Accessory Dwelling Unit (ADU) Construction in Boston, MA — Costs $96,810 to $564,725
What does accessory dwelling unit (adu) construction cost in Boston? Average $242,025, ranging $96,810–$564,725. Labor runs $53.91/hr locally — 61% above the national average. Free breakdown with material + labor split.
Boston, MA Market
+61% vs nationalLabor Rate
$53.91/hr
Material Index
143
Avg Permit Cost
$3,166
Median Home Price
$512,971
As one of the largest metros in Massachusetts, Boston has a competitive contractor market with hundreds of licensed professionals. This typically gives homeowners more leverage on pricing, though high demand for renovations can offset that advantage. At 61% above the national average, Boston is one of the more expensive markets for home improvement — driven primarily by above-average labor rates in the region. With a median home price of $512,971, this accessory dwelling unit (adu) construction represents just 47.2% of typical home value — a relatively small investment that can significantly boost curb appeal or functionality.
Low Estimate
$96,810
National: $60,000
Mid-Range
$242,025
National: $150,000
High End
$564,725
National: $350,000
Per Sq Ft
$403
National: $250
Accessory Dwelling Unit (ADU) Construction Cost Calculator for Boston
Adjusted for Boston's labor rate ($53.91/hr) and material costs (index 143).
Mid-grade materials, good quality fixtures, standard options.
Estimated Total in Boston
$242,025
Based on 200 sq ft at mid quality, adjusted for Boston market rates.
Local Cost Breakdown
At Boston's average rate of $53.91/hr (80% above national avg)
Material cost index 143 (43% above national baseline of 100)
Accessory Dwelling Unit (ADU) Construction vs. Home Value in Boston
| Metric | Boston | National Avg |
|---|---|---|
| Accessory Dwelling Unit (ADU) Construction (Mid-Range) | $242,025 | $150,000 |
| Median Home Price | $512,971 | $350,000 |
| Project as % of Home Value | 47.2% | 42.9% |
| Estimated ROI | 80% | 80% |
| Median Household Income | $92,000 | $75,000 |
What Affects the Price in Boston
- 1Local labor rates ($53.91/hr in Boston)
- 2Material cost index (143 vs national 100)
- 3Attached vs detached
- 4Size and bedroom count
- 5Kitchen and bath quality
- 6Local ADU regulations
Popular Upgrades
- Full kitchen
- Separate entrance
- Solar panels for energy independence
Other Projects in Boston, MA
Second Story Addition
$322,700
Room Addition
$145,215
Swimming Pool Installation
$102,492
Garage Addition
$88,743
Home Addition
$127,612
Inground Swimming Pool
$101,299
Attic Conversion
$89,752
Swimming Pool Construction
$81,593
Accessory Dwelling Unit (ADU) Construction in Other Massachusetts Cities
Planning a Accessory Dwelling Unit (ADU) Construction in Boston
Building permits are typically required for a accessory dwelling unit (adu) construction in Boston. The average permit fee in this area is $3,166, though costs vary based on project scope. Permit fees in this market are above average — factor them into your total budget. Plan for 6-18 months from start to finish.
A accessory dwelling unit (adu) construction is a complex project best left to licensed professionals. In Boston, skilled contractors charge an average of $53.91/hr, and the specialized nature of this work means cutting corners on labor can lead to costly rework.
With a median household income of $92,000, many Boston residents can budget for this project through savings. The mid-range cost of $242,025 represents 263% of the typical household's annual income.
Accessory Dwelling Unit (ADU) Construction — National Guide
See the full national cost guide with DIY tips, cost factors, and ROI analysis.
All Construction Costs in Boston
View labor rates, material costs, and project estimates for Boston, MA.
Explore All Project Cost Guides
Compare costs across 120+ home improvement projects in 3,636 cities nationwide.
View All Project Costs