Replacing knob and tube in Philadelphia needs an electrical permit from the Department of Licenses and Inspections (L&I), filed in eCLIPSE and carried out by a licensed electrical contractor. A one- or two-family house usually qualifies for an EZ permit without plans; larger buildings follow a different path. A licensed third-party inspection agency, not an L&I inspector, inspects the work.
Philly Knob & Tube arranges knob and tube replacement for Philadelphia houses and small apartment buildings, with the electrical work and the permit carried by licensed, insured electrical contractors. This page walks through the permit itself, step by step, so you can read a proposal and know whether the paperwork it describes matches what the City actually asks for.
When Philadelphia requires an electrical permit
L&I requires an electrical permit for the installation, alteration, renewal, replacement and repair of electrical systems. That covers almost everything a knob and tube job involves: new branch circuits, new boxes where the old ones cannot hold modern devices, new runs to the panel, and the disconnection of the old conductors.
The City publishes a narrow list of work that may go without a permit. It is limited to replacing lamps, breakers, fuses, switches, receptacles and lighting fixtures to existing conditions, and taping bare joints. The words “to existing conditions” are the key. Swapping a worn receptacle on a knob and tube circuit for an identical one leaves the circuit as it was. Running new cable from the panel to that receptacle changes the circuit, so it falls under the permit.
Two related situations come up often:
- Partial replacement. Replacing three circuits and leaving the rest is still an alteration, so it still needs a permit. The scope on the application is smaller, and so is the fee. The partial versus full replacement guide covers how that boundary is chosen.
- Disconnecting old runs. Making a knob and tube circuit dead at both ends is part of the replacement, and the inspection agency will want to see that replaced conductors no longer connect to anything live. The active versus abandoned guide explains why “cut at the panel” is not the same as abandoned.
Existing knob and tube is not, by itself, an open permit problem. Philadelphia enforces the 2020 National Electrical Code for new work; old wiring installed legally under earlier rules is an existing condition. The blog post on Philadelphia’s code transition explains why that distinction matters to buyers and insurers.
Who applies, and who must do the work
All electrical permit applications go through eCLIPSE, L&I’s online permitting system. The applicant is either the property owner or an authorized agent. L&I lists the agents who may apply: a licensed electrical contractor, a Pennsylvania design professional, an attorney or a licensed expediter.
Separately from who files, L&I is explicit about who works: all electrical work must be performed by a licensed electrical contractor. The contractor’s license has to be active, the contractor has to be current on City taxes, and proof of insurance has to be on file with L&I. That is the reason a homeowner in Philadelphia cannot rewire their own house under a homeowner permit, as some other places allow.
On most residential rewiring jobs the electrical contractor files the application as the owner’s agent. That arrangement puts the permit, the inspections and any corrections in the hands of the party who controls the work. If a proposal asks you to file the permit yourself, ask why, and read the hiring guide on what that request can signal.
If the electrical contractor changes partway through, the permit record has to be updated to name the new one before that contractor continues; L&I has a process for changing the contractor on an open permit. A half-finished rewire handed from one contractor to another is also a moment to ask for a written circuit list of what was completed, because the second contractor will be signing for work they did not install.
Timing matters too. The permit should be issued, or a Rough-in Permit approved, before cable goes into the walls. Work that starts first and gets permitted afterward can leave the inspection agency unable to see rough-in that has already been covered, and the fix for that is opening the plaster again.
Property type: EZ permit or plan review
How the application is reviewed depends on the building, not on how much wire is involved.
One- and two-family dwellings. L&I offers an EZ electrical permit, issued without plans, for alterations to a one- or two-family dwelling where the connected load is under 200 amps and the equipment is rated 600 volts or less. A typical Philadelphia rowhouse or twin being rewired circuit by circuit fits that description, and eCLIPSE routes one- and two-family permits to its Residential side.
Three- and four-unit buildings. eCLIPSE sends everything other than a one- or two-family dwelling to its Commercial side, even when the building is plainly residential, such as a converted rowhouse with three apartments. Whether plans are needed depends on the project and the building, so a contractor should not promise an EZ permit for a three- or four-unit property before looking at it. Plans are always required when a building other than a one- or two-family dwelling is undergoing a change in occupancy classification. The multi-unit replacement page covers the extra coordination that comes with residents and shared systems.
Service work changes the picture. If the rewiring plan includes a service upgrade or a new panel with a larger service, the connected load and the utility side both come into play. A separate service and meter application to PECO may be required. A panel or service change does not replace branch wiring, which the panel upgrade comparison explains.
How the electrical permit relates to a Building Permit
L&I states that a separate Building Permit is required for interior and exterior renovations, and that most electrical work requires one. It also allows for the case where the project scope does not trigger a Building Permit; that is noted on the electrical application.
For knob and tube replacement, the question is usually whether the wall and ceiling openings, patching and any reframing are part of a broader renovation. A rewire done through small access openings in a house that is otherwise untouched is a different scope from a kitchen and bath gut where the rewiring rides along. The electrical contractor determines whether the scope triggers a Building Permit and records that on the application. If you are planning a renovation at the same time, tell the contractor early, because two permits filed and inspected in the wrong order can hold up the walls being closed. The renovation replacement page covers that sequencing.
On a property on the Philadelphia Register of Historic Places, exterior changes such as a new meter location or surface conduit on a facade can bring in the Philadelphia Historical Commission. The guide to historic Philadelphia homes explains what the Commission does and does not review.
Rough-in permits and inspections before walls close
Philadelphia does not send its own inspector to most electrical jobs. The owner, or the owner’s agent, hires a licensed electrical inspection agency, and that agency performs all the inspections on the permit. Many homeowners are surprised by this, because it means the inspection agency is a separate party with its own fee, and someone has to schedule it.
Two inspection points matter for rewiring:
- Rough-in. Applicable rough-in work has to be inspected before it is covered. In a plaster house, that means new cable fished through cavities, boxes set and runs stapled in the basement or attic are inspected before patching closes the openings. If a wall is patched before rough-in passes, it may have to be reopened.
- Final. After devices are installed, the panel is terminated and the circuits are energized and labeled, the agency inspects the finished installation. The final inspection guide covers what happens at that visit and what records come out of it.
L&I also offers an optional Rough-in Permit. It lets the contractor install cable before the full permit is issued. The approval lasts 60 days, and nothing installed under it may be concealed until it has been inspected. On a tight schedule, for example a house that has to be ready before a closing or before an insurer’s deadline, a Rough-in Permit can let work start while the main application is processed.
Ask any contractor you are considering which inspection agency they use, who pays it and how rough-in timing fits around the patching. The rewiring process guide shows where those inspections fall in the overall sequence.
Permit fee components, with a worked example
L&I calculates the electrical permit fee from the estimated cost of the electrical construction, not the whole project. The current components are:
| Component | Amount | Notes |
|---|---|---|
| Permit fee | $25 for each $1,000, or fraction, of estimated electrical cost | Minimum $63, maximum $18,975 |
| Filing fee | $100 | Nonrefundable, counted toward the final permit fee |
| City surcharge | $3 per permit | Added to the permit |
| State surcharge | $4.50 per permit | Added to the permit |
| Record retention | $4 per plan | Applies where plans are submitted |
| Rough-in Permit | $150 | Optional |
Worked example. Suppose the electrical portion of a rewiring proposal is $15,000. The permit fee is 15 times $25, which is $375. The $100 filing fee paid at application is credited toward that $375, so it is not added on top. The surcharges add $7.50. An EZ permit for a one- or two-family house has no plans, so the record retention charge would not normally apply. Adding a Rough-in Permit would bring another $150. This is an illustration of the arithmetic, not a fee quote for any particular house.
The “fraction” rule matters slightly: a scope of $15,200 counts as 16 units, because the extra $200 is a fraction of a thousand. The minimum means a very small job still pays $63.
Two costs sit outside L&I’s fee. The inspection agency bills separately, and Philadelphia does not publish a set price for it. Plaster repair, painting and any other trades are not electrical construction cost, so they do not raise the electrical permit fee, though they may fall under a Building Permit. The Philadelphia cost guide puts the permit in context against a whole-home budget, and the quote comparison guide shows how to see whether a proposal includes these fees or leaves them to you.
What to keep at completion
When the final inspection passes, the paperwork is what proves the work was done under permit. Insurers, buyers’ inspectors and future electricians will all ask some version of the same question, and a folder answers it faster than anyone’s memory. Keep:
- The permit number and the permit record from eCLIPSE, showing the licensed electrical contractor named on it.
- The inspection agency’s reports for rough-in and final, with dates and the agency’s name.
- A circuit list that says which circuits were replaced, which knob and tube runs were disconnected at both ends, and whether any knob and tube was left in service on purpose.
- The final invoice describing the electrical scope, separate from patching and painting.
- Any Building Permit or Historical Commission approval that went with the job.
If your insurer has asked for proof, find out in writing what form it wants. Some ask for an electrician’s letter, some for the permit record, some for both. The insurance guide and the buyer’s guide cover what those readers look for.
Before you sign anything
A good proposal for a Philadelphia rewire names who files the permit, which review path the building is on, which inspection agency will inspect and who pays it, whether a Building Permit is part of the scope and how rough-in inspection fits around patching. If any of those are missing, ask before you sign, not after the walls are open. When you are ready to talk through a specific house, start with the whole-home rewiring service or send the details through the contact page.
