What is the Philadelphia zoning code?

Philadelphia's zoning code was substantially rewritten in 2012 after being largely unchanged for decades. The 2012 code adopts form-based principles and organizes residential zones by typical housing type in Philadelphia neighborhoods.

Residential zone families:

• RSA (Residential Single-family Attached) — rowhouses. RSA-1 largest lots through RSA-6 most compact.
• RSD (Residential Single-family Detached) — detached single-family. RSD-1, RSD-3.
• RTA (Residential Two-family Attached) — duplexes. Mostly RTA-1.
• RTD (Residential Two-family Detached) — detached duplex.
• RM (Residential Multi-family) — apartments, mixed-density.

Typical rowhouse neighborhoods:

• Fishtown, Northern Liberties, Old City — often RSA-5.
• Rittenhouse, Washington Square West — RSA-5 or RM-1.
• Society Hill — mostly historic overlay on top of RSA-5.
• Pointe Breeze, Fairmount, Francisville — RSA-5.

RSA-5 standards (most common rowhouse zone):

• Minimum lot area: 720 sqft.
• Minimum lot width: 16 feet.
• Minimum front setback: 0 feet (buildings typically built to front property line).
• Minimum rear setback: 9 feet.
• Side setbacks: 0 feet (party walls).
• Maximum height: 38 feet (3 stories typical).
• Maximum FAR: 0.8.

Philadelphia ADU rules (2022 revisions):

• ADUs permitted in RSA-1, RSA-2, RSA-3, RSA-4, RSD-1, RSD-3 zones.
• Maximum 800 sqft.
• Meet setback requirements.
• One additional parking space.
• Owner occupancy required (either primary or ADU).
• Short-term rental of ADU prohibited.

Historic district overlays:

• Old City National Register District.
• Society Hill — Philadelphia Historic Commission review.
• Rittenhouse Historic District.
• Many neighborhood-level historic districts.
• Historic review adds 3-6 months and can require specific materials, window styles, and design.

Zoning review process:

• Philadelphia Department of Licenses & Inspections handles building permits.
• Separate Zoning Permit required for many projects (issued by L&I).
• If zoning non-compliant, must go to Zoning Board of Adjustment (ZBA) for variance.
• ZBA is known as tough in Philadelphia — variance grant rates vary by neighborhood and type.

Typical Philadelphia permit timelines:

• Simple residential remodel (no zoning issue): 4-8 weeks.
• Addition with zoning compliance: 6-12 weeks.
• ZBA variance: add 3-6 months for hearing + decision.
• Historic Commission review: add 2-4 months.

Registered Community Organization (RCO) process:

• Philadelphia requires notification to RCOs (neighborhood groups) for certain zoning applications.
• RCO meetings can influence ZBA decisions.
• 45-day notice period typical.

Common Philadelphia remodel questions:

• "Can I add a deck?" — usually yes with setback compliance, but historic overlay may restrict.
• "Can I add a third floor?" — depends on existing building height vs. 38-foot limit and RCO/historic review.
• "Can I convert basement to apartment?" — depends on zoning (may require variance) and egress compliance.

AskBaily's Philadelphia contractor pool is familiar with Title 14, ZBA process, and historic commission review. See /philadelphia for deeper local context.