Promote a detailed analysis of development parcels so as to locate and coordinate appropriate areas for development and for conservation;

Avoid development that could cause inefficient patterns of development;

Encourage a blend of recreation areas and a mix of housing at a medium density to serve various age groups and types of housing;

Provide for reasonably safe and convenient pedestrian, bicycle and vehicle circulation, with an emphasis on connecting residential and recreational areas;

Provide greater design flexibility and efficiency in the siting of homes, services and infrastructure, including the opportunity to reduce the length of streets and utility facilities;

Preserve rural characteristics through the permanent preservation of meaningful open space and sensitive natural resources;

Encourage the creation of a sense of place and community spirit;

Promote the goals and objectives of the Lower Allen Township Comprehensive Plan Update, 2006, as amended;

Make efficient use of available public water and sewer services and other infrastructure; and

Avoid excessive improvement costs and future Township maintenance costs for each new home by minimizing the amount of street and utility length per home.

The OSD Overlay District applies to R-1 Single-Family Established Residential and R-2 Single-Family Rural Residential Zoning Districts.

OSD developments are a permitted use by right in the R-1 and R-2 Zoning Districts.

For the purposes of this article, the words "parcel" or "lot," whether singular or plural, shall encompass planned community units under the Pennsylvania Uniform Planned Community Act, 68 Pa.C.S.A. § 5101 et seq., as amended, and condominium units under the Pennsylvania Uniform Condominium Act, 68 Pa.C.S.A. § 3101 et seq., as amended, and the lot area, lot width and yard standards of this article shall apply to each such planned community unit or condominium unit as if each unit constituted a parcel or lot.

A minimum tract size of five acres is required for an OSD development.

Each residential lot shall be within 300 feet walking distance of either public recreation land or common open space.

All proposed development within any OSD shall be served by either public water or suitable private wells. If water supply other than public water is proposed, applicant shall provide a hydrogeologic study demonstrating the availability of adequate water supply. The study shall be submitted with the preliminary plan.

All proposed development within any OSD shall be served by either public sewer or a community sewage disposal system.

Traffic from an OSD of 20 acres or more shall have access to a major collector road, a minor arterial road or a local road, as identified in the Township Comprehensive Plan Update, 2006, as amended. Primary access from an OSD of 20 acres or more from a minor Township road shall not be permitted. Where primary access to an OSD of 20 acres or more is via a major collector road or a local road, the primary route of travel from the OSD to a principal arterial shall be identified. This primary route of travel shall not contain deficiencies identified in the Township Comprehensive Plan Update, 2006, as amended.

Single-family detached and side-by-side twin dwelling unit lots are permitted to front only minor Township or local streets. All other permitted uses are permitted to front on minor Township, local or major collector street.

All OSD developments shall include provisions for constructing trails within and through the development.

Single-family detached dwellings.

Townhouses.

Side-by-side twin dwellings.

Publicly owned recreation uses; recreation uses and open space owned by a property owners association.

Nature preserves.

Maximum density for a OSD shall be determined as follows:

The densities achieved in Subsection A may be increased by not more than two DU per acre, resulting in a maximum R-1 density of eight DU per acre and a maximum R-2 density of four DU per acre by applying the following methodology:

For single-family detached dwellings:

For side-by-side twin dwelling:

For townhouse dwelling units:

For all other permitted uses:

On a multiple frontage lot, a front yard shall be provided abutting each street frontage.

For single-family detached, side-by-side twin and townhouse dwellings:

For single-family detached dwelling: minimum side yards shall total no less than 15 feet, with no one side less than five feet, in width. On a corner lot, two side yards shall be provided along the interior lot lines.

For side-by-side twin dwellings:

For townhouse dwellings:

For all other permitted uses, refer to the requirements in the underlying zoning district.

An unenclosed porch, deck or patio may intrude into a required front, side or rear yard a maximum of 50% of the required setback or 10 feet, whichever is less.

Chimneys, roof overhangs, rain gutters, building footings, window wells and similar features may intrude up to two feet into a required setback.

Detached accessory buildings shall be set back a minimum of five feet from a side or rear lot line. Accessory buildings shall not be permitted within a front yard.

A minimum percentage of 60% of total allowable dwelling units within any OSD must be detached single-family dwellings.

For townhouse dwelling units:

In addition to required public recreation land, a minimum of 25% of the gross area of an OSD development shall be retained as common open space reserved for passive recreational use.

A minimum of 50% of the designated common open space shall not be regraded as part of development of the site.

Common open space shall be available for use by residents of the OSD and their guests free of charge, except for areas of nonintensive agriculture, horticulture, floriculture or silviculture. An annual maintenance fee assessed to all property owners for maintenance of common open space shall not be considered a charge for use of the space.

Common open space may be made available for use by the general public. This shall not be cause to reduce the requirements for dedication of public recreation land.

A pedestrian access and trail construction plan shall be required to provide accessibility to the common open space.

Commercial uses shall not be permitted in common open space, except for community events approved by the owner of the common open space.

Any area designated as common open space shall be no smaller than four times the area of the smallest residential lot within the OSD development, except for designated trails.

Applicant must supply documentation showing proposed plan for ownership and perpetual maintenance and protection of common open space (COS). Available methods are as follows:

A conservation easement shall be provided to ensure that all common open space shall remain open in perpetuity.