Knob-and-tube wiring replacement cost in Seattle (2026):
rewiring prices, extra costs and the City permit
HOW MUCH DOES IT COST TO REPLACE KNOB-AND-TUBE WIRING?
Angi puts knob-and-tube replacement at $12,000 to $36,600 for most homes, with a national average of $24,300, or $10 to $20 per square foot; a 1,600 sq ft home runs $16,000 to $32,000. Angi's Seattle rewiring figures are lower, $2 to $4 per square foot, but that page covers rewiring generally, not knob-and-tube. In Seattle, rewiring needs an SDCI electrical permit.
Knob-and-tube replacement cost
| Source | Reported cost |
|---|---|
| Angi, knob-and-tube replacement: most homes | $12,000–$36,600 |
| Angi, knob-and-tube replacement: average | $24,300 |
| Angi, knob-and-tube replacement: per sq ft | $10–$20 |
| Angi, rewiring a house in Seattle: typical | $836–$3,090 (average $1,957) |
| Angi, rewiring a house in Seattle: per sq ft | $2–$4 |
Angi says knob-and-tube wiring was installed from the 1880s to the 1940s. It describes replacing it as an outdated-component job that can be worth the cost and can help a home sell.
Cost by home size
| Home size | Knob-and-tube replacement (Angi) | Seattle rewiring (Angi) |
|---|---|---|
| 1,000 sq ft | $10,000–$20,000 | $2,000–$4,000 |
| 1,600 sq ft | $16,000–$32,000 | — |
| 2,000 sq ft | $20,000–$40,000 | — |
| 3,000 sq ft | $30,000–$60,000 | $6,000–$12,000 |
Extra costs
| Item | Reported cost |
|---|---|
| Drywall or plaster repair | $300–$900 |
| Electrical panel upgrade | $600–$4,000 |
| Inspection | $100–$150 each |
| Cleanup and disposal | $300–$500 |
The Seattle electrical permit
- Permit needed. SDCI issues electrical permits in Seattle and requires one whenever wiring is installed or altered.
- Inspections. SDCI inspects in stages: cover, service and final.
- Owner-occupants may do electrical work on their own home under an SDCI permit.
- Service upgrades may also involve Seattle City Light.
- Older homes: opening walls for rewiring may disturb old paint or materials that contain asbestos; check before work starts. See lead paint rules and asbestos testing.
Frequently asked questions
How much does it cost to replace knob-and-tube wiring?
Angi puts knob-and-tube replacement at $12,000 to $36,600 for most homes, with an average of $24,300, or $10 to $20 per square foot. Angi's Seattle rewiring page lists a lower $2 to $4 per square foot for rewiring in general.
How much does it cost to rewire a 1,600 sq ft house?
Angi's knob-and-tube guide lists $16,000 to $32,000 for 1,600 sq ft. Wall repair, a panel upgrade and sales tax are extra.
Do I need a permit to rewire a house in Seattle?
Yes. SDCI requires an electrical permit whenever wiring is installed or altered, with cover, service and final inspections.
Can I replace knob-and-tube wiring myself in Seattle?
SDCI allows owner-occupants to do electrical work on their own home with a permit and inspections. Otherwise, hire a licensed electrical contractor.
When was knob-and-tube wiring used?
Angi says it was installed from the 1880s to the 1940s.
About these prices. The ranges are published estimates from the sources below, as of the dates shown. Material costs, labor rates, tariffs and inflation can change prices after those dates, and your home may differ. Use them to plan a budget, then get written quotes from licensed contractors.
Sources
- Angi — Knob-and-tube replacement cost
- Angi — Cost to rewire a house in Seattle, WA
- Seattle Department of Construction and Inspections — Electrical permit
- Washington Department of Revenue — Custom construction
Angi accessed November 10, 2026; SDCI electrical permit page checked October 12, 2026.
This guide summarizes published cost estimates and City of Seattle rules. Electrical work is dangerous; hire a licensed electrical contractor unless you're qualified. See our disclosure and disclaimer.