Performance Zoning Model Ordinance 

Table of Contents 

Introduction 
Amendments to the Zoning Ordinance 

Article I. Definitions 
Article II. Purpose and Intent of Districts 
Article III. Use Regulations 
Article IV. Natural Resource Protection Standards 
Article V. Open Space in Residential Developments

Amendments to the Subdivision and Land
Development Ordinance 

Performance zoning has a primary objective of protecting natural resources and a secondary objective of providing flexibility in the design of residential developments. The performance zoning approach to residential development addresses the primary objective by limiting the amount of development intrusion that may occur in the various natural resources. In addition to the natural resource protection standards, the zoning technique contains three primary performance criteria: minimum open space, maximum density, and maximum impervious surface. The intensity of development for each residential development is determined through a site evaluation and compliance with the three performance standards. 

The protection of natural resource features is accomplished by limiting the extent of development intrusion into each resource. A specific minimum open space standard is assigned to each natural resource. For example, floodplains and wetlands must remain as 100 percent open space--no development may occur on these natural resources. For a slope of 25 percent or greater, 80 percent must remain as open space with no more than 20 percent being altered or developed. 

The first step for a developer working under the performance zoning concept is to map the natural resources on the site and determine the buildable area. The determination of the buildable area is accomplished through an analysis known as the site capacity calculations. These calculations make performance zoning and the application of natural resource protection standards site specific. The bottom line of the site capacity calculations is the required open space and the maximum number of dwelling units for the subject site. The key to calculating those numbers is the net buildable site area, which is the area of the site that is suitable for building. Briefly, the net buildable site area is calculated by subtracting the area within the right-of-way of existing roads and the protection area of each natural resource from the total site acreage. The site capacity calculations produce two open space figures. The first is the protection area for the natural resources on the particular site. The other is a calculated area based on the minimum open space requirement for the zoning district. The larger of the two numbers is used to calculate the net buildable site area, and is the minimum required open space for that tract. Thus, the natural features directly influence the required minimum open space and the net buildable site area for each tract of land proposed for residential development. 

The second objective--providing flexibility in the design of residential developments--is accomplished by permitting a full range of dwelling unit types. The list of permitted dwelling unit types ranges from single-family detached to apartments. The flexibility is realized in two ways. First, it gives the applicant’s designer flexibility in working with a site that is constrained by natural features. On a tract with a high percentage of natural resources, the maximum density could be achieved with townhouses and garden apartments, whereas the maximum number of dwelling units would not be possible with single-family houses or even twins. Second, a developer has flexibility to respond to market conditions. For example, if a developer determines there is a market for townhouses, he/she can propose them without requesting a zoning change to a district which permits townhouses. While the performance zoning concept advocates that the complete list of housing types be permitted in all residential zoning districts, practice has shown that some municipalities in Bucks County have used an abbreviated list in some districts. Low- to medium-density districts are usually where only a few housing types will be permitted. There are townships in Bucks County, however, that permit all housing types even in rural and agricultural districts. 

In Bucks County the predominant application of performance zoning by municipalities is in development districts. A development district is the area of the community which the municipal comprehensive plan has identified for higher density residential development. The performance zoning concept is implemented in municipal zoning ordinances as a permitted use in various residential districts. This use is generally called performance standard subdivision. Other permitted uses in the district include conventional single-family dwellings, single-family cluster subdivision, and other typical uses permitted in residential districts. A few townships in the county permit performance standard subdivisions in rural and agricultural districts in addition to the development district as the Bucks County Planning Commission publication Performance Zoning suggests. In those instances the ordinance will require a high open space ratio and a maximum density that is commensurate with the maximum density for a single-family cluster in that district. 

These model regulations replace those in the Technical Appendix of Performance Zoning. 

Some modification may be necessary to incorporate these model regulations into a municipal zoning ordinance. A word of caution is offered with Section 301 Table of Performance Standards. The three primary performance standards, open space, density, and impervious surface, are examples of a range from a rural district to districts in the development area. The unit values for the three performance standards are very closely related. Therefore, if one value is adjusted the other two must be changed also. For assistance in adapting this model ordinance or in modifying the performance standards, please contact the staff of the Bucks County Planning Commission. 

Amendments to the Zoning Ordinance 

Article 1. Definitions 

The following terms should be added to the definition section of the municipal zoning ordinance. 

Section 100 Building Envelope 

The building envelope is that area of a lot that has no development restrictions. The building envelope shall not include the area of any required setbacks, buffer yards, natural features with 100 percent protection standard and the portion of those natural features that may not be developed or intruded upon as specified in Section 400 Natural Resource Protection Standards. 

Section 101 Density 

Density is a measure of the number of dwelling units per unit of area. It shall be expressed in dwelling units per acre. The measure is arrived at by dividing the number of dwelling units by the net buildable site area. See Section 301 Table of Performance Standards for the density requirements for the various districts and the Site Capacity Calculations of Section 402 for the calculations to determine the net buildable site area. 

Section 102 Floodplain 

A floodplain consists of areas adjoining a watercourse, ponds or lakes subject to the 100-year-recurrence-interval flood. The areas considered to be floodplain within the municipality shall include those areas identified as being subject to the 100-year flood in the Flood Insurance Study for the municipality prepared by the Federal Insurance Administration dated ______ and the accompanying flood boundary and floodway map dated ____. Floodplain soils shall be used to delineate the floodplain of watercourses that have not been mapped. 

A. Floodway--That portion of the floodplain including the watercourse channel and adjacent land areas which must be reserved to carry the 100-year-recurrence-interval flood without cumulatively increasing that flood elevation more than 1 foot. 

B. Flood Fringe--That portion of the floodplain which is outside the floodway. 

C. Approximate 100-Year Floodplain--That portion of the floodplain for which no detailed flood profiles or 100-year flood elevations have been provided. 

Section 103 Floodplain Soils 

Areas subject to periodic flooding and listed in the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania, U.S. Department of Agriculture; Soil Conservation Service, July, 1975, as being "on the flood plain" or "subject to flooding." The following soil types are flood plain soils: 
 

Alluvial land (Ae)	Marsh (Mh)
Alton gravely loam, flooded (AlA)	Pope loam (PoA)
Bowmansville silt loam (Bo)	Rowland silt loam (Ro)
Hatboro silt loam (Ha)

Section 104 Hydric Soils 

A hydric soil is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions that favor the growth and regeneration of wetlands vegetation. Wetlands vegetation are those plant species that have adapted to the saturated soils and periodic inundations occurring in wetlands. the following soils, classified in the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania, U.S. Department of Agriculture, Soil Conservation Service, July 1975, are hydric soils: 
 

Bowmansville silt loam (Bo)	Hatboro silt loam (Ha)
Doylestown silt loam (DoA)	Towhee silt loam (ToA, ToB)
Fallsington silt loam (Fa)	Towhee extremely stony silt loam (TwA, TwB)
Towhee silt loam	Towhee extremely stony silt loam

Section 105 Impervious Surface 

Impervious surfaces are those surfaces which do not absorb rain. All buildings, parking areas, driveways, roads, sidewalks, and any areas in concrete, asphalt, and packed stone shall be considered impervious surfaces within this definition. In addition, other areas determined by the municipal engineer to be impervious within the meaning of this definition shall also be classed as impervious surfaces. 

Section 106 Impervious Surface Ratio 

The impervious surface ratio is a measure of the intensity of use of a piece of land. It is measured by dividing the total area of all impervious surfaces within the site by the base site area. 

Section 107 Lake and Ponds 

Lakes and ponds are natural or artificial bodies of water which retain water year-round. Artificial ponds may be created by dams, or result from excavation. Lakes are bodies of water two or more acres in extent. Ponds are bodies of water less than two acres in extent. 

Section 108 Lake and Pond Shorelines 

Lake and pond shorelines are the landside edge of lakes and ponds from established shoreline to an upland boundary. Lake and pond shorelines shall be measured 100 feet from the spillway crest elevation. 

Section 109 Lot Area 

The lot area is contained within the property lines of the individual parcels of land shown on a subdivision plan or required by this ordinance, excluding any area within an existing or designated future street right-of-way, or the area of any easement which would interfere with the proposed use. In addition, the minimum lot area does not include any area designated as open space under the requirements of Section 402 Site Capacity Calculations and Section 301 Table of Performance Standards. 

Section 111 Open Space Ratio 

The open space ratio is a measure of the intensity of land use. It is calculated by dividing the total amount of open space within the development by the base site area. 

Section 112 Performance Standard Subdivision 

A performance standard subdivision is a type of cluster development in which the developer may choose from a variety of housing types subject to the regulations in Section 300 Use A3 of this ordinance. The performance standard subdivision use promotes the grouping or clustering of dwelling units, permits a variety of housing types to encourage better, more flexible designs. The subdivision as a whole must meet prescribed standards for open space, density, and impervious surfaces. 

Section 113 Site Area 

The site area is all land within the tract as defined in the deed. This area shall be computed from an actual site survey rather than from a deed description. 

Section 114 Site Area Base 

The site area base of a tract is the land remaining after subtracting land which is not contiguous, land previously subdivided, future road rights-of-way and existing utility rights-of-way from the site area. See section 402 for the specific calculations. 

Section 115 Buildable Site Area 

The buildable site area is the area of the site which may be altered, disturbed, or regraded for development purposes. The buildable site area could contain buildings, roads, parking areas, sewage systems, and stormwater management facilities. The buildable site area shall not contain required open space, recreation, or natural resource protection areas. 

Section 116 Site Capacity 

Site capacity is the maximum number of dwelling units, the maximum impervious surface, the buildable portion of the site, and the minimum open space as calculated under the provisions of Site Capacity Calculations in Section 402. 

Section 117 Steep Slopes 

Areas where the average slope is 15 percent or greater, which, because of this slope, are subject to high rates of stormwater runoff and, therefore, erosion and flooding. 

Section 118 Tree Protection Zone (TPZ) 

An area that is radial to the trunk of a tree in which no construction activity shall occur. The tree protection zone shall be 15 feet from the trunk of the tree to be retained, or the distance from the trunk to the dripline, whichever is greater. Where there is a group of trees or woodlands, the tree protection zone shall be the aggregate of the protection zones for the individual trees. 

Section 119 Watercourse 

A watercourse is any natural or artificial stream, river, creek, ditch, channel, canal, waterways, gully, or ravine in which water flows in a definite direction or course, either continuously or intermittently, and has a defined bed and banks. 

Section 120 Wetlands 

Wetlands are those areas that are inundated and saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, and similar areas. 

Section 121 Wetland Margin 

A wetland margin is transitional area extending from the outer limit of the wetland. 

Section 122 Woodlands 

A woodland is one-quarter acre or more of wooded land where the largest trees measure at least 6 inches diameter at breast height (dbh) or 4.5 feet from the ground. The woodland shall be measured from the dripline of the outer trees. Woodlands are also a grove of trees forming one canopy where 10 or more trees measure at least 10 inches diameter at breast height (dbh). 

Article II. Purpose and Intent of Districts 

The residential zoning districts in this model ordinance are based on the principles of the development district concept. Four primary categories of districts are recommended by the concept--development area, urban area, reserve area, and natural resource protection area. The development area is the portion of the municipality that has been determined by the comprehensive plan to be the most suitable place for the anticipated growth to occur. Urban areas are boroughs, villages, or other developed areas in which, for the most part, only in-fill development is possible. Reserve areas are essentially suitable for development but are not needed for higher intensity development during the time frame of the municipality’s comprehensive plan. When the land within the development area has been developed, a portion of the reserve area will be rezoned to development district classifications. The purpose of natural resource protection districts is to protect the areas of sensitive natural features in the municipality. 

The description of the districts and the model regulations are intended to provide a fundamental understanding of the objectives of the districts. The type and number of districts, the permitted uses and dimensional regulations for each must be carefully established. The drafting of the various district regulations should be done by a land planner who is familiar with "Performance Zoning." The staff of the Bucks County Planning Commission is available to assist municipal officials.  

This article provides a description of the purpose and intent of each district used in this model ordinance, as well as model language to use in drafting the amendments to the municipal ordinance. 

Section 200 Reserve Areas 

The purposes of the zoning districts in reserve areas are to maintain the rural character of the area for the foreseeable future; to preserve large environmentally sensitive areas; to protect and enhance the character of existing rural villages; and to protect the general scenic quality of the area. 

A. Resource Protection District (RP)--The purpose of this district is to protect areas consisting primarily of sensitive natural features such as woodlands, steep slopes, wetlands, floodplains, and lakes and ponds. Development standards are such as to ensure that these resources are permanently protected. 

B. Rural Agricultural District (RA)--The purpose of this district is to provide standards for low-intensity development in rural areas until these areas are both needed for development and provided with utilities. The intensity of use is intended to be such that development which does occur will not require urban services. 

C. Rural district (R1)--The purpose of this district is to provide for limited, low-density residential development in areas which are now served with public sewers or for which a need for higher intensity development does not exist. 

Section 201 Development Areas 

A development area(s) is established to accommodate the anticipated growth of the municipality for a specific period of time. The zoning districts of development areas provide areas for residential, commercial, industrial and other nonresidential uses. The infrastructure needed to sustain these developed activities must be available to support these activities. The purpose of development areas is to control and regulate development so as to coordinate the municipality’s growth with the provision or public services and facilities. Within this area, development is encouraged to promote the efficient use of land and a well-balanced community. 

A. Suburban Medium District (SM)--It is the purpose of the SM district to provide for medium-density residential development. A variety of residential uses are encouraged, including clustering and the provision of open spaces. 

B. Suburban High District (SH)--It is the purpose of the SH district to provide for higher densities of residential development. A variety of residential uses are encouraged. The higher intensities relate to similar uses in adjacent developed areas and are located in areas with few natural limitations. 

C. Urban Residential District (UR)--It is the purpose of this district to retain the urban character of existing residential areas as well as to provide for future residential development in a variety of housing types at appropriate densities. 

Article III. Use Regulations 

This model ordinance uses the format of including the regulations of all uses in one section of the ordinance rather than listing the use regulations with each zoning district. The model use regulations can also be incorporated into a zoning ordinance that has a separate section for each zoning district with each district having a complete set of permitted uses. The third format option is to have all of the use regulations in a section and having a section for each district with the use listed according to those permitted by right, conditional use, and special exception. 

Section 300 Residential Uses 

Use A1 Single-Family Detached--A single-family detached dwelling on an individual lot with private yards on all sides of the house. Detached dwellings may include dwellings constructed on the lot, prefabricated dwellings, manufactured dwellings, modular dwellings, and mobile homes. 

A. No more than one single-family detached dwelling shall be placed on a lot and such detached dwelling shall be occupied by not more than a single family. 

B. Area and Dimensional Requirements 

View Table

C. If the dwelling is a mobile home, the following conditions shall also apply: 

1. The area between ground level and the perimeter of the mobile home shall be enclosed by means of wood or aluminum skirting or other similar material. 

2. Each mobile home shall be placed on a permanent foundation of at least 8 poured concrete or masonry pillars set on a concrete base at least 8 inches thick. The pillars shall be spaced no more than 10 feet apart with the end piers being no farther than 5 feet from the ends of the unit. The pillars shall be at least 1 foot by 2 feet in size and at least 36 inches below grade. Each pillar shall have installed a tie-down ring to which the mobile home shall be secured. 

D. Parking--Three off-street parking spaces for dwellings having three bedrooms or fewer; four off-street parking spaces for dwellings have four bedrooms or more. 

Use A2 Single-Family Detached Cluster--Single-family detached dwellings on individual lots with private yards on all sides of the houses which are clustered to preserve common open space. Detached dwellings may include a dwelling constructed on the lot, a prefabricated dwelling, a manufactured dwelling, a modular dwelling, and a mobile home. 

A. No more than one single-family detached dwelling shall be placed on a lot and such detached dwelling shall be occupied by not more than a single family. 

B. The requirements of Section 301 Table of Performance Standards shall be met. 

C. Area and Dimensional Requirements 

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D. In the RI, SM, SH, and UR districts, the one side yard may be reduced to 5 feet provided that the total width of the two side yards shall equal the total required by the chart for the district. 

E. If the dwelling is a mobile home, the requirements of Section 300.A1.C shall be met. 

F. Parking--three off-street parking spaces for dwellings having three bedrooms or less; four off-street parking spaces for dwellings having four bedrooms or more. 

Use A3 Performance Standard Subdivision--A performance standard subdivision is a type of cluster development in which the developer may choose to develop a variety of housing types subject to the regulations stated below and all other applicable requirements of this ordinance. Performance standard subdivisions allow the grouping or clustering of dwelling units, permitting a variety of housing types to encourage better, more flexible designs. The subdivision as a whole must meet prescribed standards for open space, density, and impervious surfaces. 

A. General Requirements 

1. The requirements of Section 301 Table of Performance Standards shall be met. 

2. Dwelling Unit Mix--A mix of dwelling unit types is necessary to promote a balanced community. Therefore, a mix is required, based on the total number of dwelling units as set forth in the accompanying table. 
 

Number of Dwellings in Development	Minimum Required Number of Dwelling Unit Types	Maximum any Dwelling Unit Type	Minimum Dwelling Unit Type
1 - 60	1	100%	20%
61 - 150	2	60%	15%
151 - 400	3	40%	10%
401 or more	4	40%	5%

3. Parking Requirements--Units containing three bedrooms or less shall provide a minimum of three off-street parking spaces. Units containing four bedrooms or more shall provide a minimum of four off-street parking spaces. 

4. The developer of a performance standard subdivision shall be subject to the maximum impervious surface ratio specified in Section 301, Table of Performance Standards. 

5. There shall be a minimum building setback of 50 feet along the property lines that form the perimeter of the tract being developed. 

B. Requirements for Housing Types 

1. Single-Family Detached--A single-family detached dwelling unit on an individual lot with private yards on all sides of the house. Detached dwellings may include a dwelling constructed on the lot, a prefabricated dwelling, a manufactured dwelling, a modular dwelling, and a mobile home. 

a) If the dwelling is a mobile home, the requirements of Section 300.A1.C shall be met. 

b) Area and dimensional Requirements 

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2. Detached Dwelling, Off Center--A single-family detached dwelling unit on an individual lot with private yards on all sides of the house. The building is set close to one side property line with a side yard which may be reduced to 5 feet and the other side yard shall be no less than 15 feet. 

a) The standards noted in B.1. above for single-family detached dwellings shall be met except for the side yard requirement. 

b) A minimum building spacing of 20 feet shall be provided between dwelling units. 

3. Village House--A single-family detached dwelling unit on an individual lot with private yards on all sides of the house. A village house differs from other forms of detached housing in its lot size and placement on the lot. It is similar to houses found in historic villages and towns. The house is placed close to the street and is additionally distinguished by planting or architectural treatments. 

a) Each unit shall meet two or more of the following characteristics: 

1) An unenclosed porch, running across at least three quarters of the house front, extending at least 7 feet from the house. 

2) A front yard raised above sidewalk grade by at least 30 inches and a retaining wall of at least 18 inches at the sidewalk line. 

3) A front yard enclosed by a wall or fence of permanent construction at least 30 inches in height and one flowering shrub 60 inches across the width of the front of the house. 

4) Hedge of shrubs planted 18 inches on center for width of yard facing street and two flowing trees. 

5) Two canopy trees per lot or three flowering trees per lot. 

6) One flowering tree, and one flowering shrub per 90 inches of yard facing street. 

b) Dimensional Requirements 
 

Minimum lot area:	6,000 square feet
Minimum setbacks:
house:	15 feet -- front
	30 feet -- rear
	5 feet -- side
garage:	25 feet -- front
	30 feet -- rear
	5 feet -- side
Minimum Lot width at setback:	50 feet
Maximum building height:	35 feet

c) Landscaping Requirements 
 

Canopy trees:	2 inch caliper
Flowering trees:	2 inch caliper
Flowering shrubs:	3 feet high
Hedge shrubs:	3 feet high

4. Twin -- A single-family semidetached unit having only one dwelling from ground to roof and only one wall in common with another dwelling unit. There shall be no more than two dwelling units per structure. 

a) Area and Dimensional Requirements 

a) Area and Dimensional Requirements 
 

Minimum lot area per building:	6,000 square feet
Minimum lot width at setback line:	60 feet
Minimum yards:
front:	30 feet
side:	15 feet
rear:	20 feet
Maximum building height:	35 feet

6. Patio House--A detached or semidetached unit, with one dwelling unit from ground to roof having individual outside access. Except for the street setback, the lot shall be fully enclosed by a wall 4 to 6 feet in height. All living spaces, i.e., living rooms, dens, and bedrooms, shall open onto a private open area or patio. 

a) Area and Dimensional Requirements 
 

Minimum lot area:	4,000 square feet
Minimum lot width at setback line:	40 feet
Minimum setback - street line:	5 feet
Maximum building height:	25 feet
Minimum patio area (ratio to lot area):	65 percent
Minimum patio dimensions:	20 feet

7. Atrium House--The atrium house is a single-family, attached dwelling unit, one story high, with individual outside access. The lot shall be fully enclosed by a wall at least 7 feet high. A private yard, herein called an atrium, shall be included on each lot. All living spaces, i.e., living rooms, den, and bedrooms, shall open into the atrium. A row of attached dwellings shall not exceed five dwelling units. 

a) Area and Dimensional Requirements 
 

Minimum lot area per dwelling unit:	2,100 square feet
Minimum lot width at setback line:	40 feet
Minimum setback-street line:	10 feet
Maximum building height:	15 feet
Minimum atrium area (ratio to lot area):	35 percent
Minimum atrium dimensions:	16 feet

8. Multiplex--an attached dwelling unit which may be arranged in a variety of configurations: side by side, back to back, or vertically. The dwelling units share a common lot area which is the sum of the required lot areas of all dwelling units within the building. The essential feature is the small number of units attached. No more than six units shall be attached in any structure, and structures shall average four units each. Each unit shall have individual outside access. 

a) Area and Dimensional Requirements 
 

Minimum lot area (per building):	8,000 square feet
Minimum lot area (per dwelling unit):	2,500 square feet
Minimum lot width at setback line (per building):	80 feet
Minimum building setback:
street:	30 feet
parking area:	10 feet
pedestrian walkway:	5 feet
Minimum rear yard:	20 feet
Minimum building spacing:	30 feet
Minimum building height:	35 feet

9. Townhouse—A single-family attached dwelling unit with one dwelling unit from ground to roof, having individual outside access. A row of attached townhouses shall not exceed eight dwelling units. 

a) Area and Dimensional Requirements 
 

Minimum lot area:	2,000 square feet
Minimum lot width:	24 feet
Minimum building setback:
street:	20 feet
parking area:	30 feet
pedestrian walkway:	15 feet
Minimum building spacing:	30 feet
Minimum rear yard:	20 feet
Maximum building height:	35 feet

10. Apartments—A grouping of dwelling units sharing common elements which may include common outside access. The dwelling units share a common lot area, which is the sum of the required lot areas of all dwelling units within the building. Apartments shall contain three or more dwellings in a single structure. 

a) Area and Dimensional Requirements 
 

Minimum lot area (per building):	1 acre
Minimum lot area (per dwelling unit):	2,000 square feet
Minimum street frontage	100 feet
Minimum building setback:
street:	50 feet
parking area:	30 feet
pedestrian walkway:	5 feet
Minimum building spacing:	50 feet
Maximum number of units per building:	16
Maximum building height:	35 feet

Use A4 Other Uses—Other use types will also be permitted in the various residential districts such as general farming, school, place of worship, and accessory uses. The list of uses permitted in each district is at the discretion of the municipal officials. 

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Article IV. Natural Resource Protection Standards 

Section 400 Natural Resource Protection Standards 

All uses and activities established after the effective date of this ordinance shall comply with the following standards. Site alterations, regrading, filling, or clearing of any natural resources prior to the submission of applications for zoning or building permits or the submission of plans for subdivision or land development shall be a violation of this ordinance. In the event that two or more resources overlap, the resource with the greatest protection standard shall apply to the area of overlap. 

A. Floodplain—The entire extent of an area identified as within the floodplain of the 100-year recurrence-interval flood shall not be altered, regraded, filled or built upon except in conformance with Section 403 Floodplain Regulations of this ordinance. For areas designated as "Approximate 100-Year Floodplain" along streams and watercourses where the 100-Year floodplain (with a floodway and flood fringe) has not been delineated, the requirements of Floodplain Soils shall be met. Minor road crossings may be permitted in the floodplain where design approval is obtained from the municipality and the Pennsylvania Department of Environmental Protection and if no other reasonable access is available. 

B. Floodplain Soils—The entire extent of such areas shall not be altered, regraded, filled or built upon except in conformance with Section 403 Floodplain Regulations of this ordinance. Minor road crossings may be permitted in floodplain soils where design approval is obtained from the municipality and where no other reasonable access is available. Floodplain soils shall not be used where the 100-year floodplain (with a floodway and flood rings) has been delineated. 

Studies prepared by a registered engineer or expert in the preparation of hydrological studies may be used to delineate the 100-year floodplain with a floodway and flood fringe in place of areas designated at "Floodplain Soils" and "Approximate 100-Year Floodplain." Such hydrological studies shall be subject to the review and approval of the governing body on the recommendation of the municipal engineer. 

C. Steep slopes—In areas of steep slopes, the following standards shall apply: 

1. 15 percent to 25 percent. No more than 30 percent of such areas shall be altered, regraded, cleared or built upon. 

2. 25 percent or steeper. No more than 15 percent of such areas shall be altered, regraded, cleared or built upon. 

3. Areas of steep slope that are less than 3,000 square feet shall be exempted from these standards. 

D. Woodlands—The following standards shall apply to woodlands. 

1. Woodlands in Environmentally Sensitive Areas—No more than 20 percent of woodlands located in environmentally sensitive areas shall be altered, regraded, cleared, or built upon. Environmentally sensitive areas shall include floodplains, floodplain soils, steep slopes, wetlands, wetland margins, and lake or pond shorelines. 

2. Other Woodland Areas—No more than 50 percent of woodlands which are not located in environmentally sensitive areas (as defined in 1. Above) shall be altered, regraded, cleared, or built upon. 

E. Tree Protection zone—The entire extent of such areas shall not be altered, regraded, compacted, or built upon, nor used for storage or parking of vehicles. 

F. Watercourses—The entire extent of such areas shall not be altered, regraded, filled, piped, diverted or built upon except where design approval is obtained from the municipality and, if required, the Pennsylvania Department of Environmental Protection. 

G. Wetlands—The entire extent of such areas shall not be altered, regraded, filled, piped, diverted, or built upon except where state and federal permits have been obtained. 

1. Delineation of Wetlands—When the National Wetlands Inventory (NWI) Maps indicate wetlands on a site or when a site contains hydric soils or an area with a predominance of wetlands vegetation, a on-site investigation shall be conducted to determine if wetlands are present on the site. A landowner or an applicant shall use one of the following methods to delineate wetlands: 

a) Wetland boundaries shall be delineated through an on-site assessment which shall be conducted by a professional soil scientist or others of demonstrated qualifications. Such a person shall certify that the methods used correctly reflect currently accepted technical concepts, including the presence of wetlands vegetation, hydric soils and/or hydrologic indicators. A study shall be submitted with sufficient detail to allow a thorough review by the municipality. The study must be approved by the governing body. 

b) A wetlands delineation validated by the U.S. Army Corps of Engineers. In the event that a wetlands delineation validated by the U.S. Army Corps of Engineers is shown to vary from a wetlands boundary derived from subsection a. above, the Corps delineation shall govern. 

2. Wetlands shall not be altered, regraded, filled, piped, diverted, or built upon except where State and Federal permits have been obtained. 

H. Wetlands Margin—No more than 20 percent of such areas shall be altered, regraded, filled, or built upon. In addition, any Department of Environmental Protections’ regulations under Chapter 105 concerning activities in wetlands margins shall be met. 

For the purposes of this ordinance, the wetlands margin shall extend 100 feet from the wetland boundary or to the limit of the hydric soils, whichever is less. The limit of hydric soils shall be as mapped in the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania, U.S. Department of Agriculture, Soil Conservation Service, July 1975, unless reclassified by a Certified Soil Scientist. 

I. Lakes and Ponds—The entire extent of such areas shall not be altered, regraded, filled, piped, diverted, or built upon. 

J. Lake and Pond Shorelines—For the purposes of this ordinance, lake and pond shorelines shall be measured 100 feet from the spillway crest elevation. No more than 20 percent of such areas shall be altered, regraded, filled, or built upon. 

Section 401 Application of Natural Resource Protection Standards 

A. Plan Information—To meet the natural resource protection standards of Section 400 of this ordinance, the following information is required to be provided with an application for a subdivision or land development plan and/or a zoning permit. 

1. A site plan which illustrates all natural resources and the proposed use for the site; 

2. All encroachments and disturbances necessary to establish the proposed use on the site; 

3. Calculations which indicate the area of the site with natural resources and the area of natural resources that would be disturbed or encroached upon. 

B. Building Envelope—The area of a lot that has no development restrictions. The building envelope shall not include the area of any required setbacks, buffer yards, natural features with 100 percent protection standard and the portion of those natural features that may not be developed or intruded upon as specified in Section 400 of this ordinance. The purpose of identifying a building envelope is to provide sufficient area for the general location of the building, driveway, patio, other improvements, and site alterations while meeting natural resources protection standards and minimum setback requirements of this ordinance. 

Within any proposed subdivision, all residential lots shall have a contiguous building envelope of at least an area as indicated below: 

View Table

C. Deed Restrictions—For subdivision and land development plans, restrictions meeting municipal specifications must be placed in the deed for each site or lot that has natural resource protection areas within its boundaries. The restrictions shall provide for the continuance of the resource protection areas in accordance with the provisions of this ordinance. Natural resource protection areas may be held as common open space in accordance with the requirements of Section ___ of the ___ Subdivision and Land Development Ordinance or in the ownership of individual property owners. For this latter form of ownership, it shall be clearly stated in the individual deeds that the maintenance responsibility lies with the individual property owner. 

D. For uses with on-lot sewage systems, a minimum area of 3,000 square feet, in addition to the building envelope specified in subsection a. above, shall be identified for the location of the sewage. Such additional area shall not include natural features with a 100 percent protection standard nor the portion of those natural features that may not be developed or intruded upon as specified in Section 400. 

Section 402 Site Capacity Calculations 

The following site capacity calculations shall be submitted with applications for Use A2 Detached Dwelling Cluster Subdivision, Use A3 Performance Standard, or Use ___ Mobile Home Park. Through these calculations, the net buildable site area, the maximum number of lots or dwelling units, the maximum amount of impervious surfaces and the required open space will be determined for the specific site. The required open space shall be the amount determined by step 6 of the calculations below. Areas identified as resource protection land shall be included in the required open space for the proposed development. 

A. Base Site Area—Calculate the base site area. From the total site area, subtract future road rights-of-way; existing utility rights-of-way; land which is not contiguous or which is separated from the parcel by a road, railroad or major stream; or land shown on previous subdivision or land development plans as reserved for open space. 

Minimum lot area:	10,000 square feet
Minimum lot width at setback line:	70 feet
Minimum yards:
front:	35 feet
side:	10 feet
rear:	40 feet
Maximum building height:	35 feet

Total Site Area		_____ acres
	-	_____ acres
Base Site Area	=	_____ acres

B. Land with Resource Restrictions and Resource Protection Land—Calculate the land with resource restrictions and the resource protection land. In the event that two or more resources overlap, only the resource with the highest open space ratio shall be used in the calculations. 
  View Table

C. Recreation Land—Calculate land for recreation. 
 

Base Site Area		______ acres
Subtract Land with Resource Restrictions	-	______ acres
Remainder		______ acres
Multiply by 1/3 Minimum Open Space Ratio	x	______ acres
Recreation land	=	______ acres

D. Combine Resource Protection Land and Recreation Land. 
 

Resource Protection Land		______ acres
Add Recreation Land	+	______ acres
Resource Protection and Recreation Land	=	______ acres

E. Standard Minimum Open Space—Calculate the standard minimum open space. 
 

Base Site Area		______ acres
Multiply by Minimum Open Space Ratio	x	______ acres
Standard Minimum Open Space	=	______ acres

F. Determine Required Open Space 
 

The required open space is the total of the resource protection land and recreation land, or the standard minimum open space, whichever is greater.

-

______ acres

G. Net Buildable Site Area—Calculate the net buildable site area 
 

Base Site Area		______ acres
Subtract Required Open Space	-	______ acres
Net Buildable Site Area	=	______ acres

H. Number of Dwelling Units/Lots—Calculate the maximum number of dwelling units 
 

Base Site Area		______ acres
Multiply by Maximum Density for District	x	______ acres
Number of Dwelling Units Permitted	=	______ dwelling units

I. Impervious Surfaces—Calculate the maximum area of impervious surfaces 
 

Base Site Area		______ acres
Multiply by Maximum Impervious Surface Ratio for District	x	______ acres
Maximum Permitted Impervious Surface	=	______ acres

J. Site Capacity Summary 
 

Required Open Space (6)		______ acres
Net Buildable Site Area		______ acres
Maximum Number of Dwelling Units/Lots (8)		______ units
Maximum Impervious Surfaces		______ acres

Section 403 Floodplain Regulations 

This section contains the typical floodplain regulations that are based on the Pennsylvania Department of Community Affairs and Federal Emergency Management Agency guidelines. The provisions should follow the current guidelines. 

Article V. Open Space in Residential Developments 

Common open space is an integral part of a performance zoning development. Article IV provides model language for the designation, design, and ownership of open space. 

Section 500 General Open Space Requirements 

A. Single-family detached clusters, performance standard subdivisions, and mobile home parks shall meet the open space requirements of this ordinance. The plan shall contain or be supplemented by such material as required to establish the method by which open space shall be perpetuated, maintained and administered. The approval of the final plan and other materials shall be construed as a contract between the landowner(s) and the municipality, and shall be noted on all applicable deeds. 

B. Open space shall not include land occupied by nonrecreational buildings or structures, roads or road rights-of-way, parking areas for nonrecreational uses or land reserved for future parking areas for nonrecreational uses, or the yards or lots of dwelling units. 

C. A portion of the open space must be set side as recreation land in accordance with the Site Capacity Calculations of this ordinance. Recreation land shall not include natural features with a 100 percent protection standard nor any portion of those natural features that may not be developed as specified in Environmental Performance Standards. Recreation land may contain impervious surfaces. Such impervious surfaces shall be included in the calculation of the impervious surface ratio. 

D. Layout of Open Space in Other Districts—The open space shall be laid out in accordance with the best principles of site design. It is intended that open space shall be as close to all residences as possible, with greenways leading to major recreation spaces. Major recreation areas shall be located to serve all residents. The open space is most needed in areas of highest density. The intent is to provide open areas as close to the individual unit as possible. 

Section 501 Open Space Designation 

All land held for open space shall be so designated on the subdivision and land development plans. Such plans shall contain the following information: 

A. A statement that the open space land shall not be separately sold or further subdivided, except for transfer to the municipality or a conservation organization approved by the municipality. And, a statement that the open space land shall not be further developed, except for recreational facilities. 

B. The use(s) of the open space shall be indicated on the plans. In designating the use(s), one or more of the following classes may be used: 

1. Lawn—A grass area with or without trees which may be used by the residents for a variety of purposes and which shall be mowed regularly to ensure a neat and orderly appearance. 

2. Natural Area—An area of natural vegetation undisturbed during construction, or replanted. Such areas may contain pathways. Meadows shall be maintained as such and not left to become weed-infested. Maintenance may be minimal, but shall prevent the proliferation of weeds and undesirable plants such as honeysuckle and poison ivy. Litter, dead trees and brush shall be removed, and streams shall be kept in free flowing condition. 

3. Recreation Area—An area designated for a specific recreational use in accordance with Section 402 the Site Capacity Calculations including but not limited to tennis courts, basketball courts, swimming pools, playfields, and tot lots. Such areas shall be maintained so as to avoid creating a hazard or nuisance, and shall perpetuate the proposed use. 

4. Agricultural Area—An area designated for family vegetable plots or to be leased or sold to agricultural area. 

5. Stormwater Management—Not more than one-third of the open space may be used for stormwater detention or retention basins. 

C. The type of recreation facilities to be provided and the extent of proposed improvements shall be noted on the plans, including a planting plan and schedule. 

D. The plan shall note the method by which the open space shall be owned and maintained in accordance with Section 504. 

Section 502 Design Standards for Open Space 

All open space areas shall meet the following design standards: 

A. Layout of Open Space—The open space shall be laid out in accordance with the best principles of site design, and any duly adopted open space plan. It is intended that the open space shall be as close to all residences as possible, with greenways leading to major recreation spaces. Major recreation areas shall be located to serve all residents. The open space is most needed in areas of highest density. 

B. A method of physically delineating private lots from common open space areas shall be provided. Such method may include shrubbery, trees, markers, or other method acceptable to the municipality. 

C. Recreation Land—The Site Capacity Calculations of Section 402 of this ordinance require that a portion of the open space be usable for active recreation. The following standards shall apply to the design of the recreation land: 

1. Areas set aside for active recreation purposes shall be of adequate size and configuration to accommodate the intended use. The National Recreation and Park Association Standards, standards established by a sports governing body, or standards obtained from another credible source shall be used to determine the exact spatial and dimensional requirements needed for a specific type of recreation area or facility. 

2. The recreation land shall not include narrow or irregular pieces of land which are remnants from lotting or the layout of streets and parking areas. 

3. The developer shall be required to improve the recreation land so that it is usable for the intended activity, including necessary facilities and equipment. The proposed improvements, including facilities and equipment, shall be acceptable to the municipality. 

4. The slope of recreation land to be used for active play areas shall not exceed 2 percent. Compliance with this slope requirement may be achieved through regrading, in keeping with applicable natural resource protection standards. 

1. At least one side of the recreation land shall abut a street for a minimum distance of 50 feet. 

2. Recreation land shall not be traversed by utility easements unless said utilities are placed underground and no part of them or their supportive equipment protrudes above ground level. 

D. Open space shall be freely accessible to all residents of the development. 

Section 503 Open Space Performance Bond 

Designated planting and recreation facilities within the open space areas shall be provided by the developer. A performance bond or other securities may be required to cover costs of installation in accordance with the provisions of the subdivision and land development ordinance. 

Section 504 Ownership of Open Space 

Any of the following methods may be used to preserve, own, or maintain open space: condominium, homeowners’ association, dedication in fee simple, dedication of easements, or transfer to a private conservation organization. The following specific requirements are associated with each of the various methods. 

A. Condominium—The open space may be controlled through the use of condominium agreements. Such agreements shall be in conformance with the Pennsylvania Uniform Condominium Act of 1980, as amended. All open space land shall be held as "common element." Such land shall not be eligible for sale to another party except for transfer to another method of ownership permitted under this section, and then only where there is no change in the open space ration. 

B. Homeowners’ Association—The open space may be held in common ownership by a homeowners’ association. This method shall be subject to all of the provisions for homeowners’ associations set forth in Article VII of the Pennsylvania Municipalities Planning Code. 

C. Fee-simple Dedication—The municipality may, but shall not be required to, accept any portion or portions of the open space provided the following conditions are met: 

1. Such land shall be freely accessible to the public. 

2. There shall be no cost to the municipality involved. 

3. The municipality agrees to and has access to maintain such lands. 

4. The open space shall be in an acceptable condition to the municipality at the time of transfer with regard to size, shape, location and improvement. 

D. Dedication of Easements—The municipality or county may accept, but shall not be required to accept, easements to any portion or portions of the open space. In such cases, the land remains in the ownership of the individual, condominium, or homeowners’ association while the easements are held in public ownership. The county shall accept the easements only in accordance with the provisions of Act 442 and county plans. The municipality may accept such easements as it sees fit. In either case, there shall be no cost to the county or municipality for acquisition or maintenance. The municipality may require this method where it seems this is the most appropriate way of preserving land in open space. 

E. Transfer to a Private Conservation Organization—With permission of the municipal officials an owner may transfer either the fee simple title, with appropriate deed restrictions running in favor of the municipality, or easements, to a private, nonprofit organization, among whose purposes is to conserve open space land and/or natural resources provided that the following conditions are met: 

1. The organization is acceptable to the municipal officials and is a bona fide conservation organization with perpetual existence. 

2. The conveyance contains appropriate provision for proper reverter or re-transfer in the event that the organization becomes unwilling or unable to continue carrying out its functions. 

3. A maintenance agreement acceptable to the municipal officials is entered into by the developer and the organization. 

F. Deed Restrictions 

1. Buffer yards as required by this ordinance may be held in the ownership of the individual property owners of residential developments. This form of ownership of open space will be subject to the following requirements: 

a) This form of ownership will be limited to buffer yards. 

b) It may be used only if approved by the municipal officials. 

c) Restrictions meeting municipal specifications must be placed in the deed for each property that has buffer yards within its boundaries. The restrictions shall provide for the continuance of the buffer yard in accordance with the provisions of this ordinance. 

d) It will be clearly stated in the individual deeds that the maintenance responsibility lies with the individual property owner. 

2. For nonresidential uses, buffer yards and areas of natural resource features may be held with the ownership of the entire parcel provided the buffer yards and natural features are deed restricted to ensure their protection and continuance. 

3. In the case of residential developments where all of the units are rental, the open space land may be in the same ownership as that of the development provided that the land is deed restricted to ensure its protection and continuance and that a maintenance agreement suitable to the municipality is provided. 

4. For any of the above options, the municipality may accept, but is not required to accept, an easement to the open space land in the development. 

G. Any property located with the municipality which is subject to a restriction against further subdivision, whether by notation on an approved development plan and/or restriction in a deed, shall not be further subdivided, regardless of an intervening change in zoning classification. 

Section 505 Costs 

Unless otherwise agreed to by the municipality or county, the cost and responsibility of maintaining open space shall be borne by the property owner, condominium association, or homeowners’ association. If the open space is not properly maintained, the municipality may assume responsibility of maintenance and charge the property owner, condominium association, or homeowners’ association fee which covers maintenance costs, administrative costs, and penalties as stipulated in this ordinance.

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