Accessory Structures in Philadelphia, PA (2026)
9 verified accessory structures rules for Philadelphia, Pennsylvania, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Philadelphia permits accessory dwelling units (ADUs) only on lots in the RSA-5 or CMX-1 base zoning districts (and certain overlay districts), under Zoning Code Section 14-604(11). The ADU must be inside the principal building or inside a detached accessory building (such as a detached garage) that already existed as of the Code's effective date, be no larger than 800 square feet, be limited to one per lot, and the owner must occupy either the principal or accessory unit.
ADUs allowed by-right in RSA-5 and CMX-1 only
Heavy RestrictionsPhiladelphia L&I Accessory Dwelling Unit Checklist (PZ_004_INF, Rev 3.2022), Step 3 - Additional Code Requirements; implementing Phila. Zoning Code Sec. 14-604(11)
Location: ADUs must be located within the principal building or within a detached accessory building, such as detached garages, that are in existence as of the effective date of this Zoning Code. Maximum of One ADU: No more than one accessory dwelling unit is allowed per lot. Floor Area of ADU: The floor area of the ADU may not exceed 800 square feet, OR the ADU is within a historic structure a...
ADU Permits
Philadelphia permits ADUs under Title 14 (Zoning Code) where the underlying district allows. Most RSA-5 and RSD-3 rowhouse zones allow ADUs by right. Permits are processed through Licenses and Inspections. Lot size, setbacks, and building code compliance under Title 4 apply.
Philadelphia ADU Permits
Some RestrictionsADU Impact Fees
Philadelphia does not charge development impact fees on residential ADUs. The city charges only standard permit and plan-review fees through L+I. Philadelphia Water Department charges connection fees only where new service is installed. PA does not authorize municipal school impact fees.
Philadelphia ADU Impact Fees
Few RestrictionsADU Owner Occupancy
Philadelphia does not require owner-occupancy for ADUs under Title 14. The city imposes no residency restriction on ADU property owners. HOAs governed by the Pennsylvania Uniform Planned Community Act (UPCA) may impose owner-occupancy through covenants, subject to reasonableness requirements.
Philadelphia ADU Owner Occupancy
Few RestrictionsADU Rental Restrictions
Philadelphia requires a rental license for all rental units including ADUs under Property Maintenance Code Section PM-102.1. Pennsylvania preempts municipal rent control. Short-term rentals require separate Visit Philadelphia STR license. ADU long-term rentals are unrestricted in lease terms but must maintain rental license.
Philadelphia ADU Rental Restrictions
Some RestrictionsShed Rules
Philadelphia exempts a small shed from permits only when it is 120 sq. ft. or less, no taller than 15 ft. (one story), located in the rear yard, and accessory to a one- or two-family dwelling - per L&I Permit Guide PG_011 and the Zoning Code. A shed in a front or side yard, or larger than 120 sq. ft., requires a zoning permit, and a shed over 200 sq. ft. requires both a zoning and a building permit.
Sheds 120 sq ft or less in rear yard need no permit
Some RestrictionsPhiladelphia L&I Permit Guide PG_011 (FAQ: Shed), Permitting Requirements Table and Notes 1-5 (Sept. 2020)
The following table outlines permitting requirements for sheds that are accessory to one- or two-family dwellings: [Shed 120 ft2] In rear yard: Zoning Permit Not Required; In front / side yard: Zoning Permit Required; [> 120 ft2 and 130 ft2] Allowable per Zoning Code, Zoning Permit Required, Building Permit Not Required; [> 130 ft2 and 200 ft2] Not permitted per Zoning Code; [> 200 ft2] Zoning ...
Garage Conversions
Philadelphia does not have a standalone garage-conversion ordinance, but a detached garage is the prime candidate for an accessory dwelling unit under Zoning Code Section 14-604(11): an ADU may be located inside a detached accessory building such as a detached garage that already existed as of the Code's effective date, in the RSA-5 or CMX-1 districts, up to 800 sq. ft., owner-occupied. Converting a garage to any new use is a change of use requiring a use registration permit.
Detached garages can convert to ADUs by-right only
Some RestrictionsPhiladelphia L&I Accessory Uses FAQ (PZ_022_FAQ, June 2023), quoting Admin. Code A-301.1.5 and Zoning Code Sec. 14-604(1)(a)
Per A-301.1.5 a use registration permit is required for every new use commenced on any land or in any structure except for use as a single-family dwelling. Certain types of uses are considered accessory and are permitted in conjunction with the principle use without obtaining a separate permit. Per 14-604(1)(a), unless otherwise expressly stated in this Zoning Code, accessory uses and structure...
Carport Rules
Carports in Philadelphia are regulated as accessory structures under Phila. Code §14-604. They must be constructed in conjunction with or after the principal structure, comply with setback and height limits for the applicable zoning district, and obtain a zoning and building permit from L&I. In residential districts, they are typically permitted in side and rear yards.
Philadelphia Carport Construction Rules
Some RestrictionsTiny Homes
Philadelphia does not have specific tiny home regulations. Accessory dwelling units (ADUs) are permitted under §14-604(11) but must be within an existing principal building or existing detached accessory building. New freestanding ADU construction is not permitted by right. Tiny homes on wheels may be classified as RVs under §12-919.
Philadelphia Tiny Home & Small Dwelling Rules
Heavy RestrictionsLooking for Philadelphia County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Philadelphia city rules.
Accessory Structures in Philadelphia County →