Basement Finishing Cost in Boston (2026)
Average cost in Boston
US$15,000 — US$135,000
US$50 — US$120 per sq ft
Cost Breakdown
ItemizedLicensed trades and general labor
35%
Drywall, flooring, framing, and fixtures
45%
Boston ISD building, electrical, and plumbing fees
5%
Architectural drawings and layout design
5%
Buffer for moisture issues or code upgrades
10%
Sales Tax at 6.25%
📋What's Included
ScopeTypically Includes
- Framing & drywall
- Basic flooring (LVP or carpet)
- Electrical (outlets & lighting)
- Egress window (if required)
- Painting
- Basic bathroom rough-in
Typically Excludes
- Full basement bathroom
- Built-in bar or kitchen
- Home theater wiring
- Waterproofing (separate cost)
- Permits & inspections
Assumes an unfinished basement with existing concrete floor and basic utilities.
🧮Estimate Your Cost
InteractiveEstimated Cost
US$30,624 — US$45,936
Based on 9 sources and market data for Boston. Actual costs may vary depending on specific project requirements.
📈Price Momentum
Year-over-year~1 year ago
US$50,902
Today
US$53,752
Basement Finishing in Boston is ↑ 5.6% compared to roughly a year ago — about US$2,850 more on the average project.
Comparison derived from the year-over-year change rate, not a month-by-month price index. We don't store historical snapshots yet — when we do, this will become a real time series.
🏢Top Basement Finish Contractors in Boston
Verified providersX'CLUSIVE RENOS & REMODELING LLC
17 Blakeville St, Boston, MA 02121, USA
42 reviews
Greater Boston Contractors
1309 Beacon St Ste 300, Brookline, MA 02446, USA
29 reviews
Provider data sourced from public business directories. Ratings and reviews are public and may change. LookupCost is not affiliated with listed providers.
💬What People Actually Paid
Community❓Common Questions
Yes. The Boston Inspectional Services Department (ISD) requires building permits for any structural work, plus separate permits for electrical and plumbing. Fees typically start at $50 plus $10 per $1,000 of estimated project value.
Adding a full bathroom in a Boston basement typically costs between $7,150 and $17,900, depending on whether existing plumbing lines need to be relocated or if a sewage ejector pump is required.
Homeowners in the Greater Boston area can expect a return on investment (ROI) of approximately 65% to 75% upon resale, as finished square footage is highly valued in the competitive local market.
To meet Massachusetts building codes for a legal bedroom, an egress window is required. This typically costs between $3,500 and $6,000, which includes excavating the foundation and installing the window well.
📊Our Methodology
How we collect dataAggregated from 7+ verified web sources and cost databases
Licensed contractor estimates and regional cost guides
Government construction and labor statistics
Community-reported project costs and reviews
Last data collection: 2 weeks ago. Updates run weekly. All costs in USD.
About this data
Cost figures are estimates synthesized from public market data using AI research and refreshed regularly. Real project costs vary by scope, materials, contractor, and site conditions. Always get verified quotes from licensed contractors for your specific project.
Spotted bad data? Let us know — we'll review and update.