# Knob and Tube Replacement in Dorchester's Three-Deckers and Two-Families > Knob and tube replacement in Dorchester three-deckers: floor-by-floor rewiring, common hallway circuits, Boston ISD permits, Eversource and Mass Save help. URL: https://deckerbostonknobandtube.com/service-areas/dorchester/ Boston Inspectional Services Department issues the electrical permit (City of Boston) Eversource electric utility 65 electrical permits describing a rewire in Dorchester ZIPs, Nov 2021 to Oct 2026 02122, 02124, 02125 ZIP codes ## What usually starts a rewire in Dorchester ### The stair lights still run on the old wiring Where the units were updated over the years, the front and back stair lighting is often the circuit nobody owned. It can still be knob and tube feeding from one apartment or a house panel. ### One floor was renovated, two were not An owner who redid the first-floor kitchen may have new wiring downstairs and original circuits on the second and third floors, all sharing one basement and one service. ### A Mass Save visit stopped the insulation In a three-family, an energy assessment that finds knob and tube can hold up insulation for the whole building until an electrician certifies the work areas. ### Three meters and a service upgrade When a rewire adds circuits to three units, the service and meter bank may need to grow, which brings an Eversource work request into the schedule. ## Services in Dorchester ### 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. ### 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. ### Knob and Tube Inspection → A licensed electrician traces every circuit, finds which old runs still carry power and puts the findings and a recommended scope in writing. ### 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. ### Insulation Barrier Work → The licensed electrician's work and certification that clear a Mass Save knob and tube barrier, so recommended insulation can go in. ### 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. Knob and tube replacement in Dorchester is rarely one family’s project. Most of the neighborhood’s pre-war housing is two- and three-family buildings, so the old wiring usually belongs to several homes, a shared stairway and one basement. [Decker Boston Knob and Tube](https://deckerbostonknobandtube.com/) arranges that work across Dorchester, from Savin Hill and Fields Corner to Codman Square, Ashmont and Lower Mills, carried out by licensed and insured electrical contractors. It begins with a [knob and tube inspection](https://deckerbostonknobandtube.com/knob-and-tube-inspection/) that sorts out which circuits are live and which unit each one serves. ## Why a Dorchester rewire is a building, not a house Dorchester holds Boston’s densest concentration of three- and four-unit buildings. Census figures put 43.4% of housing units in ZIP 02122 and 44.3% in 02125 in buildings of that size, against 23.5% citywide, and 60.0% of 02122’s units date from before 1940. The Boston Preservation Alliance estimates that about 15,000 triple-deckers went up in Boston between 1880 and 1930, nearly all wood-frame, following the trolley lines into Dorchester, Roxbury and Mattapan. That building era overlaps the decades when knob and tube was standard, which is a reason to check, not proof of what a given building has. What it does mean is that a full job here is a [triple-decker rewire](https://deckerbostonknobandtube.com/triple-decker-rewiring/): three dwelling units, often three meters, a common stair, and residents living on the floors not being worked on. ## Three units, three meters, one stairwell The decision in a Dorchester building is less about whether to rewire than about how to divide the work so each household keeps power and each floor ends up with a clear record. ### Floor by floor Each floor is usually its own dwelling unit, so each is usually its own stage. Where one unit was already updated, the job on that floor may be a [partial replacement](https://deckerbostonknobandtube.com/partial-knob-and-tube-replacement/) of whatever old circuits remain. The basement carries every unit’s circuits back to the service, and the top floor depends on the attic or, under a flat roof, on routes from below. Boston’s permit records show the pattern: a 2011 Dorchester permit in a one-to-three-family building reads “replace one water damaged knob and tube circuit on second floor. add sub panel on second floor for replacement wiring.” ### The common hallway rule The front and back stairs are a separate scope. The Massachusetts electrical code makes an exception for existing three-family buildings: lighting in common areas on the same floor as a unit may be fed from equipment that serves one or more of the units. That can spare a three-decker a separate house panel just for the stair lights, though the layout is confirmed with the inspector building by building. ### The service and the meters Adding circuits to three units can outgrow the service. Another 2011 Dorchester permit reads “Upgrade existing electrical service from 100 to 200 amps. Remove knob and tube wiring.” Dorchester is Eversource territory, so a service change adds an Eversource work request to the schedule. The [panel and service upgrade page](https://deckerbostonknobandtube.com/electrical-panel-upgrade/) covers when that is needed, and the [Boston cost guide](https://deckerbostonknobandtube.com/guide/knob-and-tube-replacement-cost-boston/) shows how units, meters and a service change move the budget. ## How a Dorchester job usually runs The order follows the building, not a template, but most Dorchester jobs move through the same stages. - **The first call** collects the address, how many units there are, which are owner-occupied, and what started it: an insurer, a sale or a Mass Save assessment. - **The assessment** traces circuits from each meter and panel to the rooms and stairs they feed, so every unit’s scope and the common areas are written up separately. - **The licensed contractor files one Boston permit** for the work, and the households get the dates for each floor and for any service shutdown in advance. - **The rough-in inspection** happens before any wall or ceiling is closed. Massachusetts rules say new wiring can’t be covered until the inspector has seen it, within 72 hours of notice, weekends and holidays excluded. - **The finish** is a final inspection, a labeled panel schedule for each unit and a written summary of what was replaced and what, if anything, remains. The [living at home guide](https://deckerbostonknobandtube.com/guide/living-at-home-during-rewiring/) covers what each household can expect on its work days. Rewiring a Dorchester two- or three-family? Start with which units and which stairs still run on the old circuits. The scope follows from that. Get an Estimate (617) 405-3599 ## Permits, Eversource and Mass Save in Dorchester Dorchester follows the same rules as the rest of Boston, which keeps the paperwork simple. The [Boston Inspectional Services Department](https://www.boston.gov/permitting/permits/electrical-permit) issues electrical permits citywide, and a homeowner must hire a licensed contractor to apply. ISD’s fee is a $20 application fee plus $1 per fixture, plug or outlet and $5 per meter when the service stays the same, or $0.25 per amp for a new or upgraded service. The [Boston permit guide](https://deckerbostonknobandtube.com/guide/boston-electrical-permit-for-rewiring/) walks through it. Permit records point to how much rewiring goes on here. Between November 2021 and October 2026, 54 electrical permits in ZIPs 02122, 02124 and 02125 described a rewire, plus 11 in Grove Hall’s 02121, more than any other part of the city. The city’s open dataset appears to be missing many recent permits, so treat those counts as a floor. Mass Save often sets the deadline. An energy assessment that finds active knob and tube holds back insulation until a licensed electrician certifies the work areas, and in a three-family that can stall the whole building. Mass Save’s barrier incentive of up to $7,000 for moderate-income households covers 1 to 4 unit homes, so a three-decker qualifies by size; income and other conditions still apply. The [insulation barrier service](https://deckerbostonknobandtube.com/knob-and-tube-insulation-barrier/) and the [grants guide](https://deckerbostonknobandtube.com/guide/knob-and-tube-removal-grants-massachusetts/) cover how that works. ## South Boston, East Boston, Roxbury and Mattapan The same three-decker form continues past Dorchester’s edges, with the same permit office and utility, so these neighborhoods are covered here rather than on pages of their own. ### South Boston In 02127, 35.4% of housing units are in three- and four-unit buildings. The Preservation Alliance notes South Boston’s triple-deckers are mostly flat-roofed, so top-floor cable usually can’t cross a walk-in attic and has to come up from below or through small ceiling openings. ### East Boston East Boston’s 02128 has 40.0% of its units in three- and four-unit buildings and 53.2% built before 1940, close to Dorchester’s profile. The floor-by-floor approach and the common hallway rule apply the same way. ### Roxbury and Highland Park Roxbury’s 02119 had the highest share of electrical permits describing a rewire of any Boston ZIP between November 2021 and October 2026, 16 of 97. Parts of it sit in the Highland Park Architectural Conservation District, designated in 2022, where exterior work visible from a public way goes to the Boston Landmarks Commission before permits. Interior rewiring isn’t reviewed, but a new mast or meter bank on a visible wall may be. ### Mattapan Mattapan’s 02126 is 40.9% pre-1940, with 18.5% of units in three- and four-unit buildings and 22.2% in detached houses. A detached house there is closer to a standard [whole house rewire](https://deckerbostonknobandtube.com/whole-house-rewiring/) than to a multi-unit job. ## Neighborhoods, landmarks and routes - Savin Hill - Fields Corner - Codman Square - Ashmont - Adams Village - Uphams Corner - Meeting House Hill - Lower Mills - Neponset - Grove Hall ### Landmark districts - Highland Park Architectural Conservation District (Roxbury) ### Landmarks - Franklin Park (edge) - Dorchester Park - Ashmont station - JFK/UMass station - Pope John Paul II Park ### Routes - I-93 / Southeast Expressway - Dorchester Avenue - Morrissey Boulevard - MBTA Red Line (Ashmont branch) - Fairmount Line 1. 1. Back Bay, Beacon Hill & South End 2. 2. Belmont 3. 3. Brookline 4. 4. Cambridge 5. 5. Dorchester 6. 6. Jamaica Plain, Roslindale & West Roxbury 7. 7. Medford and Malden 8. 8. Newton 9. 9. Somerville Schematic, not to scale: close-together neighborhoods are spread out so each number reads. Planning a rewire in Dorchester? Start with which circuits are still live. The rest of the estimate follows from that. Get an Estimate (617) 405-3599 ## Dorchester questions ### What does knob and tube replacement cost for a Dorchester three-decker? There is no separate Dorchester price. 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, and larger, plaster-heavy or service-upgrade jobs can run well past it. A three-decker is priced from its own scope: how many units still have live knob and tube, the common stairs, the meters, and whether each floor gets a new sub-panel. ### Can the hallway lights in a Dorchester three-decker be fed from one of the apartments? Often, yes. The Massachusetts electrical code lets lighting in common areas on the same floor as a dwelling unit, in an existing three-family building, be supplied from equipment that serves one or more of the units. That means a rewire doesn't always need a separate house panel for the stair lights. The licensed contractor confirms the layout with the Boston inspector for each building. ### Do the people on the other floors have to move out while one floor is rewired? Usually not. A three-decker is normally rewired one floor at a time, and each unit keeps power on its own circuits while another floor is worked on. Shutdowns of the shared service or meter bank affect everyone, so they are scheduled ahead and kept short. The owner should give every household the dates in advance, and in winter the boiler controls have to stay powered. ### Does rewiring a house in Roxbury's Highland Park district need Landmarks approval? Interior rewiring is not what the Boston Landmarks Commission reviews. Exterior work visible from a public way inside its districts is, and a new service mast, meter bank or surface conduit can fall into that. If the job changes anything on the outside of the house, check with the Landmarks Commission before the electrical permit is filed. ### Is the top floor of a flat-roofed South Boston triple-decker harder to rewire? It can be. The Boston Preservation Alliance notes that South Boston's triple-deckers are mostly flat-roofed, which usually means no walk-in attic for running cable across the top floor. Routes then come up from below, through stacked closets and chases, or through small openings in the top-floor ceiling. The access plan from the first visit shows which applies and how much patching follows. ## Related guides 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. 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. Decision Guide Are there grants for knob and tube removal in Massachusetts? True grants are rare. The real help runs through Mass Save's insulation programs and a few city and state loans, and the order you apply in matters as much as which one you pick. ## Nearby service areas Boston Inspectional Services Department permits Jamaica Plain, Roslindale & West Roxbury The kitchen is new, the bedrooms are not Boston Inspectional Services Department permits Back Bay, Beacon Hill & South End A condo sale turned up old wiring Somerville Inspectional Services Department permits Somerville Upstairs is original, downstairs isn't