Portland homeowners rewiring a knob and tube home typically pay $8,000–$15,000 for a full house rewire, with the final cost driven by square footage, wall accessibility, and whether the existing electrical panel needs to be upgraded at the same time — which it usually does. Knob and tube wiring itself isn’t automatically a fire hazard if it’s in original condition and not overloaded, but the practical reality for most Portland homeowners is that insurance companies won’t cover it, lenders won’t close on it, and renovation work triggers mandatory upgrades under Portland BDS rules.
Electric Avenue PNW (CCB# 248553) has rewired homes throughout Portland’s older housing stock — Craftsman bungalows in Laurelhurst, postwar construction in Sellwood, early 20th century homes in Irvington and Alberta Arts. This guide covers what drives cost in Portland specifically, what the insurance and permit situation actually looks like, and what to expect from the rewiring process.
How Much Does Knob and Tube Rewiring Cost in Portland?
A full knob and tube rewire in Portland costs $8,000–$15,000 for a typical 1,000–1,800 sq ft home, with labor accounting for the majority of the cost. Wall accessibility is the single largest variable: open stud walls in an unfinished basement or attic add nothing; finished plaster walls in a 1920s Craftsman require fishing wire through walls, adding both time and drywall/plaster repair costs to the scope.
These ranges reflect typical Portland rewiring projects we’ve completed. Every home is different — square footage, wall construction, panel location, and permit complexity all affect the final number. The only way to get an accurate figure is a free site assessment.
| Scope | Typical Cost | Notes |
|---|---|---|
| Partial rewire — 1 room or specific circuits | $1,500–$4,000 | Common when a kitchen or bathroom renovation triggers a code upgrade |
| Single floor rewire | $4,000–$7,000 | Typical when only one level has active K&T |
| Full house rewire — 1,000–1,500 sq ft | $8,000–$12,000 | Most Portland Craftsman bungalows fall in this range |
| Full house rewire — 1,500–2,500 sq ft | $10,000–$15,000 | Larger homes, additional circuits, more complex routing |
| Full rewire + panel upgrade to 200A | $12,000–$18,000 | Most K&T homes have 60–100A panels that need upgrading at the same time |
What’s not included in these ranges: drywall or plaster repair after wire fishing, attic insulation removal and replacement (required to safely access K&T runs), smoke detector upgrades required by Oregon code, and AFCI/GFCI breaker upgrades on rewired circuits.
What Is Knob and Tube Wiring?
Knob and tube (K&T) is an early electrical wiring method used in American homes from approximately the 1880s through the 1940s. It gets its name from two components: ceramic knobs that anchor the wires to structural framing, and ceramic tubes that protect the wire where it passes through framing members. The system uses two conductors — a hot and a neutral — with no ground wire.
In its original state, K&T was a reasonable installation for the electrical loads of its era. The problems arise from what’s happened to it over the decades:
Insulation deterioration. The rubber insulation on K&T wiring becomes brittle and cracked with age — especially in attics subject to temperature swings. Cracked insulation exposes bare conductors.
Improper modifications. Previous owners or unlicensed contractors have spliced modern wiring into K&T circuits over the years, often without junction boxes or proper connections. These splices are a known failure point.
Over-fusing. K&T circuits are typically rated for 15 amps. If someone replaced the original 15A fuse with a 20A or 30A fuse at some point, the circuit can carry far more current than the wiring was designed for without tripping.
Insulation covering. K&T wiring requires air circulation to dissipate heat. When attic insulation was blown in over the decades — a common energy upgrade — it covered the wiring and eliminated that air circulation, causing heat to build in the conductors.
Is Knob and Tube Wiring Dangerous?
Knob and tube wiring in its original, undisturbed condition is not automatically a fire hazard — the National Electrical Code does not require its removal simply because it exists. The danger is in what typically happens to it over 80–100 years: deteriorated insulation, amateur modifications, over-fusing, and insulation burial are each individually a fire risk. In a Portland home built in 1925, it’s unlikely the K&T hasn’t been touched in 100 years.
The practical risk assessment: if your home has K&T, assume there have been modifications you can’t see. A licensed electrician can trace the circuits, identify splices, test for over-fusing, and assess whether the insulation is intact. That assessment — not a blanket assumption either way — is the correct starting point.
If you’re already experiencing warning signs in a home with K&T — burning smell, flickering lights, warm outlets or switches — treat those as an emergency. Read our guide on what counts as an electrical emergency in Portland for specifics on when to call immediately versus when to schedule.
Will Homeowners Insurance Cover a Portland Home with Knob and Tube Wiring?
Most major insurance carriers in Oregon will not write a new homeowners policy on a property with active knob and tube wiring, or will charge a significantly higher premium with reduced coverage. This is the most practical forcing function for K&T rewiring in Portland — not code, not safety concerns alone, but insurability.
The three scenarios Portland homeowners run into:
Buying a home with K&T. Lenders require proof of insurance before closing. If your insurer won’t cover the property without rewiring, you either rewire before closing or find a surplus lines carrier — expect significantly higher premiums and reduced coverage limits.
Existing policy renewal. Insurance carriers periodically require home inspections. If an inspection reveals active K&T, many carriers will give you 30–90 days to remediate or they’ll cancel the policy.
Filing a claim. If you have a fire in a home with K&T and your carrier can argue the K&T was a contributing factor, you may face a denied or reduced claim — even if you disclosed the K&T at policy inception. This varies by carrier but it’s a real exposure.
Bottom line: if you’re planning to sell, refinance, or simply maintain continuous coverage at standard rates, a K&T rewire is not optional in most Portland situations.
Portland-Specific Knob and Tube Considerations
Which Portland Neighborhoods Are Most Affected
Portland’s K&T homes are concentrated in neighborhoods developed before 1940. If your home was built during this period, there’s a meaningful chance K&T is present somewhere in the structure — even if previous owners rewired part of the home, original K&T often remains in attics, basements, and interior walls that weren’t opened.
High-concentration neighborhoods: Laurelhurst, Irvington, Alameda, Grant Park, Concordia, Alberta Arts, St. Johns, Kenton, Sellwood, Woodstock, Hawthorne, Buckman, Sunnyside, and parts of Northwest Portland. Older Lake Oswego and parts of West Linn also have significant pre-1940 housing stock.
Portland BDS Permit Requirements
Any rewiring work in Portland requires an electrical permit through Portland Bureau of Development Services (BDS). Oregon Revised Statute 479 mandates a licensed electrician and BDS permit for all new electrical circuit work. The permit process for a full rewire involves load calculations, a wiring plan submission, BDS plan review (5–14 business days), installation, and final inspection.
One thing that catches Portland homeowners off guard: the renovation trigger rule. When you pull a permit for a kitchen remodel, bathroom addition, or other renovation affecting the electrical system, BDS may require the affected circuits — and in some cases the entire system — to be brought up to current code. This is how a planned remodel turns into a full or partial rewire scope. A licensed electrician can tell you in advance what triggers apply to your specific project.
Panel Upgrades Are Usually Part of the Scope
Homes with K&T wiring almost always have original electrical panels — 60-amp or 100-amp fuse boxes that are undersized for modern loads. A full rewire adds circuits that a 60-amp panel simply can’t support. Most K&T rewire projects in Portland include a panel upgrade to 200 amps as part of the scope. Plan for it from the start rather than discovering it mid-project.
Note: NEC 230.85 now requires an outdoor emergency disconnect on any new panel installation. This adds approximately $1,000–$1,650 to panel replacement costs and is required by Portland BDS on all new panel work.
Jack’s Expert Take
“The K&T calls I get fall into two categories: someone who just found out their insurance is being canceled, and someone who just bought the house and is figuring out what they actually have. In both cases the first thing I tell them is: don’t panic, and don’t let anyone talk you into a full rewire before you’ve had a proper assessment. Sometimes half the house was already rewired at some point and only one floor or a few circuits still have K&T — that changes the scope and the cost significantly. The other thing I always flag: if the attic has insulation blown in over the K&T, that’s the highest-risk situation. The wiring can’t breathe, and that’s where we see the real problems. Get it assessed before you insulate, and definitely before you buy.”
— Jack, Master Electrician | Electric Avenue PNW | CCB# 248553
How Long Does a Knob and Tube Rewire Take in Portland?
| Phase | Timeline |
|---|---|
| Free site assessment | 1–2 hours on site |
| Permit application and BDS filing | 3–5 days |
| BDS plan review | 5–14 business days |
| Rewiring — partial or single floor | 1–3 days |
| Rewiring — full house | 3–7 days depending on size and wall accessibility |
| BDS final inspection | Within 1 week of completion |
Wall repair (drywall or plaster patching) is a separate scope completed after the electrician finishes the rough-in and passes inspection. Budget additional time and cost for that phase when planning your project timeline.
Frequently Asked Questions About Knob and Tube Rewiring in Portland
How much does it cost to rewire a house with knob and tube wiring in Portland?
A full house rewire for a typical Portland Craftsman bungalow (1,000–1,800 sq ft) costs $8,000–$15,000. Homes that also need a panel upgrade — which is most K&T homes — should budget $12,000–$18,000 for the combined scope. Partial rewires for one room or a few circuits run $1,500–$4,000. A free site assessment is the only way to get an accurate number for your specific home.
Is knob and tube wiring illegal in Portland?
No. Knob and tube wiring is not prohibited by the National Electrical Code or Portland city code simply because it exists. However, it cannot legally be extended or modified, and renovation work that triggers a BDS permit may require bringing affected circuits up to current code. The practical barriers — insurance and lender requirements — are what force most K&T rewiring projects in Portland, not a code mandate.
Will Portland homeowners insurance cover a house with knob and tube wiring?
Most standard carriers won’t write new policies on homes with active K&T, or will add exclusions and charge higher premiums. Existing policyholders may face cancellation notices after an inspection reveals active K&T. This is the most common reason Portland homeowners move forward with rewiring — not safety concerns alone, but the insurance situation making the home uninsurable or unfinanceable at standard terms.
Do I need a permit to rewire knob and tube in Portland?
Yes. Oregon Revised Statute 479 requires a licensed electrician and Portland BDS electrical permit for any new circuit work. The permit covers plan review, installation inspection, and creates the official record that satisfies insurance carriers and lenders. Unpermitted rewiring is a material defect under Oregon real estate disclosure law.
Can knob and tube wiring be repaired instead of fully replaced?
Individual circuits can be repaired or partially replaced rather than doing a full rewire — and in some cases that’s the right approach. A licensed electrician can assess which circuits are in acceptable condition and which need replacement. The no-ground limitation of K&T (meaning no three-prong outlets without GFCI protection) can’t be remediated short of full replacement, which is a factor for modern appliance use.
What is aluminum wiring and is it different from knob and tube?
Yes — these are two separate issues. Knob and tube (1880s–1940s) uses copper conductors. Aluminum branch circuit wiring was used in homes built roughly 1965–1973 as a cost-saving measure during a period of high copper prices. Aluminum expands and contracts more than copper, causing connections to loosen over time and generate heat. Both require a licensed electrician to assess and remediate, but the solutions are different — aluminum wiring remediation often involves CO/ALR-rated devices at connection points rather than a full rewire.
How do I know if my Portland home has knob and tube wiring?
The most reliable method is a visual inspection of your attic and basement — K&T is identifiable by the ceramic knobs anchoring wires to framing and ceramic tubes where wires pass through joists. Portland homes built before 1940 are the highest-probability candidates. If you can’t safely access those areas, a licensed electrician can trace your circuits and identify what you have during a site assessment. Verify any electrician you hire holds an active Oregon CCB license at the Oregon CCB license lookup.
Get a Free Knob and Tube Assessment in Portland
If your Portland home was built before 1940 and you’re dealing with insurance questions, a planned renovation, or concerns about what’s in your walls — start with a free site assessment. Electric Avenue PNW traces your circuits, identifies what actually needs replacing, and gives you a specific estimate before any work begins. No pressure, no upsell — just an honest assessment of what you have.
Call or text (503) 816-8821, or request a free assessment online. We serve all of Multnomah, Clackamas, and Washington counties — from Northeast Portland to Lake Oswego, Beaverton to Gresham. Licensed Master Electrician, CCB# 248553.