The purposes of this district are to provide for medium- to medium-high-density dwelling units, including single-family detached, twins, townhouses, duplexes and apartments, to preserve existing residential development and open space and to provide for and regulate certain nonresidential uses permitted only by special exception.
Land, buildings or premises shall be used by right for only one or more of the following uses:
A. 
All uses permitted by right in the R-1 Residential District.
B. 
Single-family attached dwelling (townhouses).
C. 
Two-family detached dwelling (detached duplex).
The following uses shall be permitted by special exception only, subject to the applicable provisions of Articles XIX, Procedures and Standards for Special Exceptions, and XXIV, Zoning Hearing Board:
A. 
Religious use, including accessory dwelling, subject to § 185-1811.
B. 
Apartments, subject to § 185-404E.
C. 
Educational use, subject to § 185-1906, excluding commercial educational use as defined in Article II.
D. 
Conversion, subject to § 185-1903.
E. 
Retail store operated by a person residing in the same building wherein the store is operated.
All accessory uses permitted in the R-1 Residential District.
Unless specifically stated otherwise, the following shall be minimum requirements:
A. 
Single-family detached dwelling:
Standard
Size
Lot size
4,000 square feet
Lot width
40 feet
Front yard
20 feet, which may be reduced to 15 feet on the long side of a corner lot
Side yards
15 feet aggregate and 5 feet minimum
Rear yard
25 feet, minimum
Building coverage
45%, maximum
Impervious surface
60%, maximum
Height
40 feet or 3 stories, maximum
B. 
Single-family semidetached dwelling (twin):
Standard
Size
Lot size
3,000 square feet
Lot width
30 feet
Front yard
20 feet, which may be reduced to 15 feet on the long side of a corner lot
Side yards
10 feet
Rear yard
25 feet
Building coverage
60%, maximum
Impervious surface
75%, maximum
Height
40 feet or 3 stories, maximum
C. 
Two-family detached dwelling (detached duplex):
Standard
Size
Lot size
4,500 square feet
Lot width
45 feet
Front yard
20 feet, which may be reduced to 10 feet on the long side of a corner lot
Side yards
10 feet aggregate and 5 feet minimum
Rear yard
25 feet
Building coverage
50%, maximum
Impervious surface
65%, maximum
Height
35 feet or 2 stories, maximum
D. 
Single-family attached dwelling (townhouse):
Standard
Size
Lot size
1,800 square feet
Lot width
18 feet
Front yard
20 feet, which may be reduced to 10 feet on the long side of a corner lot
Side yards
10 feet at ends of row; 20 feet where an access driveway is required
Rear yard
25 feet
Building coverage
65%, maximum
Impervious surface
80%, maximum
Height
40 feet or 3 stories, maximum
E. 
Apartment building:
Standard
Size
Lot size
1,500 square feet per dwelling unit
Lot width
100 feet
Front yard
20 feet for front street and long side of corner lot
Side yards
30 feet aggregate
Rear yard
25 feet
Building coverage
45%, maximum
Impervious surface
60%, maximum
Open space
15% of lot area
Height
45 feet or 3 stories, maximum