Active knob and tube, replaced and signed off by the city.
A San Francisco brief for owners, buyers and agents dealing with knob and tube. Insurers want it gone. The right scope replaces exactly what is active, keeps what is already modern, and ends with a permit the carrier can see.
A three-level hillside home in San Francisco had active knob and tube wiring and ungrounded outlets. GBS inspected every level before pricing. The two lower levels had already been updated with modern grounded circuits, so they stayed out of scope. The original knob and tube was concentrated on the upper street level, including ungrounded outlets in a kitchen that looked updated but was not. The main panel was modern and adequate, so it stayed too. GBS replaced only the wiring that needed to go, and the job was permitted and signed off by the city.
Three-level hillside home, San Francisco
Why it matters
What we found and what we did
- Visual inspection of all three levels and the crawl space
- Lower two levels already modern and grounded: left alone
- Upper street level: mix of original knob and tube and newer work, set as the primary scope
- Main panel modern and serviceable: no replacement needed
- Active knob and tube de-energized, disconnected and removed where accessible, and replaced with new grounded cable
- Concealed wiring that cannot be reached without major demolition permanently disconnected at both ends and abandoned in place where the city allows
- Attic used as the wiring pathway where possible to limit wall openings
- AFCI and GFCI protection where code requires
- All new circuits tested, energized and labeled in the panel directory
How the payments followed the permit
- Deposit: $1,000
- Mobilization, materials and permit: $12,000
- Rough-in inspection signed off by the city: $11,000
- Final city sign-off on the permit: $10,650
How we delivered it
Figures reflect a specific completed GBS project. Price and scope on any other property depend on what the inspection finds.
Knob and tube in the way?
Whether it is an insurance notice, an escrow deadline or a home you just bought, send us what you know and we will scope exactly what needs to be replaced.
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