What ADUs Costs in Boston — Low, High and Typical

Last updated October 5, 2026

Expect adu in Boston to land in the $1,418–$4,396 per job band. A typical project runs about $2,497.

The Massachusetts market sets a baseline, but Boston neighbourhoods vary. Access, parking and the age of the building can each add to a adu bill.

Typical cost at a glance

United States planning figures, per job
Level	Price
Low	~$1,418
Typical	~$2,497
High	~$4,396

Cost by type

Type	Low	Typical	High
Baseline transaction cost	~$1,418	~$2,907	~$4,396
Below-median price scenario	~$1,163	~$2,626	~$4,088
Above-median price scenario	~$1,588	~$3,827	~$6,066
Lender and government fees	~$170	~$679	~$1,187
Competitive or fast-moving market	~$1,730	~$4,206	~$6,682

All figures per job.

Timing your adu

Timing changes what you pay for adu. Demand peaks around holidays, seasonal deadlines and the start of the busy season, and prices follow. Booking in a quieter window is one of the few levers that lowers the figure without cutting scope.

Getting quotes for adu

A good adu quote lists what is included, what is excluded and how long the price is held. If it does none of those, ask for a revised version.

Budgeting for adu

Set aside the typical figure, near $2,497 per job, and treat anything closer to $1,418 as a bonus rather than a target. For adu, the middle of the range is the realistic number.

What ADUs typically costs

ADUs does not carry one published price. Across Boston, most jobs fall between $1,418 and $4,396 per job, and the number in between, about $2,497, is the fairest single figure to plan around.

How to compare quotes for adu

For adu, a fair comparison means identical scope. If one quote includes permits and cleanup and another does not, the cheaper total may not be cheaper at all.

What moves the price of adu

What pushes adu toward the top of its range? Premium materials, awkward access, urgent scheduling, extra permits and disposal. Each is optional to a degree, and each should be itemised before you compare totals.

Frequently asked questions

How much does adu cost?

Most adu falls between $1,418 and $4,396, with a typical figure near $2,497 per job. The low end is a straightforward job with no surprises; the high end covers complex scope, premium materials or urgent timing. It is worth testing that against a couple of quotes in Boston.

What affects the price of adu?

No single factor decides it — scope, materials, access and timing all move the total, and the biggest swings usually come from access and scheduling. Local providers in Boston can confirm how that applies to your area.

Is ADUs cheaper in smaller cities?

Often, but not always. Smaller markets can carry a travel or availability premium that offsets a lower local rate, so it is worth checking a nearby city before assuming the lowest published figure applies to you. In Boston, that is worth confirming with a local provider before you commit.

How many quotes should I get for adu?

Two or three written quotes are enough to see the real market range. Compare the same scope side by side, and ask each provider what is excluded and what would change the price after the quote is accepted. The answer can shift with the Boston market, so check locally.

Keep comparing

Related categories

Real Estate

Related costs

Cities in this region

These are planning ranges drawn from public price data and market research. They are not a quote, an offer or financial advice, and your actual price depends on the provider, the location and the scope of the work.