Basement Finishing Cost in Boston (2026)
Average cost in Boston
$16,245 – $81,225
$50 – $120 per sq ft
In Boston, the average is $40,385 and most projects cost between $16,245 and $81,225, or about $50 – $120 per sq ft. Prices are before tax and based on 8 sources.
Cost Breakdown
ItemizedSkilled trades and general labor
40%
Drywall, flooring, and finishes
35%
Wiring, lighting, and rough-ins
15%
Moisture barriers and sump pumps
7%
City of Boston ISD fees and plans
3%
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 project
LiveYour estimate in Boston
Likely range $18,173 – $81,225
- Labor40%$16,154
- Materials35%$14,135
- Electrical & Plumbing15%$6,058
- Waterproofing & Prep7%$2,827
- Permits & Design3%$1,212
Basic (rec room)
$28,094
Standard (bedroom + bath)
$40,385
Premium (full suite)
$57,592
Calibrated to 8 researched sources for Boston. Before tax. Real quotes vary with site conditions.
📈Price Momentum
Year-over-year~1 year ago
$38,243
Today
$40,385
Basement Finishing in Boston is ↑ 5.6% compared to roughly a year ago — about $2,142 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 providersBoston Pro Quality Services, Inc.
32 Ashton St, Everett, MA 02149, USA
55 reviews
Sun Shore Construction
163 Highland Ave #1051, Needham, MA 02494, USA
48 reviews
X'CLUSIVE RENOS & REMODELING LLC
17 Blakeville St, Boston, MA 02121, USA
42 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
Homeowners in the Greater Boston area can expect a return on investment (ROI) of approximately 65% to 75%, as finished basements significantly increase usable square footage in a high-density market.
Adding a full bathroom typically increases the project cost by $7,150 to $17,900, depending on whether a sewage ejector pump is required for below-grade drainage.
Yes, if the finished space includes a legal bedroom, Massachusetts state code requires an egress window. Installation in Boston's older foundations typically costs between $3,500 and $6,000.
The Boston Inspectional Services Department (ISD) typically requires a Long-Form permit for finishing unfinished space. Fees are generally $50 plus $10 per $1,000 of the estimated project cost.
📊Our Methodology
How we collect dataAggregated from 5+ 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: 1 months 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.