Bristol Township, PA Accessory Structures: ADU Rules (2026)

Use G3 in § 205-16G(3) of the Bristol Township Code defines an accessory apartment as a separate dwelling unit subordinate in size to the principal single-family detached dwelling unit. It can be contained in the principal residence or in an accessory building such as a detached garage, so both a basement or upstairs apartment and a garage apartment fall under the same standards.

It is not a by-right use. In the R-1 District, § 205-22B lists Accessory Apartment among the uses permitted by special exception, authorized by the Zoning Hearing Board under the standards in § 205-187. The R-2 and R-3 permitted-use lists carry the same entry.

The size limits are in subsection (a). Not more than 30% of the total floor area of the principal residence shall be occupied by the accessory apartment, and if the apartment is located in an accessory building, the maximum floor area shall be 650 square feet. Subsection (b) allows not more than one accessory apartment per lot. Under (c) the lot must conform to the minimum lot area requirement for Use A1 Single-Family Detached Dwelling in the district, and under (d) the dwelling or accessory building must meet the minimum yard requirements for Use A1.

Appearance rules follow. The principal residence must maintain the appearance of a detached dwelling with a single front entrance; exterior stairways and fire escapes go on the rear wall in preference to either side wall and in no case on a front wall or a side wall facing a street. Each dwelling unit needs separate cooking, sleeping, living and bathroom facilities, trash receptacles shall not be visible from the street or abutting properties except on scheduled pickup days, and septic systems must be approved by the Bucks County Department of Health. Parking under § 205-120 is the required parking for the principal dwelling plus one additional off-street space per bedroom in the accessory apartment.