In expansion of the declaration of legislative intent and community development objectives contained in Article I of this chapter, the specific intent of this district is:
A. 
To provide for the Township's fair share of population growth, by permitting high-density development and a variety of detached, semidetached, and attached dwelling types.
B. 
To provide standards that permit orderly and efficient high-density development while preserving and protecting adjacent areas from any negative impacts.
C. 
To promote the sense of neighborhood and promote community identity.
D. 
To encourage walking between buildings, and encourage automobile trips that serve more than one purpose, thereby reducing traffic volume.
E. 
To provide open space and recreation facilities for the benefit of residents of high-density developments.
F. 
To further the general welfare by extending greater opportunities for better and more affordable housing to present and prospective residents of Lower Frederick Township.
G. 
To promote the objectives and policies of the Township Comprehensive Plan.
[Amended 11-8-2000 by Ord. No. 00-04]
In the R-4 High-Density Residential District, a building may be erected, altered or used, and a lot may be used or occupied, for any of the following uses and no other:
A. 
Any mix of the following residential dwelling types, according to the densities permitted in § 170-61A below:
(1) 
Single-family detached dwelling.
(2) 
Lot line house dwelling.
(3) 
Village house dwelling.
(4) 
Patio house dwelling.
(5) 
Single-family semidetached dwelling.
(6) 
Two-family detached dwelling.
(7) 
The following dwelling types are permitted on tracts with a minimum of two acres, excluding rights-of-way of existing roads:
(a) 
Two-family semidetached dwelling.
(b) 
Atrium house dwelling.
(c) 
Townhouse dwelling.
B. 
Open space uses, primarily passive in nature, including wildlife sanctuary, forest preserve, nature center, and similar uses.
C. 
Game farm, fish hatchery, hunting or fishing preserve; or similar uses designed for the protection or propagation of wildlife.
D. 
Parks and recreation areas in compliance with the standards and criteria of Article XIII, Institutional and Recreational Overlay District, when approved by the Board of Supervisors.
E. 
Home occupation, by special exception and in compliance with § 170-25 of this chapter.
F. 
Accessory uses. Accessory uses shall be permitted on the same lot with and customarily incidental to any permitted use, in compliance with § 170-24, Accessory uses, of this chapter.
G. 
Government uses, public utility facility.
H. 
Residential conversion to not more than two dwelling units of any single-family detached dwelling that existed as of the date of adoption of this chapter, provided that the dimensional and development regulations for a two-family detached dwelling and all other zoning requirements are met.
[Amended 10-3-2023 by Ord. No. 2023-03]
A. 
Density shall be calculated in compliance with the standards listed below. Maximum tract density shall be subject to further modification by the environmental adjustment factors in § 170-41 of this chapter.
(1) 
Single-family detached dwellings: three dwelling units per acre.
(2) 
Lot line and village house dwellings: four dwelling units per acre.
(3) 
Patio house dwellings: five dwelling units per acre.
(4) 
Single-family semidetached and two-family detached dwellings: six dwelling units per acre.
(5) 
Two-family semidetached, atrium house, and townhouse dwellings: six dwelling units per acre.
B. 
Minimum buildable area for each building lot shall be equal to the minimum lot size specified in Table 170-61C below or 21,780 square feet, whichever is smaller.
C. 
The minimum lot area, minimum lot width, maximum building coverage, maximum impervious surface coverage, and minimum front, side and rear yard setbacks required for each permitted use in the R-4 High-Density Residential District are as prescribed in Table 170-61.C herein.
Table 170-61C
Dimensional Regulations: R-4 High-Density Residential District
Dwelling/Use Type
Minimum Lot Area
(square feet)
Minimum Lot Width
(feet)
Maximum Building Coverage
(%)
Maximum Impervious Surface Coverage
(% of lot area)
Minimum Front Yard
(feet)
Minimum Side Yard
(feet)
Minimum Rear Yard
(feet)
Single-family detached
10,000
80
14
20
25
15/
30
Lot line house
7,000
60
30
40
25
30 (one only)
30
Village house
6,200
55
20
30
15
10
30
Patio house
4,500
45
30
45
25
10
0
Single-family semidetached
5,000 per du
40 per du
25
40
25
12 (one only)
30
Two-family detached
5,000 per du
40 per du
20
35
25
15
30
Two-family semidetached
3,000 per du
30 per du
20
40
25
20 (one only)
30
Atrium house
2,500 per du
40 per du
50
65
20
10 (end only)
0
Townhouse
2,500 per du
20 per du
50
65
20
15 (end only)
25
All other uses (except parks and recreation areas)
43,560 (1 acre)
150
20
50
30
20
30
D. 
Access to a public street. As an exception to the requirements of § 170-11 of this chapter, each and every lot in the R-4 District shall abut a public street at the ultimate right-of-way line for at least 50 feet or the minimum lot width requirement for the specific dwelling/use type, whichever is smaller, and said frontage must be usable for purposes of ingress and egress to the lot, subject further to the design requirements of § 170-63 of this chapter.
E. 
Additional setback regulations.
(1) 
A lot with multiple street frontages shall have a front yard setback along each frontage.
(2) 
If a standard building line has been established by previous development on adjoining streets, and it is less than the minimum front yard setback required for that dwelling type as set forth above, the minimum front yard setback for a new development shall be the average front yard setback of existing principal buildings within 500 feet to either side of the proposed development.
(3) 
Lot line house. Only one side yard is required for lot line houses. Unless a side yard having a minimum setback of five feet is provided for the second side yard, a five-foot-wide maintenance easement shall be provided along the side lot line. Minimum distance between a lot line house and another dwelling shall be 30 feet.
(4) 
Two side yard setbacks are required for single-family and two-family detached dwellings, and one side yard setback is required for single-family and two-family semidetached dwellings.
(5) 
Minimum distance between buildings containing atrium or townhouse dwellings shall be 40 feet.
F. 
Zoning district boundary setback. A minimum setback of 50 feet is required between any semidetached or attached principal building in the R-4 High-Density Residential District and any Township boundary or any boundary of a residential zoning district with a maximum permitted density of two units per acre or lower. This setback may be part of a required yard area and shall include landscaping and/or berming according to the provisions of Chapter 145, Subdivision and Land Development.
G. 
Unless specifically regulated elsewhere in this chapter, the maximum height for all accessory buildings and structures is 15 feet and is 35 feet for all other buildings and structures. (See § 170-24 and § 170-32 for additional height regulations).
H. 
Parking area setback. A minimum thirty-foot setback shall be required between any parking area of eight or more spaces and any side or rear lot line or tract boundary. This parking area setback may be part of a zoning district boundary or buffer yard. If the parking area extends over or is shared/used by two or more lots, the setback shall not be required from the common lot line(s) of these lots.
I. 
Maximum length of attached dwellings. No more than four atrium houses or eight townhouses are permitted within one building. The length of any single building or connected buildings containing residential dwellings shall not exceed 160 feet.
J. 
Subdivision and land development. All applicants seeking subdivision and/or land development approval shall comply with and follow the requirements of § 170-41, Environmental adjustment factors, to determine the development capacity of the site.
K. 
Only one principal use shall be allowed on a lot.
A. 
All development in the R-4 High-Density Residential District shall be served by public water and sewer.
B. 
All development shall comply with the provisions of Chapter 145, Subdivision and Land Development.
C. 
All development shall comply with the parking requirements of Article XVII of this chapter.
D. 
Open space. All developments in the R-4 High-Density Residential District with two-family semidetached, atrium house, and/or townhouse units, and with 16 units or more, shall have required permanent open space, according to the following standards:
(1) 
Amount of open space.
(a) 
The amount of the open space shall be as follows:
Dwelling Type
Required Open Space
Two-family semidetached dwelling
15% of tract area
Atrium house dwelling
25% of tract area
Townhouse dwelling
35% of tract area
(b) 
For mixed dwelling type developments, the open space shall be calculated according to the acreage for each particular dwelling type. For example, a development with half atrium house dwellings and half townhouse dwellings shall be required to have 30% open space. A development with half village house dwellings and half townhouse dwellings shall be required to have 17.5% open space.
(2) 
Ownership. The open space shall be conveyed in accordance with one or more of the following methods, as approved by the Board of Supervisors:
(a) 
Dedication in fee-simple to Lower Frederick Township, at the option of the Board of Supervisors.
(b) 
Conveyance of title (including beneficial ownership) to: an association, condominium, conservancy, corporation, funded community trust, individual or other legal entity for maintenance purposes.
(c) 
Fee-simple ownership with conveyance of restrictive covenants, conservation easements, or other suitable legal device to: Lower Frederick Township, an association, condominium, conservancy, corporation, funded community trust, individual or other legal entity for maintenance purposes. The terms of such instrument of conveyance shall include provisions to the Township for guaranteeing the continued use of such land for open space and recreation.
(3) 
Design. The open space shall not include required setback areas, shall have adequate access, and shall be designed in one or more of the following ways, as approved by the Board of Supervisors:
(a) 
Buffer area, to buffer the impact of new development from existing, adjacent development.
(b) 
Preservation of natural features, such as woodlands, stream valleys, wetlands, or steep slopes.
(c) 
Central green or parkway, which shall be located in a central position in the neighborhood, surrounded by streets and/or building lots on at least three sides, and designed and landscaped as a space for common neighborhood use.
(d) 
Up to 50% of the area of a stormwater basin may be counted towards the open space requirement, according to the following criteria:
[1] 
The slope of any part of the basin shall not exceed 5:1.
[2] 
The basin shall be designed to incorporate curvilinear features that blend with the surrounding topography.
[3] 
The basin and surrounding areas shall be planted with a variety of cover vegetation such as lawn grass or naturalized plantings specifically suited for stormwater basins. Plantings shall not interfere with the proper function of the basin.
A. 
No access for two-family semidetached, atrium house, or townhouse dwellings shall be from existing streets, except when permitted by the Board of Supervisors. All access to these dwelling types shall be from interior roads or common driveways which serve four or more units.
B. 
Common parking areas for two-family semidetached, atrium house and townhouse dwelling developments shall be separated from the street by a landscaped buffer strip of at least five feet in depth, and shall be limited to two access points on any street.
C. 
The siting of all required parking spaces in the side and rear yard areas of the lots is strongly encouraged. If an alley exists to the rear of the lot, parking off the alley is strongly encouraged. The use of shared or common driveways is also encouraged.
D. 
If the front yard setback includes parking, there shall be a minimum five-foot buffer between the end of the driveway or parking area and the dwelling unit (except in case of a driveway leading to a garage or carport). The buffer area shall be landscaped and shall not be paved.
E. 
Parking facilities for three or more vehicles provided entirely on one lot shall be designed to permit at least two vehicles to proceed to and from a parking space provided for them without requiring the moving of any other vehicles.
F. 
Parking shall not interfere with driveways, accessways, sidewalks, or pedestrian walkways.
G. 
The facades of every second atrium or townhouse dwelling shall be offset by a minimum of four feet.[1]
[1]
Editor's Note: Original Article 9, R-5 Multifamily Mobile Home Park District, as amended, which immediately followed this subsection, was repealed 7-5-2005 by Ord. No. 05-08.