# Whole House Rewiring in Boston

> Whole house rewiring for older Boston-area homes: every circuit traced, new grounded cable fished through plaster, AFCI throughout, permits and inspections.

URL: https://deckerbostonknobandtube.com/whole-house-rewiring/

[Decker Boston Knob and Tube](https://deckerbostonknobandtube.com/) arranges whole house rewiring for older homes across Boston, Cambridge, Somerville and nearby cities, carried out by licensed and insured electrical contractors. A whole house rewire replaces every branch circuit in the house, not only the ones on porcelain knobs, with new grounded cable from the panel to each outlet, switch and light. It is the right scope when the old system runs through most rooms or has been patched by several generations of owners. When only a few original circuits remain, a [partial replacement](https://deckerbostonknobandtube.com/partial-knob-and-tube-replacement/) usually costs less and opens fewer walls.

## What happens on the first visit

The first visit finds out what the house actually has. A home inspection that says “knob and tube observed” confirms the wiring method exists, not how much of it is live, so the visit starts at the panel and works outward.

### Circuits first, then access

The electrician traces each circuit to the rooms it feeds and records what it is made of: knob and tube, cloth-sheathed cable, early armored cable or later cable, and where one was spliced into another. The [knob and tube inspection](https://deckerbostonknobandtube.com/knob-and-tube-inspection/) page describes that tracing in detail. Then the visit turns to routes: whether the attic can be walked, whether the basement ceiling is open, where closets stack between floors, and whether blown-in insulation already covers old runs.

### What you get back

You get a written scope. It lists each new circuit, each old run to be disconnected and left in place, the openings the routes need, whether the panel stays, and what patching is included. That document is also the fairest way to compare prices, because it shows exactly what each one covers; the [quote comparison guide](https://deckerbostonknobandtube.com/guide/comparing-knob-and-tube-rewiring-quotes/) lists what to check.

## When a whole house rewire is the right scope

A full rewire is decided by the condition and mix of the wiring, not the age of the house. Nearly half of Boston’s housing units were built before 1940, according to Census figures, but that is a reason to look, not proof of what any one house contains.

### Three eras of wiring in one house

Knob and tube ran separate hot and neutral conductors on porcelain through the framing, with no ground. It held up for decades partly because the wires sat in open air and shed heat. The risk usually comes from what was added later: cloth-sheathed cable from mid-century remodels, early armored cable, and splices joining all three, sometimes buried in a wall with no box. When a house has all of that, replacing one type at a time means returning to the same walls again and again. The [cloth wiring replacement](https://deckerbostonknobandtube.com/cloth-wiring-replacement/) page covers the mid-century cable on its own.

### Circuits sized for a different load

Original circuits were laid out for lights and a few outlets. Space heaters, window air conditioners and kitchen appliances now land on the same runs, and oversized fuses fitted when the originals kept blowing remove the protection that matched the wire. A rewire is when the circuit count is planned around the loads the house actually runs, and a load calculation decides whether the service can carry them. The [guide to how many amps knob and tube can handle](https://deckerbostonknobandtube.com/guide/knob-and-tube-max-amps/) explains why those old circuits overheat.

### When it isn’t needed

The Massachusetts code does not by itself force a full rewire. Rule 3 of 527 CMR 12.00 lets new work be added without bringing the rest of an installation up to code, so long as it doesn’t create or worsen a violation. Where earlier owners already rewired most rooms, the remaining knob and tube may feed a bedroom and a few ceiling lights. Tracing shows that, and the [partial vs full guide](https://deckerbostonknobandtube.com/guide/partial-vs-full-knob-and-tube-replacement/) weighs the two.

## Getting new cable through plaster, strapping and three floors

Most of a rewire is fished, not torn open. The Massachusetts text of the code allows cable to be fished between access points for concealed work in finished buildings where strapping it to the framing is impracticable, which is what makes a plaster-preserving rewire possible.

### Attic down, basement up

Where the attic is walkable, top-floor circuits run across the joists and drop into wall cavities. Where the basement ceiling is open, main-floor circuits come up from below. Closets that stack over each other and old chases carry cable between floors without crossing finished walls. Openings are still needed at outlet and switch locations and wherever a fire block or header stops the cable.

### Strapped ceilings and taller buildings

Where a ceiling was plastered over wood furring strips, the state code treats cable run diagonally behind strapping of about three-quarters of an inch as supported, provided it isn’t pulled taut. In a [three-decker](https://deckerbostonknobandtube.com/triple-decker-rewiring/), each floor is usually its own dwelling unit and is often rewired as its own stage. In buildings over three stories, cable circuits generally may not leave the floor or unit they start from, which changes the plan in the taller rowhouses covered on the [Back Bay, Beacon Hill and South End page](https://deckerbostonknobandtube.com/service-areas/back-bay-beacon-hill-south-end/).

### Openings, lead paint and who patches

In a house built before 1978, opening more than six square feet of painted surface per room turns the job into lead-safe renovation work under the state’s Department of Labor Standards rules, with a licensed lead-safe renovation contractor and containment. Small fishing holes can stay under that line, while a gut rewire usually can’t. The [plaster wall rewiring](https://deckerbostonknobandtube.com/plaster-wall-rewiring/) page covers how openings are cut and closed.

## What the Massachusetts code asks of the new system

Every whole house rewire permitted in Massachusetts after April 24, 2026 is inspected to 527 CMR 12.00, which adopts the 2026 National Electrical Code with the state’s amendments. A few of those rules shape the job more than the rest.

| Rule | What it means for a rewire |
| --- | --- |
| MA 210.12(B), arc-fault protection | Every 120 volt, 10, 15 and 20 amp branch circuit in a dwelling unit needs arc-fault protection, not only bedrooms and living rooms. That sets the breaker count and often the panel. |
| MA 210.8, ground-fault protection | Receptacles within 6 feet of a sink, or inside a cabinet supporting one, need ground-fault protection. |
| 334.80, cable in insulation | Where new cable runs through thermal insulation, its rating is taken at the lower 60°C value, which affects wire size on loaded circuits. |
| Rule 10, inspection before cover | Wiring can’t be concealed until the inspector of wires has seen it, within 72 hours of notice, weekends and holidays excluded. Plaster patching waits for that. |

### The Boston permit

In Boston, [Inspectional Services](https://www.boston.gov/permitting/permits/electrical-permit) requires a licensed contractor to apply for the electrical permit and do the work; a homeowner can’t pull it. ISD’s fee is a $20 application fee plus $1 per fixture, plug or outlet and $5 per meter when the service doesn’t change, or $0.25 per amp when it does. Work may not start until the permit is issued. Other cities have their own wire inspectors and fees, covered in the [Boston permit guide](https://deckerbostonknobandtube.com/guide/boston-electrical-permit-for-rewiring/).

Start with what's still live

Tracing the circuits tells you whether this is a full rewire, a partial job or something smaller.

Get an Estimate

(617) 405-3599

## Living in the house while it’s rewired

Most households stay put. The work moves area by area, so a given room loses power for part of a day rather than for the whole project, and each floor’s circuits are switched to the new panel as they are finished. Say up front which loads matter most, such as a home office, a medical device or the refrigerator, so those circuits are planned first.

Winter work needs one more check. Boston’s Logan Airport station averages about 92 days a year at or below freezing, according to NOAA, so any shutdown has to keep the boiler or furnace controls powered. The [living at home guide](https://deckerbostonknobandtube.com/guide/living-at-home-during-rewiring/) covers dust, furniture and the practical side.

## Insurance, Mass Save and paying for the work

A rewire usually starts because someone else asked about the wiring. What matters afterwards is the paperwork: the closed permit with the final inspection, the panel schedule and a written summary that no knob and tube remains in service.

### Insurers

No Massachusetts regulator sets a knob and tube rule for insurers. Carriers set their own terms, and the state’s FAIR Plan inspection reviews whether electrical systems are safely arranged. Homeowners report deadlines at purchase or renewal, so ask for the request in writing and check it against the scope before work starts. A completed rewire answers the question; no one can promise a carrier’s decision. The [Massachusetts insurance guide](https://deckerbostonknobandtube.com/guide/knob-and-tube-insurance-massachusetts/) explains what to ask.

### Mass Save

A Mass Save Home Energy Assessment that finds knob and tube stops wall and attic insulation until a licensed electrician certifies the work areas are free of active knob and tube. A whole house rewire clears that for the whole house at once. Moderate-income households in 1 to 4 unit homes can get Mass Save’s barrier incentive of up to $7,000, and the Mass Save HEAT Loan offers 0% financing for pre-weatherization barriers after an assessment. The [grants guide](https://deckerbostonknobandtube.com/guide/knob-and-tube-removal-grants-massachusetts/) covers eligibility and the [insulation barrier service](https://deckerbostonknobandtube.com/knob-and-tube-insulation-barrier/) covers the certification itself.

### What moves the price

A typical Boston-area budgeting range for a whole house rewire is $8,000 to $25,000 or more, and larger, plaster-heavy or service-upgrade jobs can run well past it. The biggest factors are how many circuits are live, the number of floors, attic and basement access, plaster versus drywall, and whether the panel changes; a panel or service upgrade alongside the job falls in a typical Massachusetts range of $3,000 to $6,500. Labor is part of it: electricians in the Boston metro earn a mean $40.08 an hour, about 17% above the $34.37 national mean, according to the Bureau of Labor Statistics. A wage is not a billing rate, which also carries insurance, licensing, vehicles and overhead. The [Boston cost guide](https://deckerbostonknobandtube.com/guide/knob-and-tube-replacement-cost-boston/) breaks the price into parts, and the [cost estimator](https://deckerbostonknobandtube.com/tools/knob-and-tube-cost-estimator/) gives a range without a phone call.

## What's included

- Tracing every circuit from the panel and recording which are knob and tube, cloth-sheathed cable, early armored cable or later wiring
- A written scope listing each new circuit, each old run to be disconnected and left in place, and each opening the routes need
- New grounded cable to every outlet, switch and light, with new boxes wherever the old ones can't hold modern devices
- Arc-fault protection on every 120 volt branch circuit in the dwelling, and ground-fault protection near sinks, as Massachusetts requires
- Dedicated circuits planned for the kitchen, bath and laundry, sized from the loads the house runs today
- The electrical permit filed by the licensed contractor, a rough-in inspection before walls close and a final inspection
- Old circuits disconnected at the panel and confirmed dead, with reachable attic and basement runs removed
- A labeled panel schedule and a written summary stating that no knob and tube remains in service
- A separate quote line for patching openings, so you know who closes them and to what finish

## Whole-house rewire, partial replacement or leave and monitor

|  | Whole-house rewire | Partial replacement | Leave and monitor |
| --- | --- | --- | --- |
| Fits a house where | Knob and tube, cloth cable and old splices run through most rooms | Earlier remodels replaced most circuits and a defined few remain | Tracing shows the old runs are dead, or one sound circuit feeds light loads |
| What changes | Every branch circuit is new, grounded and arc-fault protected | Only the circuits still on old wiring are replaced | Nothing is replaced; dead runs are confirmed and recorded |
| Openings and patching | Spread across every floor, planned once | Concentrated where the remaining circuits run | None, beyond any access needed to confirm |
| Panel | Usually needs more spaces, often a new panel | Often fits the existing panel | No change |
| Insurance, sale and Mass Save | One record that no knob and tube remains in service | A written boundary showing where old wiring still exists | A written statement of what is inactive; any live run keeps the questions open |
| Main risk | Highest upfront cost and the most access work | Mixed systems can hide splices the next owner finds | Conditions change if anyone extends, insulates over or overloads the circuit |

## Related resources

Decision Guide

What are the signs your house needs rewiring?

Old houses rarely announce bad wiring with one clear symptom. Sorting what you notice into urgent, worth planning for and not a symptom at all tells you what to do next.

Learn

Can you live in a house while rewiring?

Most households stay put through a knob and tube rewire. What makes that comfortable is planning the shutdowns, the dust and the heat before the first circuit goes dark.

Learn

How many amps can knob and tube handle?

Search for one number and you'll find several, none of which describes your house. The safe load on an old circuit comes from its wire, its surroundings and the fuse that protects it.

Cost Guide

How much does knob and tube replacement cost in Boston?

The range Boston-area owners budget with, the handful of things that push a house toward either end, and the public figures sitting inside every price.

Decision Guide

Should you replace part of your knob and tube or all of it?

Repair, partial replacement and a whole-house rewire answer different problems. The circuit map, the reason you're acting now and your plans for the walls decide which one fits.

## How a knob and tube job runs from first call to sign-off

1. First call Tell us what prompted the call, the town and type of building, how many units it has, and any deadline from an insurer, a sale or an insulation contractor. Photos, an inspection report or a Mass Save assessment help route the job to the right licensed electrician.
2. Assessment The electrician reviews the panel and the accessible attic and basement wiring, traces circuits, and notes which knob and tube is active, abandoned or mixed. You receive written findings and a scope, with access, patching and permit items listed separately.
3. The work The licensed contractor files the permit, then works area by area so the rest of the house keeps power. New cable is fished or run through open framing, the rough-in is inspected before walls close, and old circuits are disconnected and removed where reachable.
4. Completion Circuits are tested and labeled at the panel, the final inspection closes the permit, and you get the records: what was replaced, what was abandoned in place, and any knob and tube that remains. Those papers answer insurers, buyers and Mass Save.

## What this work looks like

Old fuse box and a new breaker panel with new cables on a plywood backboard in a Boston basement

New blue outlet box set into an opening in an old plaster wall above the baseboard, with a new cable and a drop cloth

New round metal ceiling box between framing members with a new cable leading to it

Finished painted plaster wall with a new outlet and light switch after rewiring

Find out whether your house needs a full rewire

Tracing the circuits answers it. Some houses that look like full rewires turn out to need less, and some that look partly updated need more.

Get an Estimate

(617) 405-3599

## Whole-House Rewiring questions

### How long does a whole house rewire take in an occupied home?

It depends on the number of floors, how many circuits are being replaced, and how open the attic and basement are. The inspections add their own waiting time: Massachusetts rules say new wiring can't be covered until the inspector of wires has seen it, within 72 hours of notice, weekends and holidays excluded. Ask for a written schedule that shows the working days for each floor and where each inspection falls.

### Does Massachusetts code require rewiring the whole house when knob and tube is found?

No. Rule 3 of 527 CMR 12.00 lets new work be added to an existing installation without bringing the rest of it up to the current code, and the state's interpretation committee has said a service can be replaced without replacing knob and tube circuits. A full rewire is chosen for the condition of the wiring, an insurer's request, a Mass Save barrier or the owner's plans, not because the code orders it.

### Does a whole house rewire also replace cloth wiring and old armored cable?

It should, and the scope should say so in writing. Many older Boston-area houses carry wiring from several decades: original knob and tube, cloth-sheathed cable from mid-century updates and early armored cable. A whole-house scope replaces every branch circuit regardless of type, so the finished summary can say the house has one modern system rather than listing which old types are left.

### Is it better to replace the panel before the rewire or at the same time?

Usually at the same time, as one planned job. Every new circuit needs a breaker space, and Massachusetts requires arc-fault protection on every 120 volt branch circuit in a dwelling, so an old fuse box or a full panel rarely has room. Doing both together means one permit sequence and one panel schedule. A service upgrade adds a utility work request with Eversource or National Grid.

### What does a whole house rewire cost in the Boston area?

A typical Boston-area budgeting range of $8,000 to $25,000 or more covers replacing the active circuits in a single-family house or one building. Larger houses, plaster-heavy jobs and jobs with a service upgrade can run well past it. Plaster patching is usually priced separately, and a panel or service upgrade alongside the job falls in a typical Massachusetts range of $3,000 to $6,500. A written scope turns the range into a price for your house.

## Related services

### Fuse Box and Panel Upgrades →

Fuse boxes and full panels replaced, and 60 or 100 amp services enlarged where the load calculation calls for it, planned together with the rewire.

### Plaster Wall Rewiring →

New circuits fished through plaster-and-lath houses with routes planned to keep openings few and small, and patching scoped in writing.

### Triple-Deckers and Multi-Family →

Knob and tube replaced across occupied apartments, shared stairs and basements in three-deckers, two-families, condos, brownstones and rowhouses.