A. 
In addition to the purposes and community development objectives discussed in Article I, the intent of this article is to allow lands encumbered by natural, scenic, historic and cultural resources to be developed in a more site-sensitive manner than is generally possible through conventional subdivisions. The resulting residential development shall preserve the open, rural character of the Township, maintain the quality of the existing scenic landscape, and cause the least possible disturbance to environmentally sensitive resources of the land and result in the greatest possible retention of open space for the use and enjoyment of the residents of the development and the aesthetic benefit of the Township as a whole in a manner which is consistent with: the Township Open Space, Recreation, and Environmental Resources Plan; the Township Comprehensive Plan; the Chester County Comprehensive Plan; and Pennsylvania Municipalities Planning Code.[1]
[1]
Editor's Note: 53 P.S. § 10101 et seq.
B. 
Such environmentally sensitive and open space-oriented developments can be achieved through a combination of more concentrated development, more efficient use of infrastructure and creative lot design. To encourage the use of this development option, a minimal density bonus shall be granted for development that uses this option. The large tract option was utilized for the development of The Preserve at Squire Cheyney and the small tract option for the development of Sage Hill.
A. 
To be eligible for development of a small tract cluster residential development, the tract must at a minimum:
(1) 
Be at least 25 acres in total site area; and
(2) 
Consist of either:
(a) 
A single parcel of land; or
(b) 
Multiple contiguous parcels undivided by roads, railroad rights-of-way or other significant obstructions that effectively divide the site. In the case of multiple contiguous parcels, all applicable parcels shall be developed according to a single plan and with common authority and common responsibility. The applicant shall submit evidence of an agreement between all owners of included parcels demonstrating binding commitment to common development of the parcels; and
(3) 
Be located within the R-1 or R-2 districts; and
(4) 
Be served by public water and either a community or public sanitary sewage disposal system.
B. 
In addition to complying with § 155-1201A(3) and (4), to be eligible for development of a large tract cluster residential development, the tract must at a minimum:
(1) 
Comprise a minimum of 70 acres in tract area; and
(2) 
Consist of either:
(a) 
A single parcel of land; or
(b) 
Multiple noncontiguous parcels directly adjacent to Township-owned open space lands and identified as scenic lands intended to preserve the scenic character of the Township from adjacent roadways and properties as defined by the Thornbury Township Open Space, Recreation and Environmental Resources Plan and are within 100 feet of each other. All applicable parcels shall be developed according to a single plan and with common authority and common responsibility. The applicant shall submit evidence of an agreement between all owners of included parcels demonstrating binding commitment to common development of the parcels; and
(3) 
Contain protected areas, moderate slopes and woodland areas, which comprise a combined area greater than or equal to 25% of the total tract area.
(4) 
Be identified by the Township Open Space, Recreation and Environmental Resources Plan as scenic lands and contain historic resources and be listed on the State Inventory of Historic Places.
A. 
The following uses are permitted in both a small and large tract cluster residential development:
(1) 
Single-family detached dwellings.
(2) 
Noncommercial outdoor recreation uses.
(3) 
Publicly owned recreation uses.
(4) 
Protected areas.
(5) 
Stormwater management facilities.
(6) 
Areas and structures for the land application and conveyance of sewage.
B. 
In addition to those uses listed in § 155-1202A the development of large tract cluster residential development is eligible for the following additional uses:
(1) 
Municipal uses.
(2) 
Scenic lands.
(3) 
Trails for nonmotorized use.
For any development under this article, the maximum permitted number of dwelling units shall be calculated by multiplying the number of units allowed under the provisions of § 155-1409, Gross density, by 1.20.
A. 
The following net density and area regulations apply to all small tract cluster residential developments:
(1) 
Common open space.
(a) 
Not less than 60% of the total tract area must be designated on the plan as common open space and held in a tract or tracts separate from the development area.
(b) 
Not less than 15% or five acres (whichever is greater) of common open space areas must be suitable for active recreational use and free of the following constraints:
[1] 
Protected areas; and
[2] 
Areas used for land application of sewage.
(2) 
Development area.
(a) 
The area(s) of the tract that will not be designated as part of the common open space area must be designated on the plan as development area(s). Development areas are all areas not designated as common open space and include (but are not limited to) building areas, yards, driveways and roads.
(b) 
Within a development area, single-family dwellings may be arranged so as to provide for individual lots for each unit or may be arranged as rental units or condominiums. Sufficient yard areas shall be set aside [see dimensional standards in § 155-1205B(1)] and designated on the plan so that throughout the development the maximum net residential density shall not exceed four units per acre.
(c) 
Within any development area that is developed as rental or condominium units rather than in individual lots, the remaining area within the development area (that not containing structures, roads, driveways, etc.) shall be designated local open space. Local open space shall remain separate from common open space, and its use shall be primarily for residents of the development area in which it is located.
(d) 
Uses within local open space areas shall be limited to yard area, landscape areas and walkways. There shall be a minimum of 20 feet between all buildings within development areas and the outer edge of adjacent local open space.
B. 
The following net density and area regulations apply to all large tract cluster residential developments:
(1) 
Common open space.
(a) 
Not less than 50% of the net tract area must be designated on the plan as common open space and held in a tract or tracts separate from the development area.
(b) 
Conservation lots that contain and preserve historic structures that are either listed on the National Register of Historic Places (NRHP) or are eligible for inclusion on the NRHP may be counted toward the required common open space.
(c) 
A minimum of 15% of the open space shall be suitable for active recreational uses.
(2) 
Development area. The area(s) of the tract that will not be designated as part of the common open space area must be designated on the plan as development area(s). Development areas are all areas not designated as common open space and include (but are not limited to) building areas, yards, driveways and roads.
(a) 
Within a development area, single-family dwellings shall be arranged so as to provide for individual lots for each unit. Sufficient yard areas shall be set aside [see dimensional standards in § 155-1205B(2)] and designated on the plan, so that throughout the development the maximum net residential density shall not exceed four units per acre of the total tract area.
(b) 
There shall be a minimum of 20 feet between all buildings within development areas and adjacent Township open space.
A. 
Site design principles. The location of common open space, dwellings and site improvements shall be in response to the findings of the site analysis plan required under Chapter 115, Subdivision and Land Development, § 115-29C(11). The following standards shall apply during the siting process:
(1) 
For both small and large tract cluster residential developments, areas designated as common open space shall be configured so as to:
(a) 
Minimize negative impacts of development on the tract and scenic roads;
(b) 
Maximize conservation of site features identified as having particular conservation, historical, or recreational value, including: steep slopes, floodplains, watercourses, wetlands, high groundwater areas, mature trees, woodlands, hedgerows, fence lines, historic sites or structures, historic road or other transport traces, paths and trails, and other noted landscape features;
(c) 
Serve as buffer areas between clustered dwellings and adjacent tracts; and
(d) 
Maximize views of the common open space from off-site tracts, roads, streets and highways.
(2) 
For both small and large tract cluster residential developments, dwellings and accessory buildings shall be configured so as to:
(a) 
Be located outside of protected areas and natural drainage swales; and
(b) 
Be located outside of broad, open vistas; and
(c) 
Provide maximum views of and access to open space by residents of proposed dwellings.
(3) 
In addition to the standards listed under § 155-1205A(2); dwellings and accessory buildings for a small tract cluster residential developments shall be configured so as to be:
(a) 
Situated below ridge line elevations to preserve existing vistas. To achieve this objective, dwellings and accessory buildings should be sited entirely below the elevation of the nearest ridgeline whenever possible. Where the applicant claims that dwellings or accessory buildings cannot be situated below the ridgeline, it shall be the burden of the applicant to demonstrate why not and how the proposed design creates the minimum possible disturbance of views of the ridgeline per the requirements of § 155-1205B(1)(b)[1].
B. 
Dimensional standards.
(1) 
The following dimensional standards are required for any small tract cluster residential development:
(a) 
All dwelling units within a small tract must be set back a minimum of 100 feet from the nearest tract property line, except as follows:
[1] 
Where preexisting natural features of the subject property, including, but not limited to, woodland areas, changes in topography, hedgerows or other site characteristics, result in the dwelling unit being completely visually screened from the adjacent property, this setback may be reduced to 50 feet.
[2] 
Where preexisting natural features of the subject property, including, but not limited to, hedgerows or partially wooded areas, significantly screen dwelling unit(s) from the adjacent property but do not create a complete visual screen, this setback may be reduced to 75 feet.
[3] 
The determination of whether the site characteristic in question results in complete visual screening or significant screening is at the sole discretion of the Board of Supervisors.
(b) 
Building height shall be limited to three stories, not to exceed 30 feet.
[1] 
To the extent that any portion of a structure must be located above a ridgeline elevation, such siting shall be contingent upon the submission and approval by the Board of Supervisors of a plan for the mitigation of such ridgeline impacts. Such plans shall identify the locations and dimensions of the proposed structure(s) the architectural style proposed and shall demonstrate how the structure(s) shall be effectively screened from adjacent tracts through screening and/or designed to minimize disruption of views of the ridgeline.
(c) 
No single structure shall be more than 100 feet in length in any direction.
(d) 
The minimum required distance between buildings shall be 15 feet.
(e) 
All buildings shall be set back at least 20 feet from the curb of any internal access road.
(f) 
All buildings shall be set back at least 10 feet from the edge of any shared parking area, except in the case of adjacent driveways, for which no setback shall be required.
(g) 
Where common open space is designated as separate, noncontiguous parcels, no single parcel shall consist of less than one acre in area. No single area or portion of an area designated as common open space shall be counted toward the minimum required open space wherever such area or portion of area is less than 100 feet in width (all of which shall be contained on the subject property) except in the case of a trail corridor designated in the Thornbury Township Open Space, Recreation, and Environmental Resources Plan or other linkage between two larger, noncontiguous, open space areas.
(h) 
Any parcel within a cluster development that could qualify for further subdivision, including any common open space parcel, shall be restricted from further subdivision or land development by deed restriction, conservation easement or other agreement in a form acceptable to the Township and duly recorded in the office of the Recorder of Deeds of Chester County and shall be noted on the face of the record plan. Any such mechanism shall be structured in a manner that would require the agreement of both the Township and the homeowners' association or like organization in order to abolish it in the future.
(2) 
The following dimensional standards are required for any large tract cluster residential development:
(a) 
All dwelling units within a tract must be set back a minimum of 40 feet from the nearest tract property line, except as follows:
[1] 
Where proposed development is adjacent to existing Township open space, this setback may be reduced to 20 feet.
[2] 
The Board of Supervisors may require additional landscaping to mitigate the impact of the development on the surrounding community.
(b) 
Building height shall be limited to three stories, not to exceed 35 feet.
(c) 
No single structure shall be more than 100 feet in length in any direction.
(d) 
The minimum required distance between buildings shall be 20 feet and the required side yard setback shall be 10 feet.
(e) 
All buildings shall be set back at least 20 feet from the road right-of-way of proposed roadways.
(f) 
The minimum total lot size shall be 20,000 square feet.
(g) 
The maximum impervious surface area for any lot shall be 35% of the total lot area. Additionally, no more than 20% of the total tract area shall be of impervious surfaces.
(h) 
Where open space is designated as separate, noncontiguous parcels, no single parcel shall consist of less than one acre in area.
(i) 
Any parcel within a scenic open space residential cluster development that could qualify for further subdivision, including any open space parcel, shall be restricted from further subdivision or land development by deed restriction, conservation easement or other agreement in a form acceptable to the Township and duly recorded in the office of the Recorder of Deeds of Chester County and shall be noted on the face of the record plan. Any such mechanism shall be structured in a manner that would require the agreement of both the Township and the homeowners' association or like organization in order to abolish it in the future.
(3) 
Other applicable standards:
(a) 
Natural Resource Protections, per Article XIV.
(b) 
Signs, per Article XVII.
(c) 
Off-Street Parking and Loading, per Article XVIII.
(d) 
Lighting, per § 155-1505.
A. 
Permitted uses within common open space areas, for both small and large tract cluster residential developments, shall be as follows:
(1) 
Natural area, including, but not limited to, steep slopes areas, woodland, meadow, wetlands, stream, etc.;
(2) 
Lawn;
(3) 
Outdoor recreation area, either active or passive, for the use of the residents of the development;
(4) 
Agriculture, subject to the ownership mechanism, procedures and limitations under § 155-1207B(5);
B. 
Additional permitted uses within common open space areas for small tract cluster residential developments include:
(1) 
Community or public sewage treatment facility involving land disposal and groundwater recharge facilities, but excluding buildings and other aboveground structures associated with such facilities.
C. 
Additional permitted uses within common open space areas for large tract cluster residential developments include:
(1) 
Community or public sewage conveyance and treatment facility involving land disposal and groundwater recharge facilities, as well, as buildings and other aboveground structures associated with such facilities, including a sewage pumping station.
(2) 
Areas utilized for stormwater management and groundwater infiltration. The maximum combined areas of stormwater management facilities and sanitary sewer facilities shall not exceed 50% of the required open space areas.
(3) 
Historic structures, as defined within the Open Space, Recreation and Environmental Resources Plan, and associated lot area for the purpose of preserving historic resources.
A. 
The subdivision and/or land development plan submission shall include documents creating and governing a property owner's organization and containing the declarations of covenants, restrictions, easements, charges and liens deemed necessary to own and maintain the common open space area(s), local open space area(s) and any recreation areas within the cluster development.
B. 
Ownership options. Areas to be preserved in common open space shall be held either individually or collectively using the following methods of ownership:
(1) 
Homeowners' association. The common open space areas and their facilities may be held in common ownership by a homeowners' association. The association shall be formed and operated in accordance with the provisions of § 155-1207C.
(2) 
Condominium. The common open space areas and their facilities may be held as common element under a condominium agreement. Such agreement shall be in conformance with the Uniform Condominium Act.[1]
[1]
Editor's Note: See 68 Pa.C.S.A. § 3101 et seq.
(3) 
Fee simple dedication to the Township. The Board of Supervisors may consider open space lands and their facilities for dedication for public use at the time of application for cluster development approval. The Township has neither the obligation to accept such property, nor the need to require dedication of common property as a condition for approval.
(4) 
Dedication of easements. Easements within common open space areas along such unique natural features as water bodies may be offered to the Township for public use or to a private conservancy. Title to such lands shall remain in ownership by the homeowners' association or condominium agreement.
(5) 
Lease option. To encourage the retention of agricultural lands, the Township, homeowners' association, or the condominium agreement may permit all or portions of the open space lands to be leased back to a farmer. Approval of the lease-back option shall be conditioned on appropriate agreements between the title holder and the farmer concerning permitted farming practices and use of land in the event that farming practices cease, in addition to the requirements of § 155-1207C.
C. 
Homeowners' association regulations. In addition to the foregoing, the following minimum essential provisions shall be identified with respect to such organization:
(1) 
Powers and duties in maintaining and administering open space, recreational facilities and supplementary project facilities such as light fixtures, refuse stations, etc.
(2) 
Powers and duties in administering and enforcing all covenants and restrictions and in the levying, collecting and disbursing of assessments and charges.
(3) 
Membership and voting rights.
(4) 
Rights and duties of the Township of Thornbury, members of the organization and residents of the development in the event of a breach of the covenants and restrictions.
(5) 
If such organization is abandoned or abolished or if such organization desires to dispose of the common open space and recreation areas, said open space recreation areas shall be first offered for dedication to the Township of Thornbury at no cost to the Township before it is otherwise disposed of. The Township may refuse to accept such dedication and elect, as provided in the following subsection, to maintain the open space, with all costs of such maintenance being paid ratably by the residents of the development.
(6) 
In the event that the organization established to own and maintain common open space, or any successor organization, shall at any time after establishment of the development fail to maintain the common open space in reasonable order and condition in accordance with the recorded plan, the Board may proceed in a manner similar to that provided in Section 705(f)(2) of the Pennsylvania Municipalities Planning Code[2] to demand that the deficiencies of maintenance be corrected or that the Township will enter upon and maintain common open space.
(a) 
The Township may continue to maintain such open space, as further provided in that section of the Pennsylvania Municipalities Planning Code,[3] until an organization is established by the residents of the development which the Board finds is ready and able to maintain such common open space. The cost of such maintenance by the Township shall be assessed ratably against the properties within the development that have a right of enjoyment of the common open space and shall become a lien on said properties. The Township, at the time of entering upon said common open space for the purpose of maintenance, shall file a notice of lien in the Chester County Office of the Prothonotary upon the properties affected by the lien within the development.
[3]
Editor's Note: 53 P.S. § 10101 et seq.
[2]
Editor's Note: 53 P.S. § 107(f)(2).