# Fuse Box to Breaker Panel Upgrades in Boston > Fuse box to breaker panel upgrades for Boston-area homes with knob and tube: load calculations, arc-fault space, service upgrades and utility coordination. URL: https://deckerbostonknobandtube.com/electrical-panel-upgrade/ [Decker Boston Knob and Tube](https://deckerbostonknobandtube.com/) arranges fuse box to breaker panel upgrades and service upgrades for older homes across Boston, Cambridge, Somerville and nearby cities, done by licensed and insured electricians as part of knob and tube work. The panel usually comes up because a rewire needs it: every new circuit needs an arc-fault breaker and a space to put it in. A new panel does not remove knob and tube, though. It changes the equipment protecting the circuits and leaves the wire in the walls as it was, which is why the panel is treated here as one decision inside a [whole house rewire](https://deckerbostonknobandtube.com/whole-house-rewiring/) or [partial replacement](https://deckerbostonknobandtube.com/partial-knob-and-tube-replacement/), not a substitute for one. ## What happens on the first visit The first visit asks two questions: is the existing panel or fuse box fit to keep, and is the service big enough for the house as it will be used. They have different answers more often than owners expect. ### The panel inspection The electrician opens the fuse box or panel and checks what is in it. That means signs of heat at fuse sockets and terminals, corrosion, fuses or breakers larger than the wire they protect, more than one wire under a terminal made for one, and how many spaces are left. The circuits leaving the panel are traced far enough to say which are knob and tube, cloth-sheathed cable or later cable. The [knob and tube inspection](https://deckerbostonknobandtube.com/knob-and-tube-inspection/) covers the circuit tracing in more depth. ### The load calculation Then comes a load calculation: the house’s lighting and outlet load, the kitchen and laundry, heating and cooling, water heating and anything planned, such as a heat pump or EV charger, worked through the code’s method for dwellings. The result is a service size the house needs, which can be smaller than owners assume. A calculation that fits the existing service means a panel swap may do; one that doesn’t means a service upgrade and the utility. ### What you get back You get a written recommendation: keep, replace or add a sub-panel, and whether the service changes. It sits in the same scope as the circuit work, so the panel’s spaces match the circuits being added and nobody buys a panel twice. ## Why knob and tube jobs so often reach the panel A rewire can outgrow an old panel in three different ways, and any one of them is enough. ### Arc-fault breakers need spaces Massachusetts goes further than the base code on arc-fault protection. Its version of 210.12(B) covers every 120 volt, 10, 15 and 20 amp branch circuit supplying outlets or devices in a dwelling unit, not a list of rooms. Each new circuit from a rewire needs that protection, which in practice means a breaker panel with room for it. A fuse box offers neither the breakers nor the spaces. When an existing circuit is modified, replaced or extended, the NEC’s own arc-fault provision applies, and Massachusetts leaves it as written. ### Overfusing and old protection Fuses were made to match the wire, but a screw-in fuse of any size fits most old sockets. Where a knob and tube circuit kept blowing its fuse, a larger fuse let the circuit run hotter than the wire is rated for, without anything opening. The panel inspection compares every fuse or breaker with the wire it protects. Overfusing found there is a reason to treat the circuit itself as suspect, not only the fuse. The [guide to how many amps knob and tube can handle](https://deckerbostonknobandtube.com/guide/knob-and-tube-max-amps/) explains the limits of those old conductors. ### More circuits than the old layout had A rewire usually adds circuits: separate kitchen, bath and laundry circuits, split bedroom circuits and outlets where cords used to run. The panel has to hold all of them, and the service has to carry their combined load. Local permit records show the pairing is common. Of the 155 [Cambridge](https://deckerbostonknobandtube.com/service-areas/cambridge/) electrical permits naming knob and tube, 41 also mention a service or panel; in [Somerville](https://deckerbostonknobandtube.com/service-areas/somerville/) it is 35 of 181. A 2017 Brighton permit reads simply “rewire knob and tube install 60 amp panel.” ## What a new panel doesn’t do Changing the panel removes no knob and tube, and the Massachusetts code does not make it. Rule 3 of 527 CMR 12.00 lets an installation be modified without bringing the rest of it into compliance, and the state’s interpretation committee has said a service can be replaced while knob and tube circuits stay in place. That is useful when the budget forces a choice, but it means a new panel alone won’t answer an insurer’s or Mass Save’s question about old wiring. > One job or two > > If a panel is replaced now and the rewire follows later, ask for a written list of which breakers still feed knob and tube. The next electrician, the insurer and a future buyer will all ask the same question. The [guide on whether a panel upgrade removes knob and tube](https://deckerbostonknobandtube.com/guide/does-a-panel-upgrade-remove-knob-and-tube/) covers that question in full. ## When the service itself changes A service upgrade replaces the meter socket, the service-entrance conductors and the main panel, and it brings in the utility. ### Eversource, National Grid and Belmont Light In Boston, Cambridge, Somerville, Brookline and Newton the utility is Eversource, which handles new and upgraded services through a work request and expects the municipal wiring inspection to be done, with the inspector calling the approval in. In [Medford and Malden](https://deckerbostonknobandtube.com/service-areas/medford-malden/) it is National Grid, where the licensed electrician confirms the upgrade and the customer submits an electric service request form. National Grid lists simple connections at no charge and infrastructure changes as possible extra cost. [Belmont](https://deckerbostonknobandtube.com/service-areas/belmont/) is served by the town’s own light department, Belmont Light, which has its own process. ### The outdoor disconnect rule The NEC’s outdoor emergency disconnect rule is narrowed in Massachusetts. It reaches one- and two-family dwellings, new buildings of double occupancy and two-family units newly created from a one-family, and it does not apply when only the meter socket, service-entrance conductors, main breaker or related raceways are replaced. On most existing houses getting a new service, that exception is what governs, and the inspector confirms it per address. ### Historic districts and visible equipment A new mast, meter or service entry is exterior work. In the [Back Bay](https://deckerbostonknobandtube.com/service-areas/back-bay-beacon-hill-south-end/) Architectural District, the commission’s guidelines say no electrical equipment goes on primary elevations, attachments are made between the first and second stories on the rear, wiring and equipment should be black and connections to individual units are made inside the building. Similar review applies to visible exterior work in other Boston districts, so the design review goes on the schedule before the utility request. Panel, service or both? Start with the load calculation and a look at what the old fuse box is protecting. Get an Estimate (617) 405-3599 ## Permit, price and paperwork The permit is a small share of the cost; the service work and the circuits moved over make up most of it. ### The permit In Boston, [Inspectional Services](https://www.boston.gov/permitting/permits/electrical-permit) charges a $20 application fee plus $0.25 per amp for a new or upgraded service up to 240 volts. A 200 amp service therefore carries a $70 fee and a 100 amp service $45. Work that doesn’t change the service is charged at $1 per fixture, plug or outlet plus $5 per meter. Only a licensed contractor may apply, and work may not begin before the permit is issued. The [Boston permit guide](https://deckerbostonknobandtube.com/guide/boston-electrical-permit-for-rewiring/) covers the other cities. ### The price Upgrading a fuse box to a 200 amp breaker panel together with the service work falls in a typical Massachusetts range of $3,000 to $6,500; a panel-only swap costs less and utility charges are extra. Labor is a part of it: electricians in the Boston metro earn a median $38.42 an hour against $30.38 nationally, according to the Bureau of Labor Statistics. A wage is not a billing rate, which also covers insurance, licensing, vehicles and overhead. The [panel upgrade cost guide](https://deckerbostonknobandtube.com/guide/electrical-panel-upgrade-cost-boston/) breaks the range down, and the [cost estimator](https://deckerbostonknobandtube.com/tools/knob-and-tube-cost-estimator/) shows how a service change moves a rewire budget. ### The paperwork When the job is done you should hold the closed permit, a labeled panel schedule and, where the utility was involved, confirmation that the new service was energized after the inspector’s approval. In a multi-family building, each unit’s panel gets its own schedule, which the [triple-decker rewiring](https://deckerbostonknobandtube.com/triple-decker-rewiring/) page covers. ## What's included - An inspection of the existing panel or fuse box: condition, heat damage, fuse and breaker sizes against the wire they protect, and spare spaces - A load calculation from the house's actual and planned loads, so the service size is chosen, not assumed - A written choice between a panel swap on the existing service, a service upgrade, or a sub-panel for one unit or floor - Arc-fault breakers for the branch circuits, and ground-fault protection where Massachusetts requires it - Grounding and bonding at the service checked and brought up to the current requirement for the new equipment - The electrical permit filed by the licensed electrician, with the utility's work request or service form handled in order - Circuits moved to the new panel and tested, with a labeled panel schedule - A written note of which circuits on the new panel still run on knob and tube, if any ## Panel swap, service upgrade or sub-panel | | Panel swap on the existing service | Service upgrade with a new panel | Sub-panel for a unit or floor | | --- | --- | --- | --- | | Fits when | The load calculation shows the service is big enough, but the fuse box or panel has no room or is in poor shape | The calculation exceeds the service, or new heat pumps, cooking or EV charging are planned | One apartment or floor needs more spaces and the main service has capacity | | What changes | The panel and breakers; meter and service cable stay | Meter socket, service-entrance conductors and main panel | A new panel fed from the main, close to the circuits it serves | | Utility involved | No | Yes: Eversource, National Grid or Belmont Light | No | | Boston permit fee basis | Per fixture, plug or outlet, plus per meter | $0.25 per amp on the new service | Per fixture, plug or outlet, plus per meter | | Exterior work | None | Mast, meter or entry may change; historic districts review visible changes | None | | What it leaves alone | Every branch circuit, including any knob and tube | Every branch circuit, including any knob and tube | Everything outside the unit or floor it serves | ## Related resources Cost Guide How much does an electrical panel upgrade cost in Boston? What Boston-area owners budget to replace a fuse box or small service, why quotes for the same house can be thousands apart, and which parts of the price come from public rules. Decision Guide Does a panel upgrade remove knob and tube? Swapping a fuse box for breakers changes what protects the circuits, not the wire inside the walls. Here is what that means for code, insurers, Mass Save and your budget. 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. Learn How does a Boston electrical permit for rewiring work? Every knob and tube rewire in Boston runs through one permit office, one fee formula and two state rules about when walls can close. Here is the sequence from filing to final sign-off. 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. ## 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 Gloved hand at an old gray fuse box on a painted basement wall New breaker panel with its door closed on a plywood backboard in a fieldstone basement New electric meter and service conduit on the painted clapboard side wall of an older Boston house Inside a new breaker panel with two columns of breakers and new cables Size the panel from the house, not the habit A load calculation and a look at the wiring decide whether you need a new panel, a bigger service or neither. Get an Estimate (617) 405-3599 ## Fuse Box and Panel Upgrades questions ### Can the fuse box stay if the knob and tube is being replaced? Sometimes, but rarely for long. Massachusetts requires arc-fault protection on every 120 volt, 10, 15 and 20 amp branch circuit supplying outlets or devices in a home, and new circuits need somewhere to land. An old fuse box has no spaces for arc-fault breakers and usually no room to add circuits, so most rewires plan the panel at the same time. The decision is made from the fuse box's condition and the circuit count, not age alone. ### Does a service upgrade change how the house is grounded? It brings the grounding under review. When the service equipment is replaced, the grounding electrode connection and the bonding of water and gas piping are checked against the current code for the new equipment. Older houses can have a ground clamp on a water pipe that was later replaced with plastic, or no bonding jumper around the water meter. None of that adds a ground wire to old knob and tube circuits, which stay ungrounded until they are replaced. ### Does a new panel in Massachusetts need an outdoor emergency disconnect? Often not on an existing house. The Massachusetts version of the rule applies to one- and two-family dwellings and to new or newly subdivided ones, and it does not apply when only the meter socket, service-entrance conductors, main breaker or related raceways are replaced. As written, the rule doesn't list three-family buildings. The inspector confirms which requirement applies at each address before the equipment is ordered. ### What does it mean when a fuse is bigger than the wire it protects? It is called overfusing, and it removes the protection the fuse was there to give. On a knob and tube circuit meant for a 15 amp fuse, when fuses kept blowing, owners sometimes screwed in 20 or 30 amp fuses, which let the wire carry more current than it can safely handle, so it heats inside the wall without the fuse ever opening. Don't change fuse sizes yourself; an electrician checks every fuse against its wire. ### What does a fuse box to breaker panel upgrade cost alongside a rewire? Upgrading a fuse box to a 200 amp breaker panel together with the service work falls in a typical Massachusetts range of $3,000 to $6,500. A panel swap on an adequate existing service costs less, and any utility charges are separate. The spread comes from the meter socket and service cable, an overhead or underground feed, where the panel sits, grounding and bonding, and how many circuits move over. ## Related services ### Whole-House Rewiring → Every branch circuit replaced with new grounded cable, for houses where knob and tube, cloth cable and old splices are mixed through the walls. ### Partial Replacement → The circuits still on knob and tube replaced from the panel to the last device, with a written record of anything left for a later phase. ### 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.