.1.2(8). Vertical reinforcement for flat basement walls retaining four (4) feet (1,219 mm) or more of unbalanced backfill is permitted to be determined in accordance with Table 404.1.2(9). For basement walls supporting above-grade concrete walls, vertical reinforcement shall be the greater of that required by Tables R404.1.2(2) through R404.1.2(8) or by Section R608.6 for the above-grade wall. In buildings assigned to Seismic Design Category D₀, D₁ or D₂ concrete foundation walls shall also comply with Section 404.1.4.2.

Exception: Where unstable soil or ground water conditions do not exist, concrete foundation walls may be constructed in accordance with Table R404.1.2(10).

70.

Table R404.1.2(10) Concrete Foundation Walls.

Maximum Wall Height	Maximum Depth of Unbalanced Backfill	Minimum Nominal Wall Thickness
8'-0"	7'-6" or less	8" (Note a)
9'-0"	8'-6" or less	10" (Note b)
10'0"	9'-6" or less	12" (Note c)

Note a: Concrete foundation walls may be constructed a minimum of nominal eight (8) inches thick where the wall height from the top of the footing to the top of the wall does not exceed eight (8) feet. A minimum of two (2) #4 reinforcing bars shall be place horizontally in the top and bottom of the foundation wall. A minimum of two (2) #5 reinforcing bars shall be provided around all window and door openings in concrete foundation and basement walls; bars shall extend a minimum of twenty-four (24) inches beyond the corners of the openings.

Note b: Concrete foundation walls may be constructed a minimum of nominal ten (10) inches thick. A minimum of two (2) #5 reinforcing bars shall be placed horizontally in the top, middle, and bottom of the foundation wall. A minimum of two (2) #5 reinforcing bars shall be provided around all window and door openings in concrete foundation and basement walls; bars shall extends a minimum of twenty-four (24) inches beyond the corners of the openings.

Note c: Concrete foundation walls may be constructed a minimum of nominal twelve (12) inches thick. A minimum of three (3) #5 reinforcing bars shall be placed horizontally in the top, middle, and bottom of the foundation wall. A minimum of two (2) #5 reinforcing bars shall be provided around all window and door openings in concrete foundation and basement walls; bars shall extend a minimum of twenty-four (24) inches beyond the corners of the openings.

Note d: The concrete minimum wall thickness shall be eight (8) inches for foundation walls in soil classes SC, MH, ML-CL and inorganic CL when maximum wall height is eight (8) feet.

Note e: The concrete minimum wall thickness shall be ten (10) inches for foundation walls in soil classes SC, MH, ML-CL and inorganic CL when the maximum wall height is nine (9) feet.

Note f: The concrete minimum wall thickness shall be twelve (12) inches for foundation walls in soil classes SC, MH, ML-CL and inorganic CL when the maximum wall height is ten (10) feet.

71.

405.1 Concrete Or Masonry Foundations. Drains shall be provided around concrete or masonry foundation that retain earth and enclose habitable or usable spaces located below grade. Drainage tiles, gravel or crushed stone drains, perforated pipe or other approved systems or materials shall be installed at or below the area to be protected and shall discharge by gravity or mechanical means into an approved drainage system. Gravel or crushed stone drains shall extend not less than one (1) foot (305 mm) beyond the outside edge of the footing and six (6) inches (152 mm) above the top of the footing and be covered with an approved filter membrane material. The top of open joints of drain tiles shall be protected with strips of building paper. Except where otherwise recommended by the drain manufacturer, perforated drains shall be surrounded with an approved filter membrane or the filter membrane shall cover the washed gravel or crushed rock covering the drain. Drainage tiles or perforated pipe shall be placed on a minimum of two (2) inches (51 mm) of washed gravel or crushed rock not less than one (1) sieve size larger than the tile joint opening or perforation and covered with not less than six (6) inches (152 mm) of the same material.

Exceptions:

1.	A drainage system is not required where the foundation is installed on well-drained ground or sand-gravel mixture soils according to the Unified Soil Classification System, Group I soils, as detailed in Table R405.1.
2.	Drains provided as detailed in Section 405.1.2 are approved as an alternative method to meet the requirements of this Section.

72.

R405.1.2 Soil Evaluations. An evaluation of the soil for the presence or absence of groundwater is required. The evaluation report shall be based on either a subsurface soil investigation or satisfactory data from adjacent areas together with an inspection of the excavation prior to pouring concrete.

73.

R405.1.2.1 Groundwater Present. Provide drain tile, perforated pipe or other approved foundation drainage systems (such as water channel system) around perimeter of the outside of the foundation and inside the foundation. Drain discharge shall be by gravity to daylight or be connected to a basement floor sump.

74.

R405.1.2.2 No Groundwater Present. Provide drain tile, perforated pipe or other approved foundation drainage systems (such as water channel system) around perimeter of the outside of the foundation or inside the foundation. Drain discharge shall be by gravity to daylight or be connected to a basement floor sump.

75.

R405.1.2.3 Filter Membranes. An approved filter membrane shall be placed over the top of the joints/pipe perforation. The tile/pipe shall be placed on two (2) inches minimum of gravel or crushed stone and have six (6) inches of minimum cover.

76.

R405.1.2.4 Drainage System. A drainage system shall discharge by gravity to daylight or be connected to an approved sump eighteen (18) inches in diameter x twenty-four (24) inches deep with fitted cover). A sump pump shall be provided if the basement is finished or partially finished with pump discharge by an approved method.

77.

R502.2.2.1 Alternate Deck Ledger Connections. Deck ledger connections not conforming to Table R502.2.2.1 shall be designed in accordance with accepted engineering practice. Girders supporting deck joists shall not be supported on deck ledgers. Deck ledgers shall not be supported on stone or masonry veneer. Girders may be support of rim board with positive connected mechanical hangers.

78.

R502.2.2.2 Deck Lateral Load Connection. The lateral load connection required by Section R502.2.2 shall be permitted to be in accordance with Figure R502.2.2.3. Hold-down tension devices shall be installed in not less than two (2) locations per deck, and each device shall have an allowable stress design capacity of not less than one thousand five hundred (1,500) pounds (6672N).

Exception: All decks that are one hundred (100) square feet or less.

79.

Table 507.2 — Delete footnote e.

80.

R507.2.4 Deck Lateral Load Connection. The lateral load connection required by Section R507.1 shall be one (1) of the following methods:

1.	In accordance with Figure R507.2.3(1) with hold-down tension devices installed in not less than two (2) locations per deck, within twenty-four (24) inches of each end of the deck. Each device shall have an allowable stress design capacity of not less than one thousand five hundred (1,500) pounds (6672 N).
2.	In accordance with Figure R507.2.3(2) with hold-down tension devices installed in not less than four (4) locations per deck, and each device shall have an allowable stress design capacity of not less than seven hundred fifty (750) pounds (3336 N).
3.	Using knee braces extending from the floor system to the posts.

81.

Table R602.7.5.

Table 602.7.5
	Ultimate Design Wind Speed and Exposure Category
Maximum Header Span (feet)	<140mph, Exposure B or <130mph, Exposure C	<115mph, Exposure B^b
4	1	1
6	2	1
8	2	1
10	3	2
12	3	2
14	3	2
16	4	2
18	4	2

For header spans between those given above, use the minimum number of full-height studs associated with the larger header span.

The tabulated minimum number of full-height studs is applicable where jack studs are provided to support the header at each end in accordance with Table R602.7(1). Where a framing anchor is used to support the header in lieu of a jack stud in accordance with footnote "d" of Table R602.7(1), the minimum number of full-height studs at each end of a header shall be in accordance with requirements for wind speed <140mph, Exposure B.

82.

R602.12 Simplified Wall Bracing. Buildings meeting all of the conditions listed below shall be permitted to be braced in accordance with this Section as an alternate to the requirements of Section R602.10. The entire building shall be braced in accordance with this Section; the use of other bracing provisions of Section R602.10, except as specified herein, shall not be permitted.

1.	There shall be not more than three (3) stories above the top of a concrete or masonry foundation or basement wall. Permanent wood foundations shall not be permitted.
2.	Floors shall not cantilever more than twenty-four (24) inches (607 mm) beyond the foundation or bearing wall below.
3.	Wall height shall not be greater than a nominal twelve (12) feet when using the minimum required bracing lengths specified in Table 602.12.4.
4.	The building shall have a roof eave-to-ridge height of fifteen (15) feet (4,572 mm) or less.
5.	Exterior walls shall have gypsum board with a minimum thickness of one-half (1/2) inch (12.7 mm) installed on the interior side fastened in accordance with Table R702.3.5.

Exception: Gypsum board is not required for wall bracing on exterior walls in garages.

6.	The structure shall be located in Seismic Design Category A, B or C for detached one- and two-family dwellings or Seismic Design Category A, B or C for townhouses.
7.	Cripple walls shall not be permitted in three-story buildings.

83.

R602.12.2 Sheathing Materials. The following sheathing materials installed on the exterior side of exterior walls shall be used to construct a bracing unit as defined in Section R602.12.3. Mixing materials is prohibited.

1.	Wood structural panels with a minimum thickness of seven-sixteenths (7/16) inch fastened in accordance with Table R602.3(3).
2.	Structural fiberboard sheathing with a minimum thickness of one-half (1/2) inch (12.7 mm) fastened in accordance with Table R602.3(1).

84.

R602.12.3 Bracing Unit. A bracing unit shall be a full-height sheathed segment of the exterior wall without openings or vertical or horizontal offsets and a minimum length as specified herein. Interior walls shall not contribute toward the amount of the required bracing. Mixing of Items 1 and 2 is prohibited on the same story.

1.	Where all framed portions of all exterior walls are sheathed in accordance with Section R602.12.2, including wall areas between bracing units, above and below openings and on gable end walls, the minimum length of a bracing unit shall be three (3) feet (914 mm). For walls with heights greater than a nominal ten (10) feet, the minimum length of a bracing unit shall be four (4) feet (1,219 mm).
2.	Where the exterior walls are braced with sheathing panels in accordance with Section R602.12.2 and areas between bracing units are covered with other materials, the minimum length of a bracing unit shall be four (4) feet (1,219 mm).

85.

R905.2.8.2 Valleys. Valley linings shall be installed in accordance with the manufacturer's instructions before applying shingles. Valley linings of the following types shall be permitted:

1.	For open valleys (valley lining exposed) lined with metal, the valley lining shall be not less than twenty-four (24) inches (610 mm) wide and of any of the corrosion-resistant metals in Table R905.2.8.2.
2.	For open valley, valley lining of two (2) plies of mineral-surfaced roll roofing, complying with ASTM D 3909 or ASTM D 6380 Class M, shall be permitted. The bottom layer shall be eighteen (18) inches (457 mm) and the top layer not less than thirty-six (36) inches (914 mm) wide.
3.	For closed valleys (valley covered with shingles), valley lining of two (2) ply of No. 15 felt complying with ASTM D 226 Type I, ASTM D 4869 Type I, or ASTM D 6757, or valley lining as described in Item 1 and 2 shall be permitted. Self-adhering polymer modified bitumen underlayment complying with ASTM D 1970 shall be permitted in lieu of the lining material.

86.

R905.2.8.5 Drip Edge. A drip edge shall be provided at eaves and rake edges of shingle roofs. Adjacent segments of drip edge shall be overlapped not less than two (2) inches (51 mm). Drip edges shall extend not less than one-fourth (1/4) inch (6.4 mm) below the roof sheathing and extend up back onto the roof deck not less than two (2) inches (51 mm). Drip edges shall be mechanically fastened to the roof deck at not more than twelve (12) inches (305 mm) o.c. with fasteners as specified in Section R905.2.5. Underlayment shall be installed over the drip edge along eaves and under the underlayment along rake edges.

Exception: For new construction only, a drip edge is not necessary if the metal fascia is bent to form a drip edge.

87.

R1005.7 Factory-Built Chimney Offsets. Where a factory-built chimney assembly incorporates offsets, no part of the chimney shall be at an angle of more than thirty degrees (30°) (0.52 rad) from vertical at any point in the assembly and the chimney shall not include more than four (4) elbows.

Exception: When chimneys are installed per manufacturer's installation instructions.

88.

N1101.6 (R202) Defined Terms.

PROJECTION FACTOR

The ratio of the horizontal depth of an overhang, eave, or permanently attached shading device, divided by the distance measured vertically from the bottom of the fenestration glazing to the underside of the overhang, eave, or permanently attached shading device.

89.

N1101.13 (R401.2) Compliance. Projects shall comply with one (1) of the following:

1.	Sections N1101.14 through N1104 as amended.
2.	Section N1105 and the provisions of Sections N1101.14 through N1104 labeled "Mandatory."
3.	An energy rating index (ERI) approach in Section N1106.

90.

N1101.14 (R401.3) Certificate (Mandatory). A permanent certificate shall be completed by the builder or registered design professional and posted on a wall in the space where the furnace is located, a utility room or an approved location inside the building, unless otherwise presented to the homeowner or Code Official, in writing. Where located on an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit director label, service disconnect label or other required labels. The certificate shall list the predominant R-values of insulation installed in or on ceiling/roof, walls, foundation (slab, basement wall, crawl space wall and/or floor) and ducts outside conditioned spaces; U-factors for fenestration and the solar heat gain coefficient (SHGC) of fenestration, and the results from any required duct system and building envelope air leakage testing done on the building. Where there is more than one (1) value for each component, the certificate shall list the value covering the largest area. The certificate shall list the types and efficiencies of heating, cooling and service water heating equipment. Where a gas-fired unvented room heater, electric furnace, or baseboard electric heater is installed in the residence, the certificate shall list "gas-fired unvented room heater," "electric furnace" or "baseboard electric heater," as appropriate. An efficiency shall not be listed for gas-fired unvented room heaters, electric furnaces or electric baseboard heaters.

91.

Table N1102.1.2 (R402.1.2).

Table N1102.1.2 (R402.1.2)
Insulation and Fenestration Requirements by Component^a
Climate Zone	Fenest- ration U-Factor^b	Skylight^b U-Factor	Glazed Fenest- ration SHGC^b,c	Ceiling R-Value	Wood Frame Wall R-Value	Mass Wall R-Valueⁱ	Floor R-Value	Base- ment^c Wall R-Value	Slab^d R-Value and Depth	Crawl Space^c Wall R-Value
1	NR	0.75	0.25	30	13	3/4	13	0	0	0
2	0.40	0.65	0.25	38	13	4/6	13	0	0	0
3	0.35	0.55	0.25	38	20 or 13 + 5^h	8/13	19	5/13^f	0	5/13
4 except Marine	0.40	0.55	NR	38	13	8/13	19	0^j	10,2 ft	10/13
5 and Marine 4	0.32	0.55	NR	49	20 or 13 + 5^h	13/17	30^g	15/19	10, 2 ft	15/19
6	0.32	0.55	NR	49	20 + 5 Or 13 + 10^h	15/20	30^g	15/19	10, 4 ft	15/19
7 and 8	0.32	0.55	NR	59	20 + 5 Or 13 + 10^h	19/21	38^g	15/19	10, 4 ft	15/19

For SI: one (1) foot — 304.8 mm.
a.	R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the installed R-value of the insulation shall not be less than the R-value specified in the table.
b.	The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
	Exception: Skylights may be excluded from glazed fenestration SHGC requirements in Climate Zones 1 through 3 where the SHGC for such skylights does not exceed 0.30.
c.	"15/19" means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. "15/19" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the home. "10/13" means R-10 continuous insulation on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall.
d.	R-5 shall be added to the required slab edge R-values for heated slabs. Insulation depth shall be the depth of the footing or two (2) feet, whichever is less in Zones 1 through 3 for heated slabs.
e.	There are no SHGC requirements in the Marine Zone.
f.	Basement wall insulation is not required in warm-humid locations as defined by Figure N1101.10 or Table N1101.10.
g.	Or insulation sufficient to fill the framing cavity, R-19 minimum.
h.	The first value is cavity insulation, the second value is continuous insulation, so "13 + 5" means R-13 cavity insulation plus R-5 continuous insulation.
i.	The second R-value applies when more than half of the insulation is on the interior of the mass wall.
j.	Band boards and cripple walls shall be insulated to R-13.

92.

N1102.1.3 R-Value Computation. Insulation material used in layers, such as framing cavity insulation, or continuous insulation shall be summed to compute the corresponding component R-value. The manufacturer's settled R-value shall be used for flown insulation. Computed R-values may include an R-value for other building materials or air films. Where insulated siding is used for the purpose of complying with the continuous insulation requirements of Table N1102.1.2, the manufacturer's labeled R-Value for insulated siding shall be reduced by R-0.6.

93.

N1102.1.5 (R402.1.5) Total UA Alternative. If the total building envelope UA (sum of U-factor times assembly area) is less than or equal to the total UA resulting from using the U-factors in Table N1102.1.4 (multiplied by the same assembly area as in the proposed building), the building shall be considered in compliance with Table N1102.1.2. The UA calculation shall be done using a method consistent with the ASHRAE Handbook of Fundamentals and shall include the thermal bridging effects of framing materials. The SHGC requirements shall be met in addition to UA compliance.

Exception: Glazed Fenestration SHGC. In Climate Zone 4, permanently shaded vertical fenestration shall be permitted to satisfy SHGC requirements. The project factor of an overhang, eave, or permanently attached shading device shall be greater than or equal to the value listed in Table N1102.2.2.1 for the appropriate orientation. The minimum projection shall extend beyond each side of the glazing a minimum of twelve (12) inches. Each orientation shall be rounded to the nearest cardinal orientation (+/- 45° or 0.79 rad) for purposes of calculations and demonstrating compliance.

94.

N1102.2.4 (R402.2.4) Access Hatches And Doors. Access doors from conditional spaces to unconditioned spaces such as attics and crawl spaces shall be insulated to a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood-framed or equivalent baffle or retainer is required to be provided when loose-fill insulation is installed, the purpose of which is to prevent the loose-fill insulation from spilling into the living space when the attic access is opened, and to provide the permanent means of maintaining the installed R-value of the loose-fill insulation.

Exception: Vertical doors that provide access from the conditioned to unconditioned spaces shall be permitted to meet the fenestration requirement of Table R1102.1.2 based on the applicable climate zone specified in Chapter 3.

95.

N1102.4 (R402.4) Air Leakage. The building thermal envelope may be designed and constructed to limit air leakage in accordance with the requirements of Sections R1102.4.1 through R1102.4.4.

96.

Table N1102.4.1.1 (402.4.1.1).

Table N1102.4.1.1 (402.4.1.1) Air Barrier and Insulation Installation
Component	Air Barrier Criteria	Insulation Installation Criteria
General Requirements	A continuous air barrier shall be installed in the building envelope. The exterior thermal envelope contains a continuous air barrier. Breaks or joints in the air barrier shall be sealed.	Air-permeable insulation shall not be used as a sealing material.
Ceiling/attic	The air barrier in any dropped ceiling/soffit shall be aligned with the insulation and any gaps in the air barrier sealed. Access openings, drop down stairs or knee wall doors to unconditioned attic spaces shall be sealed.	The insulation in any dropped ceiling/soffit shall be aligned with the air barrier.
Walls	The junction of the foundation and sill plate shall be sealed. The junction of the top plate and the top of the exterior walls shall be sealed. Knee walls shall be sealed.	Cavities within corners and headers of frame walls shall be insulated by completely filling the cavity with a material having a thermal resistance of R-3 per inch minimum. Exterior thermal envelope insulation for framed walls shall be installed in substantial contact and continuous alignment with the air barrier.
Windows, skylights and doors	The space between window/door jambs and framing, and skylights and framing shall be sealed.
Rim joists	Rim joists shall include the air barrier.	Rim joists shall be insulated.
Floors (including above garage and cantilevered floors)	The air barrier shall be installed at any exposed edge of insulation.	Floor framing cavity insulation shall be installed to maintain permanent contact with the underside of subfloor decking, or floor framing cavity insulation shall be permitted to be in contact with the top side of sheathing, or continuous insulation installed on the underside of floor framing; and extends from the bottom to the top of all perimeter floor framing members.
Crawl space walls	Exposed earth in unvented crawl spaces shall be covered with Class I vapor retarder with overlapping joists taped.	Where provided instead of floor insulation, insulation shall be permanently attached to the crawl space walls.
Narrow cavities		Batts in narrow cavities shall be cut to fit, or narrow cavities shall be filled by insulation that on installation readily conforms to the available cavity space.
Garage separation	Air sealing shall be provided between the garage and conditioned spaces.
Plumbing and wiring		Batt insulation shall be cut neatly to fit around wiring and plumbing in exterior walls, or insulation that on installation readily conforms to available space shall extend behind piping and wiring.
Shower/tub on exterior wall	The air barrier installed at exterior walls adjacent to showers and tubs shall separate them from showers and tubs.	Exterior walls adjacent to showers and tubs shall be insulated.
Electrical/phone box on exterior walls	The air barrier shall be installed behind electrical or communication boxes or air-sealed boxes shall be installed.
Concealed sprinklers	When required to be sealed, concealed fire sprinklers shall only be sealed in a manner that is recommended by the manufacturer. Caulking or other adhesive sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.

a.	In addition, inspection of log walls shall be in accordance with the provisions of ICC 400.

97.

N1102.4.1.2 (R402.4.1.2) Testing Option. If testing is elected, the building or dwelling unit may be tested and verified as having an air leakage rate of not exceeding five (5) air changes per house in Climate Zone 4. Testing shall be conducted in accordance with ASTM E 779 or ASTM E 1827 and reported at a pressure of 0.2 inch w.g. (50 Pascals). Where required by the Code Official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the Code Official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope.

During testing:

1.	Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures.
2.	Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures.
3.	Interior doors, if installed at the time of the test, shall be open.
4.	Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed.
5.	Heating and cooling systems, if installed at the time of the test, shall be turned off.
6.	Supply and return registers, if installed at the time of the test, shall be fully open.

98.

N1102.4.2.1 Visual Inspection Option. The items listed in Table N1102.4.2, applicable to the method of construction, are field verified, by the builder or a party independent from the installer of the insulation, shall inspect the air barrier and insulation.

99.

N1102.4.4 (R402.4.4) Rooms Containing Fuel-Burning Appliances. In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to open combustion fuel-burning appliances, the appliances and combustion air opening shall be located outside the building thermal envelope or enclosed in a room, isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table N1102.1.2, where the walls, floors and ceiling shall meet a minimum of the basement wall R-value requirement. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section N1103. The combustion air duct shall be insulated where it passes through conditioned space to a minimum of R-8.

Exceptions:

1.	Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
2.	Fireplaces and stoves complying with Sections N1102.4.2 and R1006.
3.	Mechanical equipment in an unfinished space.

100.

N1103.1.1 — Delete.

101.

N1103.3.3 (R403.3.3) Duct Testing (Optional). Ducts shall be pressure tested to determine the air leakage by one (1) of the following methods:

1.	Rough-in test: Total leakage shall be measured with a pressure differential of one-tenth (0.1) inch w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure if installed at the time of the test. All registers shall be taped or otherwise sealed during the test.
2.	Postconstruction test: Total leakage shall be measured with a pressure differential of one-tenth (0.1) inch w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure. Registers shall be taped or otherwise sealed during the test.

Exception: A duct air leakage test shall not be required where ducts and air handlers are located entirely within the building thermal envelope.

102.

N1103.3.5 (R403.3.5) — Delete.

103.

N1103.4.1 (R403.4.1) Protection Of Piping Insulation. Piping insulation exposed to weather shall be protected from damage, including that caused by sunlight, moisture, equipment maintenance and wind, and shall provide shielding from solar radiation that can cause degradation of the material. Adhesive tape shall not be permitted.

Exception: Line sets between the structure and the condensing unit.

104.

1103.5.3 (R405.5.3) Hot Water Pipe Insulation (Prescriptive). Insulation for hot water pipe with a minimum thermal resistance (R-value) of R-3 shall be applied to the following:

1.	Piping larger than 3/4 inch (19 mm) in nominal diameter.
2.	Piping serving more than one (1) dwelling unit.
3.	Piping located outside the conditioned space.
4.	Piping from the water heater to a distribution manifold.
5.	Piping located under a floor slab.
6.	Buried in piping.
7.	Supply and return piping in recirculation systems other than demand recirculation systems.

105.

N1103.6 (R403.6) Mechanical Ventilation. Mandatory where required by N1102.4.1.2. If, in accordance with N1102.4.1.2, the resulting air changes per hour (ACH) at fifty (50) Pascals is less than five (5) air changes per hour, the building shall be provided with ventilation that meets the requirements of Section M1507 of this code or the International Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

106.

N1103.6.1 (R403.6.1) — Delete.

107.

Table N1103.6.1 (R403.6.1) — Delete.

108.

N1104 (R404) Electrical Power And Lighting Systems (Optional).

109.

N1104.1 (R404.1) Lighting Equipment (Optional). Not less than seventy-five percent (75%) of the lamps in permanently installed lighting fixtures shall be high efficacy lamps or not less than seventy-five percent (75%) of the permanently installed lighting fixtures shall contain only high efficacy lamps.

Exception: Low voltage lighting.

110.

N1104.1.1 (R404.1.1) Lighting Equipment (Optional). Fuel gas lighting systems shall not have continuously burning pilot lights.

111.

Table N1105.5.2(1) [R405.5.2(1)].

Table N1105.5.2(1) [R405.5.2(1)] Specifications for the Standard Reference and Proposed Designs
Building Component	Standard Reference Design	Proposed Design
Above-grade walls	Type: mass wall if proposed wall is mass; otherwise wood frame	As proposed
	Gross area: same as proposed	As proposed
	U-factor: as specified in Table N1102.1.4	As proposed
	Solar absorptance = 0.75	As proposed
	Remittance = 0.90	As proposed
Basement and crawl space walls	Type: same as proposed	As proposed
	Gross area: same as proposed	As proposed
	U-factor: from table N1102.1.4, with insulation layer on interior side of walls	As proposed
Above-grade floors	Type: wood frame	As proposed
	Gross area: same as proposed	As proposed
	U-factor: as specified in Table N1102.1.4	As proposed
Ceilings	Type: wood frame	As proposed
	Gross area: same as proposed	As proposed
	U-factor: as specified in Table N1102.1.4	As proposed
Roofs	Type: composition shingle on wood sheathing	As proposed
	Gross area: same as proposed	As proposed
	Solar absorptance = 0.75	As proposed
	Emittance = 0.90	As proposed
Attics	Type: vented with aperture = 1 ft² per 300 ft² ceiling area	As proposed
	Type: same as proposed	As proposed
Foundations	Foundation wall area above and below grade and soil characteristics: same as proposed	As proposed
Opaque doors	Area: 40 ft²	As proposed
	Orientation: North	As proposed
	U-factor: same as fenestration from Table N1102.1.4	As proposed
Vertical fenestration other than opaque doors	Total area^b = 15% of the conditioned floor area	As proposed
	Orientation: equally distributed to four (4) cardinal compass orientations (N, E., S & W)	As proposed
	U-factor: as specified in Table N1102.1.4	As proposed
	SHGC: as specified in Table N1102.1.2 except that for climates with no requirement (NR) SHGX = 0.40 shall be used	As proposed
	Interior shade fraction: 0.92 — (0.21 x SHGC for the standard reference design)	0.92 — (0.21 x SHGC as proposed)
	External shading: none	As proposed
Skylights	None	As proposed
Thermally isolated sunrooms	None	As proposed
Air exchange rate	Air leakage rate of five (5) air changes per hour in Climate Zone 4. The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 x CFA + 7.5 x (N_br + 1) where: CFA = conditional floor area N_br = number of bedrooms Energy recovery shall not be assumed for mechanical ventilation	For residences that are not tested, the same air leakage rate as the standard reference design. For tested residences, the measured air exchange rate^a. The mechanical ventilation rate rate^b shall be in addition to the air leakage rate and shall be proposed.
Mechanical ventilation	None, except where mechanical ventilation is specified by the proposed design, in which case: Annual vent fan energy use: KWh/yr = 0.03942 x CFA + 29.565 x (N_br + 1) where: CFA = conditional floor area N_br = number of bedrooms	As proposed
Internal gains	IGain = 17,900 + 23.8 x CFA + 4104 x N_br (Btu/day per dwelling unit)	Same as standard reference design
Internal mass	An internal mass for furniture and contents of 8 pounds per square foot of floor area	Same as standard reference design, plus any additional mass specifically designed as a thermal storage element^c but not integral to the building envelope or structure
Structural mass	For masonry floor slabs, 80% of floor area covered by R-2 carpet and pad, and 20% of floor directly exposed to room air	As proposed
	For masonry basement walls, as proposed, but with insulation required by Table R402.1.4 located on the interior side of the walls	As proposed
	For other walls, for ceilings, floors, and interior walls, wood frame construction	As proposed
Heating systems^{d, e}	Fuel type: same as the proposed design Efficiencies: Electric: air-source heat pump with prevailing Federal minimum standards Non-electric Furnaces: natural gas furnace with prevailing Federal minimum standards Non-electric boilers: natural gas boiler with prevailing Federal minimum standards Capacity: sized in accordance with Section N1103.7	As proposed
Cooling systems^{d, f}	Fuel type: electric Efficiency: in accordance with prevailing Federal minimum standards Capacity: sized in accordance with Section N1103.7	As proposed
Service water heating^{d, e, f}	Fuel type: same as proposed design Efficiency: in accordance with prevailing Federal minimum standards Use: gal/day = 30 + 10 x N_br Tank temperature: 120° F.	As proposed Same as standard reference
Thermal distribution systems	Duct insulation: from Section N1103.2.1 A thermal distribution system efficiency (DSE) of 0.88 shall be applied to both the heating and cooling system efficiencies for all systems other than tested duct systems. For tested duct systems, the leakage rate shall be 4 cfm (113.3 L/min) per 100 ft² (9.29 m²) of conditioned floor area at a pressure of differential of one tenths (0.1) inches w.g. (25 Pa)	As tested or specified in Table R405.5.2(2) if not tested. Duct insulation shall be as proposed
Thermostat	Type: Manual, cooling temperature setpoint = 75° F. Heating temperature setpoint = 72° F.	Same as standard reference

For SI: 1 square foot = 0.93 m2, 1 British thermal unit = 1055 J, 1 pound per square foot = 4.88 kg/m2, 1 gallon (US) = 3.785 L, °C = (°F-32)/1.8, 1 degree = 0.79 rad.
a.	Where required by the Code Official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent shall be used to determine the energy loads resulting from infiltration.
b.	The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.
c.	Thermal storage element shall mean a component not part of the floors, walls or ceilings that is part of a passive solar system, and that provides thermal storage such as enclosed water columns, rock beds, or phase-change containers. A thermal storage element must be in the same room as fenestration that faces within 15° (0.26 rad) of true south, or must be connected to such a room with pipes or ducts that allow the element to be actively charged.
d.	For a proposed design with multiple heating, cooling or water heating systems using different fuel types, the applicable standard reference design system capacities and fuel types shall be weighted in accordance with their respective loads as calculated by accepted engineering practice for each equipment and fuel type present.
e.	For a proposed design without a proposed heating system, a heating system with the prevailing Federal minimum efficiency shall be assumed for both the standard reference design and proposed design.
f.	For a proposed design home without a proposed cooling system, an electric air conditioner with the prevailing Federal minimum efficiency shall be assumed for both the standard reference design and the proposed design.
g.	For a proposed design with a non-storage-type water heat, a forty-gallon storage-type water heater with the prevailing Federal minimum energy factor for the same fuel as the predominant heating fuel type shall be assumed. For the case of a proposed design without a proposed water heater, a forty-gallon storage-type water heater with the prevailing Federal minimum efficiency for the same fuel as the predominant heating fuel type shall be assumed for both the proposed design and standard reference design.

112.

M1201.3 Licensing of Mechanical Contractors. For licensing requirement refer to Section 515.040 of the Municipal Code of the City of St. Peters.

113.

M1301.2 Identification. — Delete.

114.

M1301.3 Installation Of Materials. — Delete.

115.

M1301.4 Plastic Pipe, Fittings And Components. — Delete.

116.

M1301.5 Third Party Testing And Certification. — Delete.

117.

M1305.1.4.1 Ground Clearance. Equipment and appliances supported from the ground shall be level and firmly supported on a concrete slab or other approved material extending not less than two (2) inches (50.8 mm) above the adjoining ground. Such support shall be in accordance with the manufacturer's installation instructions. Appliances suspended from the floor shall have a clearance of not less than six (6) inches (152 mm) from the ground.

118.

M1305.1.4.3 Electrical Requirements. A luminaire controlled by a switch located at the required passageway opening and a receptacle outlet shall be installed at or near the appliance location in accordance with Chapter 39. Exposed lamps shall be protected from damage by location or lamp guards.

Exception: Basements.

119.

M1307.2 Anchorage Of Appliances. Appliances designed to be fixed in position shall be fastened or anchored in an approved manner. In Seismic Design Categories D₀, D₁ and D₂, water heaters and thermal storage units shall be anchored or strapped to resist horizontal displacement caused by earthquake motion in accordance with one (1) of the following:

Anchorage and strapping shall be designed to resist a horizontal force equal to one-third (1/3) of the operating weight of the water heater storage tank, acting in any horizontal direction. Strapping shall be at points within the upper one-third (1/3) and lower one-third (1/3) of the appliance's vertical dimensions. At the lower point, the strapping shall maintain a minimum distance of four (4) inches (102 mm) above the controls.

The anchorage strapping shall be in accordance with the appliance manufacturer's recommendations.

120.

M1411.3.1 Auxiliary And Secondary Drain Systems. In addition to the requirements of Section M1411.3, a secondary drain or auxiliary drain pan shall be required for each cooling or evaporator coil where damage to any building components will occur as a result of overflow from the equipment drain pan or stoppage in the condensate drain piping. Such piping shall maintain a minimum horizontal slope in the direction of discharge or not less than 1/8 unit vertical in 12 units horizontal (one-percent slope). Drain piping shall be not less than 3/4-inch (19 mm) nominal pipe size. One (1) of the following methods shall be used:

1.	An auxiliary drain pan with a separate drain shall be installed under the coils on which condensation will occur. The auxiliary pan drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain. The pan shall have a minimum depth of one and one-half (1.5) inches (38 mm), shall be not less than three (3) inches (76 mm) larger than the unit or the coil dimensions in width and length and shall be constructed of corrosion-resistant material. Galvanized sheet steel pans shall have a minimum thickness of not less than (No. 26 Gage). Non-metallic pans shall have a minimum thickness of not less than 0.0625 inch (1.6 mm).
2.	A separate overflow drain line shall be connected to the drain pan installed with the equipment. This overflow drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain. The overflow drain line shall connect to the drain pan at a higher level than the primary drain connection.
3.	An auxiliary drain pan without a separate drain line shall be installed under the coils on which condensation will occur. This pan shall be equipped with a water level detection device conforming to UL 508 that will shut off the equipment served prior to overflow of the pan. The pan shall be equipped with a fitting to allow for drainage. The auxiliary drain pan shall be constructed in accordance with Item 1 of this Section.
4.	A water level detection device conforming to UL 508 shall be installed that will shut off the equipment served in the event that the primary drain is blocked. The device shall be installed in the primary drain line, the overflow drain line or the equipment-supplied rain pan, located at a point higher than the primary drain line connection and below the overflow rim of such pan.

121.

M1502.4.1 Material And Size. Exhaust ducts shall have a smooth interior finish and be constructed of metal having a minimum thickness of 0.0157 inch (Answer: 0.3950 mm). The duct shall be four (4) inches (102 mm) nominal in diameter.

122.

M1502.4.2 Duct Installation. Exhaust ducts shall be supported at intervals not to exceed twelve (12) feet (3,658 mm) and shall be secured in place. The insert end of the duct shall extend into the adjoining duct or fitting in the direction of airflow. Exhaust duct joints shall be sealed in accordance with Section M1601.4.1.

123.

M1503.4 Makeup Air Required. Exhaust hood systems capable of exhausting in excess of six hundred (600) cubic feet per minute (0.28 m³/s) shall be mechanically or naturally provided with makeup air at a rate approximately equal to the exhaust air rate. Such makeup air systems shall be equipped with not less than one (1) damper. Each damper shall be a gravity damper or an electrically operated damper that automatically opens when the exhaust system operates. Damper shall be accessible for inspection, service, repair and replacement without removing permanent construction or any other ducts not connected to the damper being inspected, serviced, repaired or replaced.

124.

M1601.1.1 Above-Ground Duct Systems. Above-ground duct systems shall conform to the following:

1.	Equipment connected to duct systems shall be designed to limit discharge air temperature to not greater than 250° F. (121° C.)
2.	Factory-made ducts shall be listed and labeled, as produced by the manufacturer and prior to use in the field, in accordance with UL 181 and installed in accordance with the manufacturer's instructions.
3.	Fibrous glass duct construction shall conform to the SMACNA Fibrous Glass Duct Construction Standards or NAIMA Fibrous Glass Duct Construction Standards.
4.	Field-fabricated and shop-fabricated metal and flexible duct constructions shall conform to the SMACNA HVAC Duct Construction Standards — Metal and Flexible except as allowed by Table M1601.1.1. Galvanized steel shall conform to ASTM A 653.
5.	The use of gypsum products to construct return air ducts or plenums is permitted, provided that the air temperature does not exceed 125° F. (52° C.) and exposed surfaces are not subject to condensation.
6.	Duct systems shall be constructed of materials having a flame spread index of not greater than two hundred (200).
7.	Stud wall cavities and the spaces between solid floor joists to be used as air plenums shall comply with the following conditions:
	7.1.	These cavities or spaces shall not be used as a plenum for air supply.
	7.2.	These cavities or spaces shall not be a part of required fire-resistance-rated assembly.
	7.3.	Stud wall cavities shall not convey air from more than one (1) floor level.
	7.4.	Stud wall cavities and joist-space plenums shall be isolated from adjacent concealed spaces by tight-fitting fireblocking in accordance with Section R602.8.
	7.5.	Stud wall cavities in the outside walls of building envelope assemblies shall not be utilized as air plenums.

125.

Table M1601.1.1.

Table M1601.1.1
Gages of Metal Ducts and Plenums Used For Heating or Cooling
Type of Duct	Size (inches)	Minimum Thickness (inch)	Equivalent Galvanized Sheet	Approximate Aluminum B & S Gage
Round ducts and enclosed rectangular ducts	14 or less	0.013	30	26
	over 14	0.016	28	24
Exposed rectangular ducts	14 or less	0.016	28	24
	over 14	0.019	26	22

For S1 (1 inch = 25.4 mm).

126.

M1601.4.1 Joints, Seams And Connections. Joints of duct systems shall be made substantially airtight in an unconditioned area by means of tapes, mastics, liquid sealants, gasketing or other approved closure systems. Closure systems used with rigid fibrous glass ducts shall comply with UL 181A and shall be marked 18 A-P for pressure-sensitive tape, 181A-M for mastic or 181A-H for heat-sensitive tape. Closure systems used with flexible air ducts and flexible air connectors shall comply with UL181B and shall be marked 181B-FX for pressure-sensitive tape or 181B-M for mastic. Duct connections to flanges of air distribution system equipment or sheet metal fitting shall be mechanically fastened. Mechanical fasteners for use with flexible non-metallic air ducts shall comply with UL 181B and shall be marked 181B-C. Crimp joints for round metal ducts shall have a contact lap of at least one (1) inch and shall be mechanically fastened with at least three (3) sheet metal screws or rivets equally spaced around the joint. Closure systems used to seal metal ductwork shall be installed in accordance with the manufacturer's installation instructions.

Exceptions:

1.	Spray polyurethane foam shall be permitted to be applied without additional joint seals.
2.	Where a duct connection is made that is partially inaccessible, three (3) screws or rivets shall be equally spaced on the exposed portion of the joint so as to prevent a hinge effect.
3.	Continuously welded and locking-type longitudinal joints and seam in ducts operating at static pressure less than two (2) inches of water column (500 Pa) pressure classification shall not require additional closure systems.

127.

M1602.2 Return Air Openings. Return air openings for heating, ventilation and air conditioning systems shall comply with all of the following:

1.	Openings shall not be located less than ten (10) feet (3,048 mm) measured in any direction from an open combustion chamber or draft hood of another appliance located in the same room or space.
2.	Return and transfer openings shall be sized in accordance with the appliance or equipment manufacturer's installation instructions, Manual D or the design of the registered design professional.
3.	Return air shall not be taken from a bathroom, toilet room, kitchen, garage, mechanical room, boiler room, furnace room or unconditioned attic.

Exceptions:
1.	Taking return air from a kitchen is not prohibited where such return air openings serve the kitchen only, and are located not less than ten (10) feet (3,048 mm) from the cooking appliances.
2.	Dedicated forced-air systems serving only the garage shall not be prohibited from obtaining return air from the garage.
3.	Taking return air from an unconditioned crawl space shall not be accomplished through a direct connection to the return side of a forced-air furnace. Transfer openings in the crawl space enclosure shall not be prohibited.
4.	Return air from one (1) dwelling unit shall not be discharged into another dwelling unit.
5.	Return air may be taken from a bedroom closet over sixty-four (64) square feet in area.

128.

M2105.19 Pipe Penetrations. Openings for pipe penetrations in walls, floors and ceilings shall be larger than the penetrating pipe. Openings in the foundation wall underground shall be sealed to not allow groundwater into a building.

129.

G2408.4 (305.7) Clearances From Grade. Equipment and appliances installed at grade level shall be supported on a level concrete slab or other approved material extending not less than two (2) inches (50.8 mm) above adjoining grade or shall be suspended not less than six (6) inches (152 mm) above adjoining grade. Such supports shall be installed in accordance with the manufacturer's installation instructions.

130.

G2409.1 (308.1) Scope. This Section shall govern the reduction in required clearances to combustible materials; and combustible assemblies for chimneys, vents, appliances, devices and equipment. Clearance requirements for air-conditioning equipment and central heating boilers and furnaces shall comply with Sections G2409.3 and G2409.4.

131.

G2412.9 (401.9) Identification. Each length of pipe and tubing, as produced by the manufacturer and prior to use in the field, and each pipe fitting, utilized in a fuel gas system, shall bear the identification of the manufacturer.

132.

G2412.10 (401.10) — Delete.

133.

G2439.7.4.1 (614.8.4.1) Specified Length. The maximum length of the exhaust duct shall be thirty-five (35) feet (10,688 mm) from the connection to the transition duct from the dryer to the outlet terminal. Where fittings are used, the maximum length of the exhaust duct shall be reduced in accordance with Table G2439.7.4.1. The maximum length of the exhaust duct does not include the transition duct.

134.

G2442.4 (618.4) Prohibited Sources. Outdoor or return air for forced-air heating and cooling systems shall not be taken from the following locations:

1.	Closer than ten (10) feet (3,048 mm) from an appliance vent outlet, a vent opening from a plumbing drainage system or the discharge outlet of an exhaust fan, unless the outlet is three (3) feet (914 mm) above the outside air inlet.
2.	Where there is the presence of objectionable odors, fumes or flammable vapors; or where located less than ten (10) feet (3,048 mm) above the surface of any abutting public way or driveway; or where located at grade level by a sidewalk, street, alley or driveway.
3.	A hazardous or insanitary location or a refrigeration machinery room as identified in the International Mechanical Code.
4.	A room or space, the volume of which is less than twenty-five percent (25%) of the entire volume served by such system. Where connected by a permanent opening having an area sized in accordance with Section G2442.2, adjoining rooms or spaces shall be considered as a single room or space for the purpose of determining the volume of such rooms or spaces.

Exception: The minimum volume requirement shall not apply where the amount of return air taken from a room or space is less than or equal to the amount of supply air delivered to such room or space.

5.	A room or space containing an appliance where such a room or space serves as the sole source of return air.
	Exception: This shall not apply where:

1.	The appliance is a direct-vent appliance or an appliance not requiring a vent in accordance with Section G2425.8.
2.	The room or space complies with the following requirements:
	2.1	The return air shall be taken from a room or space having a volume exceeding one (1) cubic foot for each ten (10) Btu/h (9.6L/W) of combined input rating of all fuel-burning appliances therein.
	2.2	The volume of supply air discharged back into the same space shall be approximately equal to the volume of return air taken from the space.
	2.3	Return-air inlets shall not be located within ten (10) feet (3,048 mm) of a draft hood in the same room or space or the combustion chamber of any atmospheric burner appliance in the same room or space.
3.	Rooms or spaces containing solid fuel-burning appliances, provided that return-air inlets are located not less than ten (10) feet (3,048 mm) from the firebox of such appliances.

6.	A closet, bathroom, toilet room, kitchen, garage, boiler room, furnace room or unconditioned attic.

Exceptions:
1.	Where return air intakes are located not less than ten (10) feet (3,048 mm) from cooking appliances and serve only the kitchen area, taking return air from a kitchen area shall not be prohibited.
2.	Dedicated forced-air systems serving only a garage shall not be prohibited from obtaining return air from the garage.
3.	Where a closet is provided with a supply register, taking return air from the closet shall not be prohibited where such closet is sixty-four (64) square feet or greater.

7.	A crawl space by means of direct connection to the return side of a forced-air system. Transfer openings in the crawl space enclosure shall not be prohibited.

135.

P2501.3 Licensing Of Plumbing Contractors. For licensing requirement refer to Section 520.040 of the Municipal Code of the City of St. Peters.

136.

P2503.5.1 Rough Plumbing. DWV systems shall be tested on completion of the rough piping installation by water or by air without evidence of leakage. Either test shall be applied to the drainage system in its entirety or in sections after rough-in piping has been installed, as follows:

1.	Water test. Each section shall be filled with water to a point not less than five (5) feet (1,524 mm) above the highest fitting connection in that section, or to the highest point in the completed system. Water shall be held in the section under test for a period of fifteen (15) minutes. The system shall prove leak free by visual inspection.
2.	Air test. The portion under test shall be maintained at a gauge pressure of five (5) pounds per square inch (psi) (34 kPa) or ten (10) inches of mercury column (34 kPa). This pressure shall be held without introduction of additional air for a period of fifteen (15) minutes.

137.

P2609.1 Identification. Factory-made pipes shall be listed and labeled, as produced by the manufacturer and prior to use in the field, and installed in accordance with the manufacturer's instructions.

Exception: Where the manufacturer identification cannot be marked on pipe fitting and pipe nipples because of the small size of such fittings, the identification shall be printed on the item packaging or on documentation provided with the item.

138.

P2801.8 Water Heater Seismic Bracing. In Seismic Design Categories D₀, D₁ and D₂, water heaters shall be anchored or strapped in the upper one-third (1/3) and in the lower one-third (1/3) of the appliance to resist a horizontal force equal to one-third (1/3) of the operating weight of the water heater, acting in any horizontal direction, or in accordance with the appliance manufacturer's recommendations.

139.

P2804.6.1 Requirements For Discharge Pipe. The discharge piping serving a pressure-relief valve, temperature-relief valve or combination valve shall:

1.	Not be directly connected to the drainage system.
2.	Discharge through an air gap located in the same room as the water heater.
3.	Not be smaller than the diameter of the outlet of the valve served and shall discharge full size to the air gap.
4.	Serve a single relief device and shall not connect to piping serving any other relief device or equipment.
5.	Discharge to the floor, to the pan serving the water heater or storage tank, to a waste receptor or to the outdoors.
6.	Discharge in a manner not to be a hazard; does not cause personal injury, structural damage, or otherwise a nuisance.
7.	Discharge to a termination point that is readily observable by the building occupants.
8.	Not be trapped.
9.	Be installed to flow by gravity.
10.	Terminate not more than six (6) inches (152 mm) and not less than two (2) times the discharge pipe diameter above the floor or waste receptor flood level rim.
11.	Not have a threaded connection at the end of the piping.
12.	Not have valves or tee fittings.
13.	Be constructed of those materials indicated in Section P2906.5 or materials tested, rated and approved for such use in accordance with ASME A112.4.1.
14.	Be one (1) nominal size larger than the size of the relief-valve outlet, where the relief-valve discharge piping is constructed of PEX or PE-RT tubing. The outlet end of such tubing shall be fastened in place.

140.

P2903.5 Water Hammer. The flow velocity of the water distribution system shall be controlled to reduce the possibility of water hammer. A water-hammer arrestor shall be installed where quick-closing valves are used. Water-hammer arrestors shall be installed in accordance with the manufacturer's installation instructions. Water-hammer arrestors shall conform to ASSE 1010.

141.

P2904.1 General. When installed, the design and installation of residential fire sprinkler systems shall be in accordance with NFPA 13D or Section 2904, which shall be considered equivalent to NFPA 13D. Partial residential sprinkler systems shall be permitted to be installed only in buildings not required to be equipped with a residential sprinkler system. Section P2904 shall apply to stand-along and multipurpose wet-pipe sprinkler systems that do not include the use of antifreeze. A multipurpose fire sprinkler system shall provide domestic water to both fire sprinklers and plumbing fixtures. A stand-along sprinkler system shall be separate and independent from the water distribution system.

142.

P3201.2.1 Trap Seal Protection. Traps seals of emergency floor drain traps and traps subject to evaporation shall be protected by one (1) of the methods in Sections P3201.2.1.1 through P3201.2.1.4.

Exception: Basement floor drains with a condensate line draining to it, or with a deep trap seal.

143.

E3401.1.1 Licensing Of Electrical Contractors. (Refer to Chapter 510 of the Municipal Code of the City of St. Peters for licensing requirements.)

144.

E3902.2 Garage And Accessory Building Receptacles. All 125-volt, single-phase, 15- or 20-ampere receptacles installed in garages and grade-level portions of unfinished accessory buildings used for storage or work areas shall have ground-fault circuit-interrupter protection for personnel.

Exception: Fastened in place appliances or outlets designated for refrigerators/freezers, garage door openers, etc.

145.

E3902.5 Unfinished Basement Receptacles. 12-volt, single-phase, 15- and 20-ampere receptacles installed in unfinished basements shall have ground-fault circuit-interrupter protection for personnel. For purposes of this Section, unfinished basements are defined as portions or areas of the basement not intended as habitable rooms and limited to storage areas, work areas, and similar areas.

Exceptions:

1.	A receptacle supplying only a permanently installed fire alarm or burglar alarm system. Receptacles installed in accordance with this exception shall not be considered as meeting the requirements of Section E3901.9.
2.	Fastened in place appliances or outlets designated for refrigerators/freezers.

146.

E3902.6 Kitchen Receptacles. 125-volt, single-phase, 15- and 20-ampere receptacles that serve countertop surfaces shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(6)]

Exception: Fastened in place appliances or outlets designated for refrigerators/freezers.

147.

E3902.9 — Delete.

148.

E3902.10 — Delete.

149.

E3902.14 Location Of Ground-Fault Circuit Interrupters. Ground-fault circuit-interrupters shall be installed only in a readily accessible location.

150.

E3902.16 Arc-Fault Circuit-Interrupter Protection. Branch circuits that supply 120-volt, single-phase, 15- and 20-ampere outlets installed in bedrooms shall be protected by any of the following: [210.12(A)]

1.	A listed combination-type arc-fault circuit-interrupter, installed to provide protection of the entire branch circuit. [210.12(A)(1)]
2.	A listed branch/feeder-type AFCI installed at the origin of the branch-circuit in combination with a listed outlet branch-circuit type arc-fault circuit-interrupter installed at the first outlet box on the branch-circuit. The first outlet box in the branch-circuit shall be marked to indicate that it is the first outlet of the circuit. [210.12(A)(2)]
3.	A listed supplemental arc protection circuit breaker installed at the origin of the branch-circuit in combination with a listed outlet branch-circuit type are-fault circuit-interrupter installed at the first outlet box on the branch-circuit where all of the following conditions are met:
	3.1	The branch-circuit wiring shall be continuous from the branch-circuit overcurrent device to the outlet branch-circuit arc-fault circuit-interrupter.
	3.2	The maximum length of the branch-circuit wiring from the branch-circuit overcurrent device to the first outlet shall not exceed fifty (50) feet (152 m) for 14 AWG conductors and seventy (70) feet (21.3 m) for 12 AWG conductors.
	3.3	The first outlet box in the branch-circuit shall be marked to indicate that it is the first outlet of the circuit. [210.12(A)(3)]
4.	A listed outlet branch-circuit type arc-fault circuit-interrupter installed at the first outlet on the branch circuit in combination with a listed branch-circuit overcurrent protective device where all of the following conditions are met:
	4.1	The branch-circuit wiring shall be continuous from the branch-circuit overcurrent device to the outlet branch-circuit arc-fault circuit-interrupter.
	4.2	The maximum length of the branch-circuit wiring from the branch-circuit overcurrent device to the first outlet shall not exceed fifty (50) feet (15.2 m) for 14 AWG conductors and seventy (70) feet (21.3 m) for 12 AWG conductors.
	4.3	The first outlet box in the branch-circuit shall be marked to indicate that it is the first outlet on the circuit.
	4.4	The combination of the branch-circuit overcurrent device and outlet branch-circuit AFCI shall be identified as meeting the requirements for a system combination-type AFCI and shall be listed as such. [210.12(A)(4)]
5.	Where metal outlet boxes and junction boxes and RMC, IMC, EMT, Type MC or steel-armored Types AC cables meeting the requirements of Section E3908.8, metal wireways or metal auxiliary gutters are installed for the portion of the branch-circuit between the branch-circuit overcurrent device and the first outlet, a listed outlet branch-circuit type AFCI installed at the first outlet shall be considered as providing protection for the remaining portion of the branch-circuit. [210.12(A)(5)]
6.	Where a listed metal or non-metallic conduit or tubing or Type MC cable is encased in not less than two (2) inches (50.8 mm) of concrete for the portion of the branch-circuit between the branch-circuit overcurrent device and the first outlet, a listed outlet branch-circuit type AFCI installed at the first outlet shall be considered as providing protection for the remaining portion of the branch circuit. [210.12(A)(6)]

Exception: AFCI protection is not required for an individual branch-circuit supplying only a fire alarm system where the branch-circuit is wired with metal outlet and junction boxes and RMC, IMC, EMT or steel-sheathed armored cable Type AC or Type MC meeting the requirements of Section E3908.8.

151.

E3902.17 Arc-Fault Circuit-Interrupter Protection For Branch-Circuit Extensions Or Modifications. Where branch-circuit wiring is modified, replaced, or extended in any of the areas specified in Section E3902.16, the branch-circuit shall be protected by one (1) of the following:

1.	A combination-type AFCI located at the origin of the branch-circuit.
2.	An outlet branch-circuit type AFCI located at the first receptacle outlet of the existing branch-circuit.

Exception: AFCI protection shall not be required where the extension of the existing conductors is not more than thirty (30) feet (9.5 m) in length and does not include any additional outlets or devices. [210.12(B) Exception]

152.

E4002.14 — Delete.