# Knob and tube wiring removal in San Francisco

> Knob and tube wiring removal in San Francisco: dead runs verified, disconnected at both ends, pulled from attics and basements, and documented for BayREN.

URL: https://fogcitysfknobandtube.com/knob-and-tube-removal/

**Service**

Dead and abandoned runs verified, disconnected at both ends, taken out where reachable and recorded, so nobody mistakes them for live wiring later.

Last Updated: October 30, 2026

**Where**

San Francisco and the East Bay: Berkeley, Oakland, Alameda and Piedmont.

**Local rules**

- An electrical permit from DBI before new wiring goes in, then a pre-cover and a final inspection.San Francisco Electrical Code 89.127
- A separate permit for each dwelling unit, except in single-family (R-3) buildings.DBI fee schedule
- Only owner-occupants of a single-family home may pull their own electrical permit.SF Department of Building Inspection
- No insulation around concealed knob and tube without a licensed electrical contractor's certification.California Electrical Code 394.12
- Up to $2,000 toward active knob and tube for income-qualified PG&E customers in an EASE Home project.BayREN

[Fog City SF Knob and Tube](https://fogcitysfknobandtube.com/) manages knob and tube wiring removal in San Francisco and the East Bay: old runs that no longer serve the house are verified dead, disconnected at both ends, taken out where they can be reached, and recorded. Licensed and insured electrical contractors (California C-10) carry out the electrical work.

Removal and replacement are different jobs. Replacement, whether [partial](https://fogcitysfknobandtube.com/partial-knob-and-tube-replacement/) or a [whole-house rewire](https://fogcitysfknobandtube.com/whole-house-rewiring/), installs new circuits to take over from live knob and tube. Removal deals with the old wiring itself: the runs a past rewire left behind, the stubs a remodel cut off, the lengths in the attic that nobody is sure about. Some houses need both, in that order, but a house that was rewired years ago may need only removal and a record.

## Does knob and tube have to be removed?

Not by itself. San Francisco’s Electrical Code says existing wiring that was legal when installed and has been maintained need not be altered, and it requires unused conductors and cables to be either removed or suitably identified and terminated in an approved manner. So dead knob and tube can legally stay in a wall if it is disconnected and dealt with properly; the [California legality guide](https://fogcitysfknobandtube.com/guide/is-knob-and-tube-legal-in-california/) covers the wider rules. What brings removal up is usually something else: an attic about to be insulated, an insurer asking about the wiring, which an [electrical inspection for insurance](https://fogcitysfknobandtube.com/electrical-inspection-for-insurance/) answers in writing, or a buyer who wants to know that the porcelain knobs in the attic carry nothing.

The answer changes if a run is live. California Electrical Code 394.12 bars concealed knob and tube where insulation envelops the conductors, unless a licensed electrical contractor surveys and certifies it under the code’s California exception. A dead run that has been disconnected and removed takes that question off the table.

## What happens on the first visit

Every circuit is tested before any run is called dead, the same testing a [knob and tube inspection](https://fogcitysfknobandtube.com/knob-and-tube-inspection/) starts with. Each circuit is identified at the panel or fuse box and traced, and each knob and tube run seen in the attic, basement or garage is checked for voltage. The point is to sort runs into three groups: live, dead, and dead-looking but fed from somewhere else. That third group is the one that causes trouble.

The visit also looks at access. Attic height, a hatch versus a walk-up stair, existing insulation, stored belongings and the route down to the basement all affect how much can be pulled out and how long it takes. The written scope then lists which runs will be removed, which terminated in place and what, if anything, needs replacing first.

## Abandoned is not the same as disconnected

“Abandoned” knob and tube is wiring that no longer serves its original purpose, but the word hides several conditions. Some runs were properly disconnected at both ends during a rewire. Some were cut at the fuse box but left connected at the far end to outlets or splices. Some were abandoned by a remodel that stopped using a room’s old outlets yet left the run joined to a ceiling splice that still carries a later circuit. And some were never abandoned at all; they only look old.

Those differences matter because a run that is still connected at one end can be re-energized by a change elsewhere, and a run fed from a later circuit is live no matter what the fuse box says. The [active vs abandoned guide](https://fogcitysfknobandtube.com/guide/active-vs-abandoned-knob-and-tube/) explains how each condition arises. A San Francisco permit description from an insurer-driven job puts the goal plainly: the “insurance company advised owner to make it redundant and disconnect.”

## Isolating and verifying old circuits

Disconnection happens at both ends of each run. At the source end, the run is cut free of the panel, fuse block or the splice that fed it. At the load end, it is cut free of the outlets, lights and splices it served. Disconnecting only at the fuse box, as some earlier jobs did, leaves a length of wire still joined to devices and other conductors, waiting for someone to reconnect it by mistake.

After disconnection the run is checked again for voltage at every point that can be reached, and only then treated as dead. Each disconnected run is recorded with where it starts, where it ends and what was done with it. That record is what turns “we think it is dead” into a fact an insurer, buyer or BayREN can rely on, and it is the same discipline used on the retired runs of every [partial replacement](https://fogcitysfknobandtube.com/partial-knob-and-tube-replacement/).

## Removing it or leaving it in the wall

Once a run is verified dead, the choice is between taking it out and terminating it in place, and access decides. Runs in attics, basements, crawlspaces and garage ceilings are usually removed: the wire is pulled, and the knobs and tubes come out with it where they are loose or in the way. Of the 2,023 DBI electrical permits filed from January 2016 to October 2026 whose descriptions name knob and tube, 187 mention a basement, crawlspace or garage and 22 an attic, the spaces where most removal happens.

Runs inside closed plaster walls are a different case. Pulling them out would mean opening finished walls for wire that no longer does anything, so they are disconnected at both ends, identified and terminated in place, which is what the code allows for unused conductors. Physical removal is worth it where the wire would confuse the next person into the space or stand in the way of insulation; abandonment in place is worth it where removal would cost more in plaster than it gains in clarity. Where openings are needed for other work, [plaster-wall rewiring](https://fogcitysfknobandtube.com/plaster-wall-rewiring/) covers how they are kept small.

## Attic removal before insulation

Insulation is the strongest reason to pull knob and tube out of an attic. If the attic runs are live, they cannot be buried in insulation without the electrician’s survey and certification the code describes, or replacement first; the [attic insulation service](https://fogcitysfknobandtube.com/knob-and-tube-attic-insulation/) covers that route. If the runs are dead, removing them clears the attic and leaves nothing for an insulation installer or a future inspector to question.

Berkeley handles this with its own document. The city’s Form #146, the Knob-and-Tube Wiring Safety Report, has the electrician check one of three conditions, one of which is that the wiring is disconnected, not live or removed, and the form is posted in the attic before inspection, as the [Berkeley page](https://fogcitysfknobandtube.com/service-areas/berkeley/) describes. No equivalent DBI form was found for San Francisco, where what the insulation job needs is confirmed per address.

## The BayREN inactivity certification

BayREN’s EASE Home program offers up to $2,000 toward fixing active knob and tube, and its announcement of the offer also listed $300 toward a licensed electrician’s certification that knob and tube is inactive (the program page does not show that line, so confirm it with BayREN), for income-qualified PG&E customers in homes of four or fewer units built before 2010 whose EASE Home project includes a weatherization measure such as insulation or duct work. The program asks for the electrician’s invoice and the certification of inactivity. The contractors supply both, and Fog City SF Knob and Tube helps with the rebate paperwork; BayREN decides eligibility and the amount.

The limits matter in the East Bay. In San Francisco the income ceiling for a household of four is $232,050; in Alameda and Contra Costa counties it is $187,575. City of Alameda households buy power from Alameda Municipal Power rather than PG&E, so they fall outside EASE Home altogether. The [BayREN rebate guide](https://fogcitysfknobandtube.com/guide/knob-and-tube-rebate-bayren/) has the full conditions.

## What sets the cost

No published price exists for knob and tube removal, so a quote rests on the house. The drivers are access to the attic, basement and crawlspace; the number of runs; whether insulation already covers them; whether dead runs stay in the walls or come out; and whether any run tested live and has to be replaced before it can be removed. Insurer or BayREN documentation adds a written step. The [cost guide](https://fogcitysfknobandtube.com/guide/knob-and-tube-replacement-cost-san-francisco/) explains how removal fits alongside replacement in a full budget, and the [cost estimator](https://fogcitysfknobandtube.com/tools/knob-and-tube-cost-estimator/) gives a first number for the replacement side.

**Scope**

## What's included

- A test of every circuit, so each knob and tube run is confirmed live, dead, or fed from somewhere unexpected
- Disconnection of each retired run at both ends, at its source and at the outlets, lights or splices it fed
- A second check that each disconnected run carries no voltage at every point that can be reached
- Removal of dead wire, knobs and tubes from attics, basements, crawlspaces and garage ceilings where they can be reached
- Runs inside closed walls identified and terminated rather than torn out
- A written circuit record listing what was removed, what was terminated in place and what, if anything, is still live
- The electrician's invoice and inactivity certification BayREN asks for, with help on the rebate paperwork

**Choosing the scope**

## Leave it, disconnect it in place, or remove it

| Compare | Leave dead runs as found | Disconnect and terminate in place | Disconnect and remove |
| --- | --- | --- | --- |
| What happens to the old wire | Nothing | Cut off at both ends, identified and terminated | Cut off at both ends and taken out |
| Best fit | Runs already verified dead and documented | Runs inside closed plaster walls | Runs in attics, basements and garage ceilings |
| Openings | None | Usually none beyond boxes | Usually none in the living space |
| Risk of later confusion | High if undocumented | Low with a written record | Lowest; nothing left to mistake |
| Before attic insulation | Must still be shown dead | Runs shown dead and listed | Attic runs gone |
| Typical cost | None | No published range; depends on access | No published range; depends on access |

**Read next**

## Related resources

- [LearnHow can you tell active knob and tube wiring from abandoned runs?Live and dead knob and tube look identical. Insurers, the insulation rule, the BayREN rebate and the real hazard all turn on which one you have.](https://fogcitysfknobandtube.com/guide/active-vs-abandoned-knob-and-tube/)
- [Cost GuideIs there a knob and tube rebate in the Bay Area?One regional program pays toward knob and tube work, and only as part of an energy upgrade. Here is what it pays, who qualifies and what the paperwork needs.](https://fogcitysfknobandtube.com/guide/knob-and-tube-rebate-bayren/)
- [Decision GuideCan you insure a house with knob and tube in California?Getting a carrier to accept the house and getting anyone to pay for the work are separate questions. This guide takes them one at a time.](https://fogcitysfknobandtube.com/guide/knob-and-tube-insurance-california/)
- [LearnIs knob and tube wiring dangerous?The danger sits in what has happened to the wiring since it went in. Here is how each failure works, and which signs mean stop using a circuit today.](https://fogcitysfknobandtube.com/guide/is-knob-and-tube-wiring-dangerous/)

**How a job runs**

## From the first call to the Green Tag.

### First call

Tell us what started this: an insurer's letter, an inspection report, a remodel, an attic you want to insulate.

The age of the house, the number of units and any deadline shape the next step.

### Walk-through

Circuits are tested to separate live knob and tube from abandoned runs, and attic, basement and garage access is checked.

Plaster, trim and finishes are noted, and you get a written scope and price.

### The work

The permit is filed with DBI. New cable is fished along the planned routes and openings are kept small.

The pre-cover inspection happens before anything is closed.

### Patching, inspection and the Green Tag

Once the pre-cover inspection passes, the openings are patched. Plaster patching is included and shown as its own line in the quote.

After the final inspection and the Green Tag, old runs are removed or terminated and the panel directory is updated.

**On the job**

## What this work looks like

Empty white porcelain knobs still nailed to a basement joist after the old wire was taken out

A cut length of old cloth-covered wire, two porcelain knobs and wire cutters on a drop cloth

A small cardboard box of removed porcelain knobs and tubes on a plywood board in an attic

A cleared attic with no wiring left on the framing and a work light on the floor

**Questions**

## Knob and tube removal: questions

### How much does it cost to remove knob and tube wiring from an attic?

There is no published price for this work, locally or nationally. The cost turns on how easily the attic can be reached and moved through, how many runs there are, whether insulation already covers them, and whether any still feed live circuits below. A run that turns out to be live becomes a replacement, not a removal.

### How is old knob and tube confirmed dead before it comes out?

Every circuit is tested first, then each retired run is disconnected at both ends and checked again for voltage at every point that can be reached. Looking dead is not enough: a run cut at the fuse box can still be fed from a later circuit spliced into it downstream.

### What does BayREN's knob and tube inactivity certification need?

A licensed electrician's certification that the knob and tube is inactive, plus the electrician's invoice, for a household in BayREN's EASE Home program. BayREN's announcement listed a $300 rebate for it, for income-qualified PG&E customers in homes of four or fewer units built before 2010 doing a weatherization measure; the program page shows only the $2,000 remediation offer, so confirm the $300 with BayREN. BayREN decides eligibility.

### Will removing old knob and tube damage my plaster walls?

Usually not, because wire is pulled out only where it can be reached without opening finished walls: attics, basements, crawlspaces and garage ceilings. Runs inside closed plaster are disconnected at both ends and terminated in place, which San Francisco's Electrical Code allows for unused conductors. Opening a wall just to pull dead wire rarely makes sense.

### What paperwork comes with knob and tube removal?

A written circuit record listing each run removed, each run terminated in place and anything still live, plus a labeled panel directory. When the work is under a DBI electrical permit, the final inspection adds the city's record. Insurers, buyers, a future electrician and BayREN may each ask for some part of it.

**Related services**

## Other work on the same wiring

### Attic insulation and knob and tube

Attic knob and tube surveyed, replaced or disconnected so insulation can go in, with the paperwork BayREN's rebate asks for.

### Partial knob and tube replacement

The circuits still running on knob and tube replaced from the panel out, with a written record of exactly what remains.

### Knob and tube inspection

Every circuit traced and tested, live runs separated from dead ones, and findings that say plainly what was tested and what was only seen.