Insulation cost in Boston: what owners paid (2023 survey)
Boston owners paid a median $1,800 for insulation: $300 above the U.S. median, tied for fourth-highest of 6 big metros (Census Bureau, 2023). When owners hired it out, the middle half paid $1,000 to $3,000.
What Boston owners paid
$1,800
This is historical spending: work done in about 2021 to 2023 on owner-occupied homes, reported in the 2023 survey.
Margin of error ±$830: at 90% confidence the Boston median lies between $970 and $2,630.
Hired out: $2,500 typical, from 43 hired-out jobs in the survey sample.
How Boston compares
- U.S. median, same work
- $1,500
- Rank, highest first
- Tied at 4 of 6
Boston: $1,800. The big-metro medians run from $1,000 to $2,857.
9 of the 15 metros have no published figure for this work, so the rank counts the other 6.
What Boston insulation permits declared
Boston’s building permits for insulation on one- and two-family houses issued from October 2025 to September 2026 declared a median of $5,800; the middle half declared $3,400 to $9,500 (1,163 permits).
This is the cost of the work as the applicant estimated it on the permit, not an invoice or a final price. It counts every short-form insulation permit on a one- or two-family house, the city’s own category for this work. Most are weatherization jobs, air sealing with attic or wall insulation, and about one in five names Mass Save, the energy-efficiency program of the state’s utilities: the permit gives the value of the work, not what the owner paid after the Mass Save incentive. Set it beside your written quotes.
Mass Save takes 75% off the insulation it approves, 100% for households that qualify by income, and does targeted air sealing at no cost. If the whole of a $5,800 job, the median here, were insulation Mass Save approves, its 75% off would leave about $1,450 to the owner. In a two-family house with a rented unit, Mass Save’s offer for landlords takes 100% off the approved insulation in the rented unit; the unit the owner lives in gets the offers above. Where the two units are condominiums with a residential heating meter, each can get up to 100% off when both owners take part, and up to 75% when only one does.
The permits’ median is well above the $1,800 median from the Census survey shown above. The survey counts every job owners reported for work done in about 2021 to 2023, do-it-yourself work and small jobs included; these are permits issued from October 2025 to September 2026, each job priced by its applicant.
Source: City of Boston, Approved Building Permits (Analyze Boston), read . Incentives: Mass Save, “The Smart Path to Energy Savings”, ; Mass Save, “Insulation and Air Sealing”, ; Mass Save, “No-cost Home Energy Assessments for Landlords (1-4 units)”.
No published figure: Atlanta, Chicago, Detroit, Los Angeles, Miami, Phoenix, Riverside, San Francisco, Seattle.
- Seattle$4,000$2,000–$6,500
- Washington DC$2,900$1,500–$5,000
- Boston$2,500$1,000–$3,000
A metro is shown when at least 30 hired-out jobs in the survey sample stand behind it.
What it covers
Adding or replacing insulation anywhere in the house: attic, walls or floors.
The Census category is “Insulation” within “Interior Additions and Replacements”: what Boston-area homeowners told the Census Bureau they paid, every size of job together.
Before you compare quotes
Ask every contractor to price the same scope, in writing. A quote outside the hired-out range above is a reason to ask what it covers, not proof that it is wrong. Which surfaces, removal, access and air-sealing tasks are included?
Then put the quotes in your project budget worksheet to see each one's scope beside its price.