The two permits every install needs
L&I's mechanical permit page says a licensed contractor must do the work, and that a one-or-two-family application is submitted with the HVAC Equipment Design Form. New installations in one-or-two-family homes can qualify for an EZ permit, which needs no plans. The electrical side must be done by a licensed electrical contractor, and the owner or owner's agent has to hire a licensed electrical inspection agency for the inspections.
If the job also counts as an exterior alteration, L&I says the Building Permit has to be issued before the Mechanical Permit. Its Building Permit page lists changes to "the interior or exterior of an existing structure" among the triggers, so ask L&I whether your wall brackets and penetrations fall under that or are covered by the trade permits. Our guide to furnace and central air permits in Philadelphia covers the same mechanical permit for whole-house systems.
The front wall: right-of-way comes first
This is the rule that surprises people. The Streets Department's Right-of-Way Improvement Standard lists "Air Conditioners" and "Air Conditioner Compressors" among encroachments that §11-600 of the Philadelphia Code doesn't allow over the legal right-of-way. No City department can permit them there without an ordinance of City Council.
Many rowhome fronts sit right at the property line, so a condenser bracketed to the front wall may hang over the sidewalk right-of-way. Mounting it high above the sidewalk doesn't change that. Ask the installer how far the unit and its line cover stick out, and where your legal property line is. L&I's mechanical page notes that work encroaching on the right-of-way needs Department of Streets approval, and L&I says to get required pre-approvals before you apply.
Zoning: exempt only in the right spot
L&I's Zoning Permit page says air conditioners don't need a Zoning Permit as long as they serve the property and aren't within a required setback from the property line. Look up your zoning district on the City's Atlas map, and if the unit might sit in a setback, ask L&I before it's mounted. Our guide to when a project needs zoning as well as a building permit explains how the two reviews fit together.
Historic designation covers more than the condenser
Use the City's historic property search with your official Office of Property Assessment address, which can differ from your mailing address. For recent designations, the City says to contact Historical Commission staff. The Philadelphia Register isn't the National Register, so an old house isn't automatically on it, and a listed one may not look special.
For a listed property, the Historical Commission's review covers "mechanical equipment and associated vents, pipes, conduits, and wires," so the refrigerant line cover and wiring on the facade count too. That review is free. Ask staff early whether a rear wall or roof location would be acceptable. Our historic designation guide walks through the lookup.
A few Center City blocks also get a facade review
The City Planning Commission reviews facades along designated parts of Broad, Market, Chestnut and Walnut streets. L&I will tell you at the building-permit stage if your project needs one (facade review page). Most rowhome blocks aren't affected.
What to get from the installer before you sign
- A marked-up photo of the wall showing the condenser, brackets, wall penetrations, line cover, wiring route and where the condensate drains.
- How far the unit projects from the wall, and whether that crosses the property line.
- Which permits they'll pull, and whether the mounting needs a separate Building Permit.
- Who books the mechanical inspections and which electrical inspection agency will be used.
Leave wall drilling and electrical work to the contractors. If the brick or the bracket design looks questionable, that's a question for the installer or a structural engineer.
Timing
Applications can go in through eCLIPSE or at L&I's Permit and License Center. In person, L&I says applications without plans are reviewed while you wait, and ones with plans within 20 business days (5 business days with paid accelerated review). Streets or Historical Commission approval comes before that. Our guide to tracking a Philadelphia permit shows how to follow it, and L&I issues approval documents only after the required inspections pass.