City of Nashua, NH Article III Base Districts

§ 190-14 Purpose statements.

The purpose and intent of the base zoning districts are as follows:

Table 14-1 Zoning District Purpose Statements
District	Purpose
Rural Residence (R-40)	The Rural Residential District has a minimum lot size requirement of 40,000 square feet (or approximately one acre). This district is reserved primarily for the southwest quadrant of the City and other areas with limited infrastructure capacity and environmental or topographical restrictions. The R-40 District is also the primary district where individual wells and septic systems are in use, although sewer and water extensions have been made to some parts of the district.
A Suburban Residence (R-30)	The R-30 District is similar to R-40, with a slightly smaller minimum lot size of 30,000 square feet. Most of the R-30 Districts provide a buffer between the R-40 District and suburban areas, such as the southwest quadrant and the northwest quadrant near the Hollis border west of the airport.
B Suburban Residence (R-18)	These districts are more evenly distributed throughout the City, although the majority of the R-18 and R-9 land is found in the southwest quadrant. This district provides suburban densities and intensities for primarily residential neighborhoods, with conservation subdivisions permitted as an option in order to encourage the preservation of natural resources.
C Suburban Residence (R-9)	These districts are more evenly distributed throughout the City, although the majority of the R-18 and R-9 land is found in the southwest quadrant. This district provides suburban densities and intensities for primarily residential neighborhoods, with conservation subdivisions permitted as an option in order to encourage the preservation of natural resources.
A Urban Residence (R-A)	This district is appropriate for the older residential sections of Nashua surrounding the urban core. R-A is predominantly single family, although duplexes are allowed subject to special standards.
B Urban Residence (R-B)	This district is appropriate for the older residential sections of Nashua surrounding the urban core. The R-B District permits duplexes by right and multifamily dwellings with three or more units subject to special standards.
C Urban Residence (R-C)	This district is appropriate for the more well-established residential sections of Nashua that include areas immediately surrounding the urban core and neighborhoods throughout the urban area. The R-C District permits all residential types by right, provided all dimensional requirements are met.
Local Business (LB)	Local Business (LB) Districts are commercial areas primarily located adjacent to or within established residential neighborhoods. They are intended as convenience commercial districts that support adjacent neighborhoods. The LB District is pedestrian-oriented as opposed to automobile-oriented.
Highway Business (HB)	Highway Business (HB) Districts are commercial areas located primarily adjacent to heavily traveled arterial roads, such as Amherst Street and the Daniel Webster Highway.
General Business (GB)	General Business (GB) Districts are similar to the HB Districts in purpose, function, and appearance, but require a smaller minimum lot size. The GB Districts are generally found in close proximity to the HB Districts, but tend to be developed as shopping centers with large parking areas (including the malls), rather than for "strip" commercial development, which characterizes development in the HB Districts.
Downtown (D-1 and D-3)	The D Districts consist of the downtown and the surrounding business area. These are mixed-used districts, which permit some apartment and multifamily uses as well as commercial and institutional uses. The D Districts are pedestrian-oriented as opposed to automobile-oriented. These districts include many of Nashua's historic structures.
Park Industrial (PI)	The Park Industrial (PI) Districts are industrial areas that, for the most part, abut the major turnpike interchanges, and are adjacent to residential zones. The PI District provides locations for light industry and industrial parks. This district implements the Master Plan recommendation to provide adequate zoning for industrial park-type development.
General Industrial (GI) [Amended 2-26-2008 by Ord. No. O-08-07]	The General Industrial (GI) Districts are the older, traditional industrial areas of the inner City. They are often in close proximity to the Nashua or Merrimack Rivers and are generally accessible by railroad and/or local roads. Most of Nashua's heavy industries are located in the GI Districts. This district implements the Master Plan recommendation to provide a reasonable amount of space for heavy industrial uses, provided they are environmentally sound and do not detract from neighboring land uses.
Airport Industrial (AI)	This district includes the Boire Field Airport and the surrounding industrially zoned land. It supports the airport's operations by providing an area for airport-related and airport-compatible uses.

§ 190-15 Permitted uses.

[Amended 1-22-2019 by Ord. No. O-18-033; 4-26-2022 by Ord. No. O-22-010; 8-12-2025 by Ord. No. O-25-055]

Purpose: Pursuant to RSA 674:16, this section regulates the location and use of buildings, structures and land used for business, industrial, residential, or other purposes. This section implements the following Master Plan recommendations:
•	Update the commercial land-use definitions in the Nashua Revised Zoning Ordinances.
•	Write clear definitions of all potential industrial types/uses and apply them to all of the Industrial Zones.

A. Applicability. Except as provided in this article, no building, structure or land shall be used except for the purposes permitted in the district as described in this article.

B. Mixed uses. In cases of mixed occupancy, the regulation for each use shall apply, as provided in this Part 2, to that portion of the building or land.

C. Use Matrix.

(1) The uses permitted in each zoning district are set forth in Table 15-1 below. Any use not listed is prohibited, unless the Administrative Officer determines that it falls within the same class as a listed use as set forth in Subsection D below.

(a) Uses permitted by right are uses designated by a "P" in Table 15-1.

(b) Conditional uses are designated by a "C" in Table 15-1 and require a permit from the Planning Board as set forth in § 190-133 of the Land Use Code.

(c) Uses that require a special exception are designated by an "S" in Table 15-1 and require review by the Zoning Board of Adjustment as set forth in § 190-134 of the Land Use Code.

(d) Accessory uses are defined by Article XLII, Definitions, and are designated by an "A" in Table 15-1.

(2) Uses permitted by right or by conditional use shall be subject, in addition to use regulations, to all other provisions of this article.

D. Interpretation of Table 15-1.

(1) Uses not listed as a permitted or conditional use are presumed to be prohibited from the applicable zoning district. In the event that a particular use is not listed in the Use Matrix, and such use is not listed as a prohibited use and is not otherwise prohibited by law, the Administrative Officer shall determine whether a materially similar use exists in this section. Should the Administrative Officer determine that a materially similar use does exist, the regulations governing that use shall apply to the particular use not listed, and the Administrative Officer's decision shall be recorded in writing. Should the Administrative Officer determine that a materially similar use does not exist, this chapter may be amended to establish a specific listing for the use in question.

(2) The Administrative Officer may determine that a use is materially similar if:

(a) The use is listed as within the same structure or function classification as the use specifically enumerated in the Use Matrix, as determined by the Land-Based Classification Standards (LBCS) of the American Planning Association [Reference: http://www.planning.org/Ibcs/index.html]. The use shall be considered materially similar if it falls within the same LBCS classification and meets the requirements of Subsections D(2)(b) and (c) below.

(b) If the use cannot be located within one of the LBCS classifications pursuant to Subsection D(2)(a) above, the Administrative Officer shall refer to the North American Industry Classification Manual (NAICS) [Executive Office of the President, Office of Management and Budget, 1997]. The use shall be considered materially similar if it falls within the same industry classification of the NAICS, and meets the requirements of Subsection D(2)(c) below. [Reference: http://www.census.gov/epcd/www/naics.html]

(c) The proposed use shall not generate average daily trips exceeding other uses proposed in the zoning district by more than 10%, as determined by the Institute of Transportation Engineers, Trip Generation (6th ed., 1997) [the "ITE Manual"], which document is hereby incorporated by this reference. If the trip generation is not listed in the ITE Manual, the use shall be considered materially similar. The Administrative Officer may also refer to similar local traffic studies.

(3) In order to assist in interpretation of the Use Matrix, the LBCS and NAICS numbers precede each use in the Use Matrix. In interpreting the Use Matrix, the following rules of construction shall apply:

(a) If a use is listed for a specific classification, while a more general classification within the same industry classification is also listed for another use, the specific classification governs. The specific use is not permitted in all districts where the uses coded to the general classification are permitted simply because they share a similar LBCS or NAICS code number. The numbers increase as the classifications get more specific.

(b) Some uses are listed separately, but fall within the same LBCS or NAICS classification. The uses within one such classification are not permitted in all of the zoning districts as the others simply because they fall within the same LBCS or NAICS classification.

(4) Commercial uses designated with the superscript "1" (¹) are permitted only as part of a site plan in which at least 75% of the gross floor area is reserved for uses listed in the "industrial and manufacturing" category.

(5) Self-storage facilities designated with the superscript "2" (²) must be at least 200 feet from the City right-of-way; and all storage bay doors to be screened from view from all adjacent street frontages and residentially used properties; and a minimum landscape buffer of 40 feet is required from all adjacent residentially used properties. The Planning Board may waive the 200-foot setback on nonarterial rights-of-way, door screening and forty-foot buffer as part of a conditional use application and site plan application, provided that it finds there are no negative impacts on the abutter, neighborhood or the City in addition to the required criteria for waivers (§ 190-148D).

(6) Facilities with a primary use designated with the superscript "3" (³) shall be a minimum of 1,000 feet from like-classified uses and 1,000 feet from schools or youth-serving organizations. The Planning Board may waive the 1,000-foot measurement, provided that the applicant demonstrates that there are no negative impacts on the direct abutters, neighborhood, or City and that the project meets the required criteria for waivers (§ 190-148D). The Planning Board may not waive the 1,000-foot measurement if the facility directly abuts a school or youth-serving organization. For the purposes of this section, schools and youth-serving organizations are defined as organizations with a physical location whose primary purpose is to serve persons under the age of 18. Examples could include schools, childcares, camps, or organizations whose primary purpose is youth support and development which offer on-site programming, including housing, for persons under the age of 18.

(7) Facilities with a primary use designated with the superscript "4" (⁴) shall be required to apply for a Conditional Use Permit (CUP) permit where located within the General Industrial (GI) zone and overlain by a Transit-Oriented Development overlay district.

(8) Facilities with a primary use designated with the superscript "5" (⁵) shall not be permitted in General Industrial (GI) zones which are overlain by a Transit-Oriented Development (TOD) overlay district

§ 190-16 Dimensional regulations.

[Amended 6-10-2025 by Ord. No. O-24-042]

Purpose: Pursuant to RSA 674:16, this section regulates the location and use of buildings, structures and land used for business, industrial, residential, or other purposes. This section implements the following Master Plan recommendations:
•	Encourage infill development within, and work to revitalize existing commercial areas.
•	Guide commercial and industrial development to the existing built areas of the City and minimize development in outlying, undeveloped areas.
The dimensional regulations are found in Table 16-3 of this section.

A. Applicability.

(1) This section establishes minimum and maximum standards for the height, number of stories and size of buildings and other structures, the percentage of lots that may be occupied, the size of yards, courts and other open spaces, the density of population, and the location and use of buildings pursuant to RSA 674:16. Developments subject to the supplemental use regulations (Article VI) may be governed by their respective sections in this chapter and, if so indicated in the specific supplemental use regulation, may be exempt from the dimensional and density regulations of this § 190-16 or Table 16-3.

(2) No land or building shall hereafter be used or occupied and no building or part thereof shall hereafter be constructed, erected, altered or moved unless in conformity with all of the regulations herein specified for the zoning district in which it is or will be located. No building permit shall be issued unless the proposed building or structure conforms to the standards established in this section.

Comment: For utility structures, see Part 6.

B. Residential density (Dimensional Matrix, Column B).

(1) Density restrictions apply only to conservation subdivisions and to dwelling units other than single-family detached dwellings. No building, structure or land shall hereafter be used or occupied in excess of the prescribed density regulations, nor accommodate a greater number of dwelling units than prescribed for in the zoning district in which it is or will be located.

(2) In computing density for large tracts or multiunit housing projects, the density limits established by the zoning district apply. Densities may exceed the maximum on part of a tract, if the overall density on the total project site does not exceed the limits established by the zoning district.

Comment: For single-family detached dwellings not in conservation subdivisions, no maximum number of total permitted dwelling units is established because the total number of dwelling units is governed by minimum lot size. Conservation subdivisions are not subject to minimum lot size, but total permitted dwelling units shall not exceed the density established as set forth in Table 16-3.

(3) No household other than a family shall have a number of members exceeding the figure provided in Table 16-1 below entitled "Occupancy Restrictions":

Table 16-1 Occupancy Restrictions
Dwelling Type	Maximum Number of Occupants in Unrelated Household Per 300 Square Feet of Habitable Floor Area
Single-family dwelling	0.6
Duplex or townhouse	1
Apartment, including accessory apartments	1.5
Bed-and-breakfast	3
Rooming/boarding, including accessory rooming/boarding	2
Dormitory	3
Fraternity or sorority	2
Nursing home	2
Elderly housing	1.5

(a) All single-family residential dwelling units of 2,000 square feet of habitable floor area or less are permitted a base occupancy of four unrelated individuals. For single-family dwellings larger than 2,000 square feet, the base occupancy remains four unrelated individuals, with additional unrelated occupants allowed at the ratio specified in Table 16-1, applied to the habitable floor area exceeding 2,000 square feet.

C. Minimum lot area (Dimensional Matrix, Column C).

(1) Applicability. The lot or yard areas required for any new building or use may not include any part of a lot required by any other building or use to comply with any provision of this article, nor may these areas include any property of which the ownership has been transferred subsequent to the effective date of this article if such property was a part of the area required for compliance with the dimensional regulations applicable to the lot from which such transfer was made. Lots shall not be so separated or transferred in ownership so as not to comply with this article. No permit for development shall be issued for a lot that does not meet the minimum lot area requirements of Table 16-3 of this chapter except for nonconforming lots of record.

(2) Nonconforming lots of record. See § 190-121.

D. Floor area ratio/intensity in nonresidential districts (Dimensional Matrix, Column O). Unless otherwise stated, all references to nonresidential intensity shall be deemed to refer to floor area ratio (FAR). FAR is computed as the ratio of gross floor area of all buildings and structures to the total lot area.

E. Setbacks (Dimensional Matrix, Columns G through K).

(1) Applicability and rules of interpretation. Setbacks for buildings or structures are measured as the area between the furthest projection of a principal structure and the property line of the lot on which the structure is located, except as provided below. Where a yard abuts a street, the setback shall be measured from the abutting street right-of-way line.

Commentary: Typically, the side and rear setback is measured from the property line, while the front setback is measured from the right-of-way because the front yard adjoins the street.

(2) Development in setbacks.

(a) Setbacks shall be unobstructed from the ground to the sky except as specified in this section. The following features may encroach into a required building setback:

[1] Any buttress, cornice or pier may extend beyond the setback not more than 12 inches.

[2] Unenclosed steps not extending above the first floor level may extend up to three feet to a side property line or up to a front property line.

[3] Retaining walls, regardless of necessary height, may extend up to 18 inches to a street line or service lane.

[4] A protective hood or overhang over a doorway may extend not more than three feet into the required minimum yards.

[5] Balconies or bay windows, not to exceed three feet into the required setback.

[6] Chimneys, not to exceed two feet.

[7] Heating and cooling units, not to exceed three feet.

[8] Overhanging roof, eave, gutter, cornice, or other architectural features and awnings, not to exceed two feet.

[9] Unenclosed decks, terraces, stoops or porches, provided that:

[a] Such structures shall not exceed four feet in height; and

[b] Such structures shall not be located closer than five feet to any property line.

[10] Fences or shrubs.

[11] Steps or stoops over four feet in height, windowsills, chimneys, roof eaves, structural overhangs or projections enclosing habitable living space, or similar architectural features which may project not more than two feet.

[12] Projecting overhangs on the ground floor not listed above may extend:

[a] Up to 30 inches beyond the front setback; and

[b] Beyond the side setback up to 20% of the side yard.

[13] Fire escapes, fire towers, storm enclosures, or handicap ramps where required by the Building Code.[1]

[1] Editor's Note: See Ch. 105, Building Construction.

[14] Any accessory building or use customarily incidental to the permitted principal use or building as allowed in accordance with § 190-31, Accessory uses and structures.

(b) Whenever more than one principal building is to be located on a lot, the required yards shall be maintained around the group of buildings. Buildings shall be separated by any distance prescribed by the Fire Code. (See Chapter 156 of the City Code).

(3) Special exceptions for minor encroachments.

Purpose: This subsection provides a streamlined review process for applicants proposing minor encroachments into required setback areas. The purpose is to reconcile the legitimate objectives of homeowners requesting minor expansions of existing dwellings, with the objectives of surrounding neighborhoods to protect their character, appearance, and safety. Accordingly, this subsection provides an inexpensive, streamlined review process, while allowing concerned neighbors to comment where the expansion will have a measurable impact.

(a) For purposes of this subsection, the extension of a building, structure, or paved surface not exempted by Subsection E(2) above, into a setback by a distance not exceeding the amounts prescribed in Table 16-2 shall be considered a "minor encroachment" and may be approved as a special exception (See § 190-134.) by the Zoning Board of Adjustment (ZBA) on a consent agenda. Nothing in this section shall be construed in such a manner as to eliminate the applicant's burden of proving that the encroachment meets the criteria for approval of a special exception. The application for a special exception considered on the ZBA's consent agenda shall include a monumented survey. If the applicant chooses not to submit a monumented survey, the case shall be considered as part of the ZBA's normal hearing process. The application, including a monumented survey, shall be considered part of the evidence in the proceeding unless it is excluded by the ZBA following an objection stated on the record. This subsection does not apply to an application for subdivision plan approval.

Table 16-2 Minor Encroachments
Zoning District	Front Yard Encroachment (feet)	Side Yard Encroachment (feet)	Rear Yard Encroachment (feet)
R-40	6	5	16
R-30	6	5	11
R-18	6	5	11
R-9	6	4	10
R-A	6	4	9
R-B	6	4	6
R-C	4	4	3

F. Front setbacks.

(1) Adjustment for infill lots. The Administrative Officer may approve the reduction of a district's setback requirement for the development of infill lots, where it can be shown that the proposed setback is consistent with the average setback that exists in the neighborhood. The applicant shall provide to the Administrative Officer a map showing the adjoining lots within 200 feet of the subject lot, noting what the existing setbacks are on those properties.

(2) Buildings facing away from street. Where a principal use building or structure is oriented to face away from the street on which it fronts, said building or structure shall conform to the required front yard setback for the district in which it is located. Any accessory use(s) prohibited from required front yards within such districts are prohibited within the required front yard setback from a principal use building or structure facing away from the street.

(3) Front setbacks. Where a frontage is divided among districts with different front yard requirements, the deepest front yard applies to the entire frontage. However, the front setback may be adjusted as provided in Subsection F(1) above.

(4) Development in front yard. No structure other than a driveway, sign, fence, gate, sidewalk, berm or other landscape feature shall be erected or permitted to be located in a required front yard area.

G. Side setbacks. Side setbacks shall be measured from the side property line. (See special rules for corner lots in Subsection J below.)

H. Rear setbacks. Rear setbacks shall be measured from the rear property line.

I. Height of buildings and/or structures.

(1) Height shall be measured as provided in Chapter 5 of the International Building Code.

(2) Height limitations.

(a) The height limitations of this chapter shall not apply to any of the following structures not intended for human occupancy:

	Antennas
	Beacons
	Belfries
	Chimney flues
	Chimneys
	Clock towers
	Cupolas
	Domes
	Electrical, mechanical, or elevator
	Monuments
	Parapet walls as needed to screen equipment
	Radio aerials
	Smokestacks
	Spires
	Steeples
	Structures for essential services
	Television antennas (subject to § 190-38)
	Transmission towers (subject to § 190-38)
	Windmills

(b) Height limits shall not apply to any bulkhead, elevator, water tank, or to any similar structure or necessary mechanical appurtenance extending above the roof of any building if such structure does not occupy more than 33% of the area of the roof.

(3) In Park Industrial (PI), Transit-Oriented Development (TOD) and Highway Business (HB) Zones, the maximum height permitted is increased to 120 feet and the maximum number of stories permitted is increased to eight, where the building is at least 400 feet from the nearest R-B or R-C Zone, and at least 1,000 feet from the nearest R-A, R-9, R-18, R-30, or R-40 Zone.

J. Corner lots or through lots. Corner lots and through lots shall be considered to have a front yard bordering on each street line, and a side yard opposite each front yard. Where a lot fronts on two nonintersecting streets, or two intersecting streets forming an angle of 60° or less, front yards shall be provided on both streets.

K. Sight triangle.

(1) For purposes of this subsection, "sight triangle area" means the portion of a corner lot lying within a triangle area formed by measuring from the vertex of that portion of the property line adjacent to the intersecting street, to a point on each property line running from the vertex equal to 20 feet in residential zoning districts and five feet in nonresidential zoning districts, and then connecting the two points thus established with a third line.

(2) No planting, wall, fence, sign, or other obstruction to motorists' vision shall be planted, erected or maintained higher than the following distance above the adjoining street grade within a sight triangle area:

(a) Curbed streets: one foot.

(b) Uncurbed streets: 1 1/2 feet.

L. Cul-de-sac lots. In the case of lots which have the entire frontage on the bulb of a cul-de-sac, the minimum frontage may be reduced to 50 feet, provided that the required minimum frontage dimension for the applicable district is observed as the minimum lot width at the required front yard setback.

M. Open space percentage. "Open space" means the space on a lot unoccupied by buildings, unobstructed to the sky by man-made objects, not devoted to streets, driveways, off-street parking or loading spaces. The open space percentage (Column (N) of Table 16-3, below) refers to the minimum open space area expressed as a percentage of total lot area.

§ 190-17 Residential Districts (R-40, R-30, R-18, R-9, R-A, R-B, R-C).

Purpose: These districts implement the following Master Plan recommendations:
•	Protect the character of existing neighborhoods through zoning regulation and enforcement.

A. No application for development approval in the R-40, R-30, R-18, R-9, R-A, R-B, R-C Zoning Districts or residential uses in other districts shall be approved unless the proposed use and/or development conforms to the requirements of this article and a building permit is issued in accordance with Part 3. If subdivision and site plan approval are required the proposed development shall comply with the requirements of Parts 4 through 8.

[Amended 3-9-2021 by Ord. No. O-21-048]

B. Only one principal structure shall be permitted on a lot, except where otherwise provided by this chapter.

C. All proposed uses shall comply with the sign regulations (Article X) regardless of whether a site plan is required.

[Amended 3-9-2021 by Ord. No. O-21-048]

D. Specific residential district criteria. The following standards apply to all residential districts: All two-family dwellings (duplexes) shall be structures consisting either of two separate dwelling units on separate floors or of two separate dwelling units connected and separated by a common wall connecting living spaces, perpendicular to the longest dimension of the structure, and having a common length equal to at least: (i) 90% of the widest part of each structure measured perpendicular to the longest dimension, if the longest dimensions are parallel; or (ii) 90% of the widest part of one unit measured perpendicular to the longest dimension, and 50% of the longest dimension of the other unit, if the longest dimensions are perpendicular to each other.

[Added 2-27-2007 by Ord. No. O-06-51]

E. Driveways for residential uses shall be subject to the following provisions:

[Added 3-9-2021 by Ord. No. O-21-048]

(1) Driveways where they meet the public right-of-way and continuing to the rear line of the front yard setback shall be no more than 24 feet in width. Such width may be divided between two approaches to the right-of-way but no more than two. “Width” shall be measured along a line generally perpendicular to the line of intended vehicular travel.

(2) Driveways shall be located a minimum of 50 feet from an intersection.

(3) Driveways crossing a sidewalk shall maintain and continue the sidewalk width and cross slope (2% maximum). Sidewalk approaches shall be reconstructed in kind as necessary to make smooth transitions to the driveway crossing. Sidewalk width and grades at driveway crossings shall comply with ADA standards.

(4) Driveway approach angle. The angle of the driveway approach shall be approximately 90° for two-way driveways and between 60° and 90° for one-way driveways.

(5) Driveways shall be paved within the right of way and constructed per Division of Public Works standards, including permitting and inspection requirements.

§ 190-18 Commercial Districts (LB, GB, HB).

A. Specific LB District criteria.

(1) The following criteria shall be used (in addition to the general rezoning guidelines in § 190-132) in consideration of the placement of this district and the type and arrangement of uses within it.

(a) Refuse enclosures within an LB District shall be located at the rear of the site and screened with a wall and gate.

B. Specific GB and HB District criteria. The following standards apply to the GB and HB Zoning Districts:

(1) The following criteria shall be used (in addition to the general rezoning guidelines in § 190-132) in consideration of the placement of this district and the type and arrangement of uses within it:

(a) The district and its uses shall continue the orderly development and concentration of business and commercial uses; and

(b) Pedestrian and vehicular conflicts shall be minimized by an existing system of sidewalks and other pedestrian amenities which provide connectivity to surrounding neighborhoods, while providing adequate separation and channeling of pedestrian and vehicular movements; and

(c) GB and HB Districts shall be located along arterials and arterial/arterial or arterial/collector intersections.

(2) Outdoor display, storage and sales of merchandise is authorized subject to §§ 190-52 and 190-53.

§ 190-19 Industrial Districts (PI, AI, GI).

Purpose: This section implements the following Master Plan recommendations:
•	Provide a reasonable amount of space for heavy industrial uses, provided they are environmentally sound and do not detract from neighboring land uses.
•	Provide adequate zoning for industrial park-type development.
•	Discourage or prohibit noxious industries that create the potential for serious health or safety hazards.
•	Encourage attractive, landscaped, and sensitively sited industrial development that is compatible with surrounding land uses.

A. Specific PI and AI District criteria. The following standards apply to the PI and AI Zoning Districts:

(1) Location criteria. The following criteria shall be used (in addition to the general rezoning guidelines in § 190-132) in consideration of the placement of this district and the type and arrangement of uses within it:

(a) The district and its uses shall continue the orderly development and concentration of industrial and manufacturing uses; and

(b) The land area shall be sufficient to maintain compatibility with surrounding uses; and

(c) All lots within a PI District shall have direct access to arterial and/or collector streets.

(2) Commercial uses. See § 190-15D(4).

Comment: In § 190-15, commercial uses designated with the superscript "1" are permitted only as part of a site plan in which at least 75% of the gross floor area is reserved for uses listed in the industrial and manufacturing category.

(3) Additional site and building design criteria.

(a) In addition to the dimensional standards of § 190-16, no buildings or other structures, including parking lots, shall be erected closer than 30 feet to any property line abutting any area developed or zoned as a residential zoning district.

(b) All loading shall be from the rear or side of the building, but not facing a public street.

(c) Sidewalks consistent with the street improvement standards shall link all principal buildings, or shall link the principal building or buildings to off-site destinations, including retail, shopping, or services (including day care, dry cleaners or grocery stores).

(d) All noises, vibrations, emissions of smoke, dust, or gases shall be controlled so as not to be detrimental or cause a nuisance to nearby residential or commercial areas in conformance with the industrial performance standards of this chapter.

(e) Applicants are encouraged to provide the following site plan elements in order to create an office complex ambiance and appearance to the industrial development:

[1] Loading courts which are not visible from any public street. Screening of these areas shall be provided by the principal building; and

[2] Entry courts and pedestrian plazas; and

[3] Unique landscape features such as berming, fountains, and sculpture gardens, particularly adjacent to the arterial street; and

[4] Covered or decked parking structures which appear as an integrated part of the industrial building; and

[5] Parking areas located to the rear of the principal buildings or structures.

B. Specific GI District criteria. The following standards apply to the GI Zoning District:

(1) Location criteria. The following criteria shall be used (in addition to the general rezoning criteria established in § 190-132) in consideration of the placement of this district and the type and arrangement of uses within it:

(a) The district and its uses shall continue the orderly development and concentration of industrial and manufacturing uses; and

(b) The land area shall be sufficient to maintain compatibility with surrounding uses; and

(c) GI Districts shall have direct access to arterials and/or major collector streets. GI Districts shall not have direct access to a local street. Secondary or emergency access may be from a local street.

(2) Additional site and building design criteria.

(a) All driveways, parking areas, and pedestrianways shall be surfaced with an all-weather surface. Curbing shall be provided where required by the street design and transportation standards (Article XXX).

(b) All delivery and freight-handling areas shall be screened from view so as not to be visible from the boundary of any property not zoned GI or from the public right-of-way.

§ 190-20 Downtown Districts (D-1 and D-3).

Purpose: The Downtown Districts are established:
•	To promote the goals, objectives and strategies adopted as part of the City's Master Plan and the Downtown Master Plan.
•	To protect the value and efficiency of operation of surrounding properties.
•	To maintain unique aesthetic, architectural and visual amenities of individual buildings or cluster of buildings.
•	To enable infill development to occur in a manner that is compatible with the surrounding site environment and neighborhood.
•	To ensure that private development and rehabilitation are compatible and coordinated with public investment and improvements.
•	To support new construction and adaptive reuse of buildings through appropriate engineering, architectural and design solutions.
•	To guide the orderly and timely transition from one land use to another within areas subject to building obsolescence, changes in technology, environmental conditions and adjoining development patterns and influences.
•	To ensure that redevelopment occurring in close proximity to the Nashua and/or Merrimack Rivers will conserve and incorporate natural features and enable both visual and physical riverfront access.
•	To promote development opportunities that will eliminate blight and disinvestment.
•	To introduce uses that will have positive long-term social and economic impacts.
•	To establish a complimentary and integrated working, shopping and living environment.
This section implements the following Master Plan recommendations:
•	Develop unified facade and signage standards for commercial buildings in the downtown.
•	Guide commercial and industrial development to the existing built areas of the City and minimize development in outlying, undeveloped areas.
•	Encourage and support businesses that reduce employee and product-related vehicle trips.
In accordance with the Downtown Master Plan, this section establishes two downtown districts. D-1 is the traditional downtown core. It permits more intensive development coupled with pedestrian-friendly design standards. D-3 is a predominantly commercial area, with a more human scale and pedestrian-friendly design standards.
The illustrations throughout this section serve as a guide and are not regulatory.

A. Generally.

(1) Applicability. This Subsection A applies to any lot or parcel within a D-1 or D-3 District. Any site plan or building permit application submitted for a lot in or partly in a D-1 or D-3 District that involves the addition or enlargement of structures or any amendment to an approved site plan is subject to this section. This subsection applies whether the use is listed in the Use Matrix, or is allowed by variance, special exception, conditional use permit or other similar permission, or is a prior nonconforming use.

(2) Standards applicable to D-1 and D-3 Districts.

(a) Permitted uses for each district are established in the Use Matrix (§ 190-15).

(b) Setbacks and other dimensional regulations are governed by the Dimensional Matrix (§ 190-16).

(c) Hard-surfaced exterior wall materials are required. This can include brick, wood, brownstone, limestone, concrete masonry units (CMUs), parged block, painted brick, stone, terra cotta, stucco, EIFS, or plaster. Vinyl, plastic, metal, structural or unfinished concrete, painted concrete blocks, and tinted or reflective glass are not permitted as the primary exterior facade surface. However, vinyl, wood, plastic or glass block may be used as accent elements surrounding a doorway or window.

(3) Procedures and alternative standards. In order to provide flexibility while maintaining the character of built environment in the downtown area, this section provides several alternatives for development approval, as follows:

(a) The applicant may conform to the standards established in this section for each district. (See Subsection B for D-1 or Subsection C for D-3.) If the application does not request a conditional use (see § 190-15), the applicant may proceed directly to building permit or certificate of occupancy approval without filing a site plan; or

(b) As an alternative, the applicant may request an alternative standard. If the applicant chooses this alternative, the applicant must file a site plan with the Planning Board. The format for the site plan is prescribed in § 190-280. The procedures and standards for this alternative shall be as established in § 190-23D through F for the Mixed Use Overlay District. As part of the site plan approval, the Planning Board may modify any of the dimensional standards or design standards; or

(c) An applicant may continue to elect to seek variances from the Zoning Board of Adjustment.

B. Downtown 1 (D-1).

Purpose: The D-1 Downtown District is established:
•	To promote the goals, objectives and strategies adopted as part of the City's Downtown Master Plan along Main Street between Nashua River and Hollis Street.
•	To preserve and build upon "Walking Main Street" and its walkable, vibrant, and safe character.
•	To foster the mix of retail, offices, and restaurants, working towards the goal of the "twenty-four-hour city."

(1) Building height. A minimum height of two stories shall be required for all new structures (not including additions) even if the building contains only one functional story. The maximum height permitted in the district is six stories or 90 feet, excluding those features excluded from height limits by § 190-16.

(2) Building design.

(a) Buildings shall be oriented to the street. A building is "oriented to the street" where all of the following apply:

[1] A principal entrance to a building faces a street, or is open to a square or plaza. All street-level uses with sidewalk frontage shall be furnished with an individual entrance and direct access to the sidewalk in addition to any other access that may be provided.

[2] Off-street parking does not lie between the building's principal entrance and the street.

[3] Pedestrian access from the public sidewalk, street right-of-way or driveway to the principal structure is provided through a hard surface.

(b) The front facade of commercial buildings shall be aligned with the finished grade of the street except as otherwise provided herein.

(c) The principal entry for a residential, civic use or a civic building may include a stoop, portico, colonnade, or a portal.

(3) Building fenestration; storefronts and other uses.

(a) This subsection applies to storefronts and any use except to the conversion of a residential building to a commercial use.

(b) Facades facing or visible from a public street shall include at least four of the following elements:

[1] A pediment.

[2] A cornice adjoining the top of the roof or top of the facade.

[3] Windows in each story above the ground level. Individual window openings shall not exceed four feet horizontally and eight feet vertically. Circular, semicircular and octagonal windows are permitted.

[4] Architectural treatment to articulate the middle of any two-story building, or the first and second floors of a building exceeding two stories, including molding, a canopy, a transom, or similar elements.

[5] A recessed entryway consistent with the requirements of Subsection B(3)(e) below.

(c) Between 60% to 90% of the length, and at least 50% of the surface, of the first floor street frontage shall be in transparent public entrances or windows (including retail display windows). Between 10% to 50% of the surface of the front facade for each floor above the first floor street frontage shall be in transparent windows. At least one public entrance, such as a doorway, shall be accessible from the sidewalk. No windows or openings of storefronts shall utilize a mirrored reflective film. Films allowing light to pass through but blocking ultraviolet light are permitted. The intent is that interior displays will be visible from the right-of-way.

(d) Building frontages that face public streets and exceed a width of 20 feet must include vertical piers or other vertical visual elements to break the plane of the building frontage. Such vertical piers or vertical elements must be spaced at intervals of 15 feet to 35 feet along the entire building frontage. Vertical visual elements may include entryways, windows, columns, colonnades, or other form of modular fenestration.

(e) Doors may be recessed into the face of the building to provide a sense of entry and to add variety to the streetscape. The ground surface of an entryway shall not be less than 15 square feet. Door openings shall not exceed six feet horizontally and 10 feet vertically. Overhead doors for loading docks, delivery and distribution shall be permitted only on the rear of the building.

(f) Roofs shall not mask or obscure the architectural features of the front facade such as pediments or cornices.

(4) Canopies, arcades and awnings. Canopies, arcades, awnings, and similar appurtenances may be constructed over the entrance to any building, and/or over windows subject to the following criteria. Canopies, awnings and similar appurtenances are encouraged at the entrances to buildings and in open space areas. Such features may be constructed of rigid or flexible material designed to complement the streetscape of the area. Such features shall not obscure the upper stories or a sign panel located above the first floor. Any such facility may extend from the building to within two feet of the back of the curb. Vertical supports for such features are not allowed in the public right-of-way. No canopy shall extend into the public right-of-way unless any encroachment permit or agreement required by the City and state has been approved and issued.

(5) Access standards. Driveways with ingress and egress onto alleys are preferred. No new driveways are permitted on a collector or arterial street, except as provided for parking entrances.

(6) Landscaping requirements. See Article XXVII.

(7) Lighting. Lighting is not subject to Article IX, Lighting. Lighting shall be installed above front entrances to buildings located in the D-1 District. All lighting shall be directed on site or onto adjacent walkways and shall be shielded from direct off-site viewing.

(8) Off-street parking requirements.

(a) Parking ratios. No minimum number of off-street parking spaces is required.

(b) Location. No off-street parking (whether it is a principal or an accessory use) is permitted between a principal structure and the street. Surface parking areas shall not adjoin a street, but may adjoin an alley. Surface parking shall be located to the rear of buildings.

(c) Entrances. One opening or entrance to a parking area is permitted per block face adjoining a public street. There is no limit on the number of opening or access points for that portion of lots or parcels adjoining an alley. The opening or entrance shall not exceed 36 feet in width. No opening that requires an access from the public right-of-way that reduces on-street parking is permitted except for parking areas that are reserved for use by the general public.

(d) Loading docks. Loading/unloading docks or designated loading areas shall be located only in the rear or side yard.

(e) Surface. Parking areas shall have a paved surface or a hard surface. Ground surface areas not covered with a paved surface or a hard surface shall be restricted from parking by signage and curbing, fencing, or other physical barriers.

(9) Utilities and trash receptacles. See § 190-182, Screening of service or storage areas. In addition:

(a) All new transformer vaults, utility structures, air vents, backflow preventers, or any other similar devices, except these facilities when located below grade, must be located behind the front setback or the front facade, whichever is furthest from the front property line.

(b) All roof-mounted equipment, including satellite dishes and other communication equipment, shall be screened so as not to be visible from any public right-of-way by a parapet or similar structure that is similar to the architectural style of exterior elevation of the principal building.

C. Downtown District (D-3).

Purpose: The D-3 Downtown District is established:
•	To promote the goals, objectives and strategies adopted as part of the City's Downtown Master Plan along Main Street between Otterson Street and Salmon Brook.
•	To concentrate Downtown's retail growth potential in a second retail node along Main Street South.
•	To create mixed-use buildings with mandatory, traditional storefronts oriented toward Main Street with retail uses at the ground floor.
•	To support existing and proposed infrastructure investments such as broad sidewalks, street trees, and on-street parking with awnings, and active storefronts to create a vibrant pedestrian-oriented retail node.

Source: Urban Design Associates

Source: Urban Design Associates

(1) Permitted uses. Dwelling units are permitted above the first floor of any building with commercial and/or retail uses on the first floor.

(2) General standards and building form. Buildings, lots and parcels shall conform to the standards established subsection § 190-20B(2) through (9) above.

(3) Circulation.

(a) Sidewalks shall be provided by the individual developers and property owners. All sidewalks shall connect to the existing/proposed sidewalks, parking areas, buildings, and public spaces. Public sidewalks shall be a minimum of six feet wide. The applicant may grant an easement to the City for the sidewalk and a planting area between the sidewalk and the paved section of the street.

(b) Pedestrian walkways shall be provided mid-blocks and between properties, connecting the sidewalks in front of the building with the parking behind the building. Walkways can be either interior to a building or exterior. Lighting shall be provided for pedestrian safety. Amenities such as seating and planters should be provided in or at the entrance to alleys to encourage pedestrian circulation. The walkways shall be a minimum of four feet wide. The maximum side setback is waived to the extent needed to accommodate a pedestrian walkway.