If you live in a home built before the 1950s, you might still have knob and tube wiring hiding behind your walls. This outdated system can be a serious fire hazard and often fails modern electrical inspections. You’ve probably asked yourself how much to replace old knob and tube wiring — and if it’s really worth the investment. The short answer: costs range from $5,000 to $20,000 for a full replacement, but the price depends on your home’s size, accessibility, and local labor rates. In this guide, I’ll break down every cost factor, compare your replacement options, and help you make a smart decision without overspending.

Let’s walk through what you need to know before calling an electrician. Read also: Cost to Upgrade Electrical Panel to 200 Amps: Full Guide 2026 — because replacing old wiring often means your panel needs an upgrade too.

Factors That Affect How Much to Replace Old Knob and Tube Wiring

Several variables influence the final price. Understanding them helps you budget accurately and avoid surprises.

Size and Age of Your Home

Larger homes require more wire, more labor, and more time. A 1,200‑square‑foot bungalow may cost $5,000–$8,000, while a 3,000‑square‑foot Victorian could run $15,000–$25,000. The number of rooms, circuits, and outlets also matters.

Accessibility of the Wiring

Knob and tube is often hidden in walls, crawlspaces, or attics. If your home has open access (basement or attic with easy crawl space), labor costs drop. Plaster and lath walls require extra care and increase costs by 30–50% compared to drywall.

Local Labor Rates and Permits

Electrician rates range from $50 to $150 per hour depending on your region. Urban areas like New York or San Francisco cost more. Permits and inspections add $200–$1,000, but you should never skip them — improper work can be deadly.

Partial vs. Full Replacement

Some homeowners replace only exposed sections or upgrade certain circuits. This may cost $1,500–$5,000 but leaves hidden dangers. A full replacement ensures safety but costs more upfront.

Additional Upgrades Needed

Old knob and tube often connects to outdated fuse boxes or undersized panels. You’ll likely need a panel upgrade (typically $1,200–$2,500). Also consider adding ground fault circuit interrupters (GFCIs) and arc‑fault breakers (AFCIs). Read also: DIY Smart Home Installation Guide for Beginners Step by Step — once the wiring is safe, smart upgrades become easier.

Knob and Tube Replacement Cost Breakdown

Here is a realistic cost range for the most common replacement scenarios in 2026. Prices are in USD and include materials and professional labor.

Replacement Option	Average Cost Range	Time to Complete	Permits Required?	Safety Risk	Best For
Full rewiring by licensed electrician	$8,000 – $20,000	3–7 days	Yes	Low (when done properly)	Homeowners who want complete safety and insurance compliance
Partial rewiring (critical circuits only)	$1,500 – $5,000	1–2 days	Sometimes	Moderate (remaining wires still old)	Temporary fix or budget‑constrained homes
DIY replacement (with licensed helper)	$2,000 – $6,000 (materials + helper)	1–3 weeks	Yes (often required)	High (electrocution & fire risk)	Handy homeowners with electrical experience and permit knowledge
Specialized knob and tube removal company	$10,000 – $25,000	4–10 days	Yes	Low	Historic homes needing careful preservation of plaster
Combination with panel upgrade	$9,000 – $22,000	4–8 days	Yes	Low	Homes with outdated panels (most knob and tube homes)

Note that prices vary widely by region. Always get three quotes from licensed electricians before committing.

Best Options for Replacing Knob and Tube Wiring

Here are the most common approaches, ranked by safety, cost, and practicality. Each includes pros, cons, and who it suits best.

Option 1: Full Rewiring by a Licensed Electrician (Best Overall)

Overview: This is the gold standard. A professional removes all knob and tube wiring and installs modern Romex (NM‑B) cable with properly sized circuits, GFCIs, and AFCIs.

Features: Complete removal, new copper wiring, grounded outlets, smoke‑/CO‑alarm compatibility, and updated panel (if needed).

Pricing: $8,000 – $20,000 for an average home. Includes labor, materials, permit, and final inspection.

Advantages:

• Eliminates fire and shock risks entirely.
• Increases home value and insurance eligibility.
• Supports modern appliances and smart home devices.

Disadvantages:

• High upfront cost.
• Requires running new wiring through walls — may cause cosmetic damage.
• Disruption to daily life (power off for days).

Best For: Long‑term homeowners, families with children, and anyone planning to sell within 5 years.

User Experience: Homeowners consistently report peace of mind after full rewiring. Many note that insurance premiums drop, and it becomes easier to install modern fixtures. Common feedback: “I wish I had done it sooner.”

Expert Opinion: Licensed electricians universally recommend full replacement. The National Fire Protection Association (NFPA) states that knob and tube wiring is a leading cause of electrical fires in older homes. The cost is justified by the safety gain.

Option 2: Partial Rewiring (Best Budget Choice)

Overview: You replace only the circuits that power high‑draw appliances or rooms you use heavily — kitchen, laundry, bathroom, and HVAC.

Features: New wiring for selected rooms; old wiring left in less‑used areas like attics or closets.

Pricing: $1,500 – $5,000, depending on circuit count.

Advantages:

• Lower immediate cost.
• Faster completion (1–2 days).
• Targets the riskiest areas.

Disadvantages:

• Remaining knob and tube can still fail or cause fires.
• Insurance companies may still require full replacement.
• Complicates future renovations.

Best For: Rentals or temporary homes, or homeowners saving up for full replacement.

User Experience: Some owners use partial rewiring as a stopgap. Many later regret not doing it all at once when they discover hidden old wiring during a renovation.

Expert Opinion: Partial rewiring is better than nothing, but it’s not a permanent solution. Most electricians advise full replacement because the remaining wire degrades further with age.

Option 3: DIY with Licensed Helper (Best for the Handy)

Overview: You buy materials and run the new wires, then hire a licensed electrician to connect the panel and inspect everything.

Features: You save on labor while ensuring critical connections are code‑compliant.

Pricing: $2,000 – $6,000 (materials $1–$2 per foot, helper $500–$2,000).

Advantages:

• Significant labor savings (40–60%).
• You control the timeline.

Disadvantages:

• Electric shock hazard — knob and tube is often live.
• Permit may require a licensed electrician to pull it.
• Improper routing can cause future problems.

Best For: Experienced DIYers who understand basic electrical principles and have studied local codes.

User Experience: Many DIYers find it satisfying, but locals who skip permits often face fines or insurance claim denials. Common advice: “Only do this if you’ve worked with wiring before.”

Expert Opinion: Even experienced electricians recommend against DIY for knob and tube replacement because of hidden dangers like brittle insulation and unknown junction boxes. It’s safer to hire a pro.

Option 4: Specialized Historical / Preservation Company (Best Premium Choice)

Overview: Some companies focus on restoring historic homes and use techniques to minimize damage to plaster walls and original features.

Features: Careful removal, chase routing, wall patching, and sometimes reuse of original knob and tube conduits for less visible areas.

Pricing: $10,000 – $25,000.

Advantages:

• Preserves architectural details.
• Often includes wall repair and repainting.
• Peace of mind with specialists.

Disadvantages:

• Most expensive option.
• Limited availability (not in all regions).
• Slower (up to 10 days).

Best For: Historic home owners, those with decorative plaster, or properties listed on heritage registers.

User Experience: Owners of Victorian and Craftsman homes appreciate that specialists avoid ruining original walls. However, some complain about premium pricing.

Expert Opinion: If your home has historic value, the extra cost is worthwhile. General electricians may cut corners that damage irreplaceable finishes.

Option 5: Combined Rewiring + Panel Upgrade (Fastest Comprehensive Solution)

Overview: Electricians bundle old wiring removal with a panel upgrade to 200 amps (or 100 amps if code allows).

Features: New breaker panel, all new circuits, ground rods, and whole‑house surge protection.

Pricing: $9,000 – $22,000.

Advantages:

• One stop — less coordination.
• Ensures panel capacity for modern appliances.
• Often cheaper than two separate jobs.

Disadvantages:

• Higher upfront cost than standalone rewiring.
• More invasive (panel location may need moving).

Best For: Homes with original 30‑ to 60‑amp fuse boxes – most knob and tube homes fall into this category.

User Experience: Homeowners appreciate that after a combined project, their electrical system meets current code. Many note that their home resale value jumps by more than the project cost.

Expert Opinion: This is the most efficient route. If your panel is old, you need a new one anyway — doing it together saves time and money. Read also: Best Smart Smoke Detector and Carbon Monoxide Alarm Combo for 2026 — once your wiring is safe, upgrade to smart detectors for added peace of mind.

What to Look for When Choosing a Replacement Method

Making the right choice involves more than just price. Consider these factors.

Important Features of a Good Rewiring Job

• Code Compliance: All work must meet the latest National Electrical Code (NEC) or your local equivalent.
• Proper Grounding: Knob and tube systems lack ground wires. New wiring must include a grounding conductor for every outlet.
• Arc‑Fault Protection: AFCI breakers on all living area circuits are now mandatory in most jurisdictions.
• Minimal Wall Damage: Pro electricians use techniques like fishing wires to avoid cutting large holes.
• Permit and Inspection: Never skip this — it protects you and proves the work is safe to insurers.

Pricing Factors to Watch

• Material Cost: Copper wire prices fluctuate. In 2026, expect $0.80–$1.50 per foot for 14‑gauge Romex.
• Number of Outlets and Switches: Each adds $50–$150 to labor.
• Drywall Repair: If the electrician doesn’t patch holes, you’ll need a handyman — $200–$800 extra.
• Light Fixtures: Removing and reinstalling old chandeliers or sconces can cost $100–$300 per fixture.

Hidden Costs You Should Know About

• Asbestos in Old Insulation: If your knob and wire is wrapped in cloth‑covered tar, asbestos may be present. Testing costs $300–$600; abatement can add $1,000–$3,000.
• Unexpected Splices: Electricians often find hidden junction boxes in walls that need to be exposed and properly connected.
• Moving Services: During a full rewiring, you may need to empty rooms and store furniture — factor in time and potential storage costs.
• Insurance Deductible: If you claim fire damage, your deductible may be $1,000–$5,000. Prevention is cheaper.

Tips for Choosing Wisely

• Get at least three written estimates from licensed electricians with knob and tube experience.
• Ask about wall repair: some electricians include basic patching, others don’t.
• Check reviews on Angi (formerly Angie’s List) and the Better Business Bureau.
• Verify insurance — the electrician should have liability and workers’ compensation.
• Plan the timing: rewiring is best done before moving into a home or during renovations when walls are open anyway.

Read also: Retrofit Smart Light Switch No Neutral Wire Required (2026): The Ultimate Guide to Upgrading Older Homes Without Rewiring — if you’re not ready for full rewiring, you can still add smart switches without a neutral wire.

Frequently Asked Questions

1. Is it safe to stay in the house during rewiring?
   Generally yes, but power will be off for most of the job. Electricians usually work circuit by circuit, so you may have partial power in the evening. If you have small children or medical equipment, consider staying elsewhere 2–3 nights.
2. Can I replace knob and tube wiring myself?
   Technically possible, but not recommended. Most building codes require a licensed electrician to pull permits and handle final connections. DIY mistakes can cause fires, and insurance may deny claims. Save money by doing demolition or wall repair work, not the wiring itself.
3. Does home insurance cover knob and tube wiring?
   Many insurers won’t cover homes with existing knob and tube wiring. Others charge higher premiums. After replacement, most insurers offer standard rates. Always notify your agent after rewiring to update your policy.
4. How long does a full rewiring take?
   For a standard 1,500‑sq‑ft home, expect 3 to 5 days. Larger or complicated homes may take up to two weeks. Delays often occur when unexpected issues like asbestos or inaccessible runs are found.
5. Will replacing knob and tube increase home value?
   Yes. Buyers often demand that knob and tube be replaced before purchasing. A full rewiring can increase resale value by 5–10% and help your home sell faster. Appraisers consider it a major safety upgrade.
6. What is the average cost per square foot to replace knob and tube wiring?
   Nationally, prices range from $4 to $12 per square foot for full replacement. That includes materials and labor. Use the lower end for simple bungalows and the higher end for historic homes with plaster walls.
7. Can I install smart home devices with knob and tube wiring?
   Some smart switches, plug‑in devices, and sensors work on ungrounded circuits, but many require a neutral wire. Smart home installations on knob and tube increase fire risk because old wiring can’t handle the added load. It’s safer to complete rewiring first. Read also: Best Energy Monitor Smart Plug for Home Appliances: Real Cost Savings in 2026 — once rewired, you can safely monitor energy usage.
8. What happens if I don’t replace knob and tube wiring?
   Risks include electrical fires, shock, and increased insurance costs. Many home sales fall through because buyers and lenders require replacement. Delaying may also lead to emergency situations costing more than planned replacement.

Final Recommendations

Best Overall: Full rewiring by a licensed electrician (Option 1). It provides the highest safety, increases property value, and complies with insurance requirements. You get modern grounding and arc‑fault protection.

Best Value: Combined rewiring + panel upgrade (Option 5). Bundling saves time and money compared to doing them separately. For most knob and tube homes, a panel upgrade is inevitable.

Best Premium Choice: Specialized historic preservation company (Option 4). If your home has unique plaster, crown molding, or historical designation, the extra cost is justified to preserve its character.

Best for Beginners / Homeowners on a Tight Budget: Partial rewiring (Option 2). It’s not a permanent fix, but it can make your home safer for less than $5,000. Use it as a stepping stone while you save for a full replacement.

Best for Advanced Users: DIY with licensed helper (Option 3). Only attempt if you have prior electrical experience and can safely handle live wiring. Even then, get professional guidance on code requirements.

Now you understand how much to replace old knob and tube wiring and the best approach for your situation. A full replacement is the most secure investment in your home’s safety and value.