Article III: Residential Code For One- And Two-Family Dwellings

Section 500.055 Residential Code — Amendments.

[Ord. No. 2281, 12-20-2023]

The International Residential Code for One- and Two-Family Dwellings, 2021 Edition, as published by the International Code Council, is amended by addition, deletions and changes including the changing of Articles, Sections, Subsections and Subsection titles and the addition of new Sections and Subsections so that such amended and added Articles, Sections and Subsections read as follows:

Chapter 1 Scope and Administration.

Section R101 Scope and General Requirements.

(1)

R101.1. Title. (replace with) These regulations, referenced standards, and appendices AA, AB, AC, AD, AF, AG, AH, AJ, AM, and AP shall be known as the Residential Code for One- and Two-family Dwellings of the City of Dardenne Prairie, Missouri, and shall be cited as such and will be referred to herein as "this code."

Section R102 Applicability.

(1)

R102.1 General. (replace with) Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall govern. Where differences occur between provisions of this code and the referenced standards, the provisions of this code shall apply. Where, in a specific case, different sections of this code or the Municipal Code of Dardenne Prairie specify different requirements, the most restrictive shall govern.

Section R103 Department of Building Safety.

(1)

R103 Department of Building Safety (delete).

Section R105 Permits.

(1)

R105.5.1 Permit extensions. The code official is authorized to grant an extension of time for not more than one hundred eighty (180) days.

(2)

R105.2 Work exempt from permit.

Building:
1.	(Delete and replace with) 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) or two hundred (200) square feet (19 m2) for portable structures.
2.	(Delete)
	...
(Add the following)
11.	Flagpoles forty (40) feet or less in height.
12.	Replacement of doors and windows where the opening size is not increased or decreased.

Section R113 Violations.

(1)

R113.4 Violation Penalties. (delete).

Chapter 3 Building Planning.

Section R301 Design Criteria.

(1)

Table R301.2(1) (replace with): Table R301.2(1), Climatic and Geographic Design Criteria is included as an attachment to this Chapter.

Section R302 Fire-Resistant Construction.

(1)

R302.5.1 Opening protection. (replace with) 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 eighth (1 3/8) inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than one and three eighth (1 3/8) inches (35 mm) thick, or twenty-minute fire-rated doors.

(2)

R302.13 Fire protection of floors. (replace exceptions 3.1 and 3.2 with):

3.1 The aggregate area of the unprotected floor assembly does not exceed 100 square feet (9.3m²) per story.

3.2 Fireblocking in accordance with Section 302.11.1 is installed along the perimeter of the unprotected portion to separate the unprotected portion from the remainder of the floor assembly. 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.

Section R303 Light, Ventilation and Heating.

(1)

R303.3 (add text to end of exception) ", a gabled end with an approved termination cap, or a soffit with solid material extending three (3) feet in either direction of an approved termination cap."

Section R306.

(1)

R306.5 (add new section) Hose Bibb. Every dwelling shall provide one outside frost-proof hose bibb. The hose bibb shall be protected from backflow per Section P2902.

(2)

R306.6 (add new section) Floor Drain. All basements shall have a floor drain within twenty (20) feet of the heating/cooling systems(s) and water heaters. The floor drain shall comply with Chapter 27 of the International Residential Code for one and two family dwellings.

Section R311 Means of Egress.

(1)

R311.3.2 Floor elevations for other exterior doors. (replace exception with) Exception: A top landing is not required where a stairway of three (3) or fewer risers is located on the exterior side of the door, provided that door does not swing over the stairway.

(2)

R311.5.1 (Add new section) Exterior landing construction. Exterior landings shall be constructed of a hard surface. Level grass areas shall not qualify as an approved exterior landing surface.

(3)

R311.7.5 Stair treads and risers. (add exception):

Exception: For remodeling projects inside existing dwelling units where the surrounding framing of the stairwell (framed stairwell hole) is not reconfigured or relocated, or where new additional stairs are not being added to the structure, stair tread and riser dimensions are permitted to match previous or existing conditions.

(4)

R311.7.6 Landings for stairways. (replace exception with):

Exception: A floor or landing is not required at the top of an interior flight of stairs, or an exterior flight of stairs with three or fewer risers, including stairs in an enclosed garage, provided that a door does not swing over the stairs.

Section R313 Automatic Fire Sprinkler Systems.

(1)

R313.1 Townhouse automatic fire sprinkler systems. (replace with) An automatic residential fire sprinkler system shall be installed in townhouses, in accordance with Section 67.281 of the Missouri Revised Statutes.

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

(2)

R313.2 One- and two-family dwellings automatic fire systems. (replace with) A builder of a single-family dwelling or residence or multi-unit dwellings of four (4) or fewer units 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 single-family dwelling, residence, or multi-unit dwelling shall be denied the right to choose or decline to install a fire sprinkler system in such dwelling or residence being purchased by any code, ordinance, rule, regulation, order, or resolution by any county or other political subdivision. Any county or other political subdivision shall provide in any such code, ordinance, rule, regulation, order, or resolution the mandatory option for purchasers to have the right to choose and the requirement that builders offer to purchasers the option to purchase fire sprinklers in connection with the purchase of any single-family dwelling, residence, or multi-unit dwelling of four (4) or fewer units.

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 sprinkler system.

Chapter 4 Foundations.

Section R403 Footings.

(1)

R403.1.7 Footings on or adjacent to slopes. (replace with) 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 (thirty-three and three tenths percent (33.3%) slope) shall conform to Sections R403.1.7.1 through R403.1.7.4 or plans as signed and sealed by a structural engineer licensed by the State of Missouri.

Section R404 Foundation and Retaining Walls.

(1)

R404.1.3.2 Reinforcement for foundation walls. (add exception):

Exception: Where a licensed Missouri engineer's geotechnical report confirms that unstable soil or ground water conditions do not exist on an individual home site, concrete foundation walls may be constructed in accordance with Table R404.1.2(10).

(a)

Table R404.1.2(10) Concrete Foundation Walls (add table):

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 #4 reinforcing bars shall be placed horizontally in the top and bottom of the foundation wall. A minimum of two #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 #5 reinforcing bars shall be placed horizontally in the top, middle, and bottom of the foundation wall. A minimum of two #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 c: Concrete foundation walls may be constructed a minimum of nominal twelve (12) inches thick. A minimum of three #5 reinforcing bars shall be placed horizontally in the top, middle, and bottom of the foundation wall. A minimum of two #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.

Section R405 Foundation Drainage.

(1)

405.1 Concrete or masonry foundations. (number existing exception as number one + add second exception):

2.	Drains provided as detailed in Section R405.1.2 are approved as an alternative method to meet the requirements of this Section.

(2)

R405.1.2 (add new section) Soil evaluations. An evaluation of the soil by a geotechnical engineer 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.

(3)

R405.1.2.1 (add new section) 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.

(4)

R405.1.2.2 (add new section) 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.

(5)

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

(6)

R405.1.2.4 (add new section) 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.

Chapter 5 Floors.

Section R507 Exterior Decks.

(1)

R506.2.3 Vapor retarder. (replace), "10 mil (0.010 inch; 0.254 mm)" with "6 mil (0.006 inch; 0.152 mm)."

Chapter 9 Roof Assemblies.

Section R905 Requirements for Roof Coverings.

(1)

R905.2.8.2 Valleys. (replace number 3 with):

For closed valleys (valley covered with shingles), valley lining of two ply of .15 felt complying with D226 Type I, ASTM D4869 Type I, or ASTM D6757, or valley lining as described in Item 1 and 2 shall be permitted. Self-adhering polymer modified bitumen underlayment complying with ASTM D1970 shall be permitted in lieu of the lining material.

(2)

R905.2.8.5 Drip Edge. (add exception):

Exception: An alternative design approved as provided for in R104.11.

Chapter 10 Chimneys and Fireplaces.

Section R1004 Factory-Built Fireplaces.

Section R1005 Factory-Built Chimneys.

(1)

R1005.7 Factory-built chimney offsets. (add exception):

Exception: Chimneys installed per manufacturer's installation instructions.

Section R1006.

(1)

R1006.1.1 Factory-built fireplaces. (replace with) Exterior combustion air ducts for factory-built fireplaces shall be a listed component of the fireplace, or equivalent approved by the jurisdiction, and shall be installed according to the fireplace manufacturer's instructions.

(2)

R1006.2 (replace with) Exterior air intake. The exterior air intake on masonry fireplaces shall be capable of supplying combustion air from the exterior of the dwelling or from spaces within the dwelling ventilated with outdoor air such as nonmechanically ventilated crawl or attic spaces. The exterior air intake shall not be located within the garage or basement of the dwelling. The exterior air intake, for other than listed factory-built fireplaces, shall not be located at an elevation higher than the firebox. The exterior air intake shall be covered with a corrosion-resistant screen of 1/4-inch (6.4 mm) mesh.

Chapter 11 Energy Efficiency.

Section N1101 General.

(1)

N1101.6 (R202) Defined terms.

PROJECTION FACTOR. (add definition) 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.

N1101.4 (R102.1.1) Above code programs. (replace with) The building official or other authority having jurisdiction shall be permitted to deem a national, state or local energy-efficiency program to exceed the energy efficiency required by this code. Buildings approved in writing by such an energy-efficiency program shall be considered in compliance with this code. Applicant must provide adequate information to the Dardenne Prairie Building Official to demonstrate that the Above Code Program satisfies all necessary code requirements.

(2)

N1101.6 (R202) Defined terms.

Section N1102 (R402) Building Thermal Envelope.

(1)

Table N1102.1.2 (R402.1.2) (replace with): Table N1102.1.2 (R402.1.2), Insulation and Fenestration Requirements by Component, is included as an attachment to this chapter.

(2)

N1102.1.3 (R402.1.3) (replace with) 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 blown 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.

(3)

N1102.1.5 (R402.1.5) Total UA alternative. (replace with) 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. Jurisdiction will require a separate sealed submission for each proposed home to use shaded vertical fenestration. The projection 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 (+/- forty-five degrees (45°) or 0.79 rad) for purposes of calculations and demonstrating compliance.

(4)

Table N1102.1.5 (add table):

Minimum Projection Factor Required by Orientation for SHGC Exception
Orientation	Projection Factor
North	>=0.40^a
South	>=0.20
East	>=0.50
West	>=0.50

^a	For the north orientation, a vertical projection located on the west-edge of the fenestration with the equivalent of PF>=0.15 shall also satisfy the minimum projection factor requirement

(5)

N1102.2.4 (R402.2.4) Access hatches and doors. (replace with) Access doors from conditioned 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 requirements of Table R1102.1.2 based on the applicable climate zone specified in Chapter 3.

(6)

N1102.4 (R402.4) Air leakage (replace with) 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.

(7)

Table N1102.4.1.1 (402.4.1.1)(replace with):

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.

(8)

N1102.4.1.2 (R402.4.1.2) (replace with) Testing Option. If testing is elected, the building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding five (5) air changes per hour in Climate Zone 4. Testing shall be conducted in accordance with ASTM E 779 or ASTM E 1827 and reported at a pressure of two tenths (0.2) inches 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.

(9)

N1102.4.5 (R402.4.5) Recessed lighting. (replace with) Recessed luminaires installed in the building thermal envelope may be sealed to limit air leakage between conditioned and unconditioned spaces. All recessed luminaires may be IC-rated and labeled as having an air leakage rate not more than 2.0 cfm (0.944 L/s) when tested in accordance with ASTM E 283 at a 1.57 psf (75 Pa) pressure differential. All recessed luminaires may be sealed with a gasket or caulk between the housing and interior wall or ceiling covering.

Section N1103 (R403) Systems.

(1)

N1103.1.1 (R403.1.1) Programmable thermostat. (delete section).

(2)

N1103.3.2 (R403.3.2) Sealing. (replace with) Ducts, air handlers and filter boxes shall be sealed. Joints and seams shall comply with either the International Mechanical Code or Section M1601.4.1 of this code, as applicable.

Exceptions:

1.	Air-impermeable spray foam products shall be permitted to be applied without additional joint seals.
2.	Continuously welded and locking-type longitudinal joints and seams in ducts operating at static pressure less than two (2) inches of water column (500 Pa) pressure classification shall not require additional closure systems.

(3)

N1103.3.3 (R403.3.3) Duct testing (Mandatory). (delete section).

(4)

N1103.3.5 (R403.3.5) Building cavities (Mandatory). (delete section).

(5)

N1103.4.1 (R403.4.1) Protection of piping insulation. (replace with) 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 which otherwise meets the requirements of this Section shall be permitted.

(6)

N1103.5.2 (R405.5.2) Hot water pipe insulation. (replace #1 with) 1. Metallic piping larger than or equal to three fourths (3/4) inch (19mm) in normal diameter.

(7)

N1103.5.3 (R405.5.3) Hot water pipe insulation (Prescriptive). (replace with) Insulation for hot water pipe with a minimum thermal resistance (R-value) of R-3 shall be applied to the following:

1.	Metallic piping larger than or equal to 3/4 inch (19 mm) nominal diameter.
2.	Piping serving more than one 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.

(8)

N1103.6 (R403.6) Mechanical ventilation. (replace with) If, in accordance with previous code sections or as part of an Above Code Program, the resulting air changes per hour (ACH) at 50 Pascals is 3 air changes or less, 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.

(9)

N1103.7 (R403.7) Equipment sizing and efficiency rating (Mandatory). (replace with) Equipment sizing and efficiency rating (mandatory). Heating and cooling equipment shall be sized in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies. New or replacement heating and cooling equipment shall have an efficiency rating equal to or greater than the minimum required by Federal law for the geographic location where the equipment is installed.

Section N1104 (R404) (delete section).

Section N1105 (R405) Total Building Performance.

(1)

Table N1105.5.2(1) [R405.5.2(1)] (replace with):

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
Foundations	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 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) SHGC = 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 5 air changes per hour in Climate Zones 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 = conditioned floor area N_br = number of bedrooms Energy recovery shall not be assumed for mechanical ventilation Air leakage rate of 5 air changes per hour in at a pressure of 0.2	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^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 = conditioned 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, eighty percent (80%) of floor area covered by R-2 carpet and pad, and twenty percent (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 Nonelectric Furnaces: natural gas furnace with prevailing Federal minimum standards Nonelectric 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 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 26.24 and the "Whole-house Ventilation" provisions 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 fifteen degrees (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 nonstorage-type water heater, a 40-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 40-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.

Chapter 13 General Mechanical System Requirements.

Section M1301 General.

(1)

M1301.2 Identification. (add exception):.

Exception: Line sets and similar materials provided the installer can provide documentation related to the material used such as, but not limited to, a receipt, invoice, or container

Section M1305 Appliance Access.

(1)

M1305.1.3.1 Ground clearance. (replace with) 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.

(2)

M1305.1.3.3 Electrical Requirements. (add exception):

Exception: Basements

Chapter 15 Exhaust Systems.

Section M1502 Clothes Dryer Exhaust.

(1)

M1502.4.1 Material and size. (replace with) Exhaust ducts shall have a smooth interior finish and be constructed of metal having a minimum thickness of 0.0157 inch (0.3950 mm) (No. 30 gage). The duct shall be four (4) inches (102 mm) nominal in diameter.

(2)

M1502.4.2 Duct Installation. (replace with) 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 and shall be mechanically fastened or fastened by other methods as approved by the Authority Having Jurisdiction. Ducts shall not be joined with screws or similar fasteners that protrude more than one eighth (1/8) inch (3.2 mm) into the inside of the duct.

(3)

M1502.4.3 Transition duct. (add language to end of existing section) "Flexible duct that is listed and labeled for the intendent purpose may be used as the transition duct."

(4)

M1502.4.5 Booster fans prohibited. (add exception).

Exception: Booster fans may be permitted when a signed and sealed engineered design is provided.

Section M1503 Domestic Cooking Exhaust Equipment.

(1)

M1503.6 Makeup air required. (replace with) Exhaust hood systems capable of exhausting in excess of four hundred (600) cubic feet per minute (0.19 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. Dampers 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. Such makeup air systems shall be equipped with a means of closure and shall be automatically controlled to start and operate simultaneously with the exhaust system.

Section M1601 Duct Systems.

(1)

M1601.1.1 Above-ground duct systems. (replace number 2 with):

2.	Factory-made ducts shall be listed and labeled in accordance with UL 181 and installed in accordance with the manufacturer's instructions.

(2)

M1601.4.1 Joints, seams and connections. (replace with):

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 181A-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 UL 181B 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 fittings shall be mechanically fastened. Mechanical fasteners for use with flexible nonmetallic 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 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 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 seams in ducts operating at static pressure less than two (2) inches of water column (500 Pa) pressure classification shall not require additional closure systems.

10.

Chapter 21 Hydronic Piping.

Section 2101.

(1)

M2101.22.6 Expansion tanks. (delete).

(2)

M2101.26 Pipe penetrations. (replace with) 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.

Section G2105 Ground-Source Heat-Pump System Loop Piping.

(1)

M2105.4 Piping and tubing materials standards. (replace with) Piping and tubing materials standards. Ground-source heat-pump ground-loop pipe and tubing shall conform to the standards listed in Table M2105.4. However, polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) shall not be used for geothermal application inside or underground.

11.

Chapter 24 Fuel Gas.

Section G2408 Installation.

(1)

G2408.4 (305.7) Clearances from grade. (replace with) 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.

12.

Chapter 36 Services.

Section E3601 General Services.

(1)

E3601.8 Emergency disconnects. (delete).

(2)

E3606.5 Surge protection. (delete).

13.

Chapter 39 Power and Lighting Distribution.

Section E902 Ground-Fault and Arc-Fault Circuit-Interrupter Protection.

(1)

E3902.6 Kitchen receptacles. (add exception):

When a simplex/single receptacle is installed for fastened in place appliances or outlets designated for refrigerators/freezers.

(2)

E3902.11 Kitchen dishwasher branch circuit. (add exception):

Exception: When on a dedicated circuit and a simplex/singe receptacle is installed.

(3)

E3902.18 Location of ground-fault circuit interrupters. (replace with) Location of ground-fault circuit interrupters. Ground-fault circuit interrupters shall be installed only in a readily accessible location. [210.8(A)]

(4)

E3902.20 Arc-fault circuit interrupter protection. Arc-fault circuit interrupter protection. (replace first paragraph) Branch circuits that supply 120-volt, single phase, 15 and 20 ampere outlets installed in bedrooms, and any branch circuit that has in-part or in-whole aluminum wiring shall be protected by any of the following: [210.12(A)]