How Much Does Room Addition Cost?
Updated for 2026 — national average costs with state-by-state breakdowns
What Does Room Addition Include?
A room addition extends your home's footprint by building a new room — bedroom, family room, home office, or in-law suite. It's one of the most expensive renovations but adds significant living space and value.
The national average cost for room addition is $45,000 per project. Most homeowners pay between $20,000 and $80,000, though costs can vary significantly based on your location, the scope of work, and other factors outlined below.
What Affects the Price?
Size
Small (100 sq ft): $15,000-$25,000. Average (200 sq ft): $30,000-$50,000. Large (400+ sq ft): $60,000-$100,000+
Room Type
Basic bedroom: $20,000-$40,000. Bedroom + bathroom: $35,000-$65,000. In-law suite: $50,000-$100,000+
Per Sq Ft
Budget: $80-$150/sq ft. Mid-range: $150-$250/sq ft. High-end: $250-$400+/sq ft
Key Cost Factors
- ✓Room size
- ✓Room type and purpose
- ✓Foundation type
- ✓Roofline integration
- ✓Plumbing and electrical
- ✓Permits and architectural plans
- ✓Finishes and materials
💡 Tips to Save Money
- 1.A bump-out (extending an existing room 2-4 feet) costs $5,000-$15,000 — much less than a full addition
- 2.Building over an existing garage or patio saves on foundation costs
- 3.A dormer addition (expanding attic space) costs 30-50% less than a ground-floor addition
- 4.Act as your own general contractor if you have experience — save 15-25% on management fees
📈 Room Addition Cost Trends (2020–2024)
Prices have increased +17.7% over the last 5 years
| Year | National Avg | YoY Change |
|---|---|---|
| 2020 | $38,223 | — |
| 2021 | $39,828 | +4.2% |
| 2022 | $42,417 | +6.5% |
| 2023 | $43,605 | +2.8% |
| 2024 | $45,000 | +3.2% |
Based on national averages adjusted for annual inflation. Actual costs vary by location and project scope.
Room Addition Cost by State
Costs vary significantly by state due to labor rates, cost of living, and local market conditions. Click any state for a detailed breakdown.
| State | Low | Average | High |
|---|---|---|---|
| Alabama | $16,400 | $36,900 | $65,600 |
| Alaska | $25,600 | $57,600 | $102,400 |
| Arizona | $19,000 | $42,750 | $76,000 |
| Arkansas | $16,000 | $36,000 | $64,000 |
| California | $27,000 | $60,750 | $108,000 |
| Colorado | $21,600 | $48,600 | $86,400 |
| Connecticut | $24,400 | $54,900 | $97,600 |
| Delaware | $21,000 | $47,250 | $84,000 |
| Florida | $19,600 | $44,100 | $78,400 |
| Georgia | $18,000 | $40,500 | $72,000 |
| Hawaii | $28,400 | $63,900 | $113,600 |
| Idaho | $18,400 | $41,400 | $73,600 |
| Illinois | $21,000 | $47,250 | $84,000 |
| Indiana | $17,600 | $39,600 | $70,400 |
| Iowa | $17,200 | $38,700 | $68,800 |
| Kansas | $17,000 | $38,250 | $68,000 |
| Kentucky | $16,800 | $37,800 | $67,200 |
| Louisiana | $17,400 | $39,150 | $69,600 |
| Maine | $20,400 | $45,900 | $81,600 |
| Maryland | $23,000 | $51,750 | $92,000 |
| Massachusetts | $26,000 | $58,500 | $104,000 |
| Michigan | $18,400 | $41,400 | $73,600 |
| Minnesota | $20,400 | $45,900 | $81,600 |
| Mississippi | $15,600 | $35,100 | $62,400 |
| Missouri | $17,400 | $39,150 | $69,600 |
| Montana | $19,000 | $42,750 | $76,000 |
| Nebraska | $17,600 | $39,600 | $70,400 |
| Nevada | $20,400 | $45,900 | $81,600 |
| New Hampshire | $22,400 | $50,400 | $89,600 |
| New Jersey | $25,000 | $56,250 | $100,000 |
| New Mexico | $18,000 | $40,500 | $72,000 |
| New York | $26,400 | $59,400 | $105,600 |
| North Carolina | $18,000 | $40,500 | $72,000 |
| North Dakota | $18,000 | $40,500 | $72,000 |
| Ohio | $18,000 | $40,500 | $72,000 |
| Oklahoma | $16,600 | $37,350 | $66,400 |
| Oregon | $22,000 | $49,500 | $88,000 |
| Pennsylvania | $20,400 | $45,900 | $81,600 |
| Rhode Island | $23,000 | $51,750 | $92,000 |
| South Carolina | $17,400 | $39,150 | $69,600 |
| South Dakota | $17,000 | $38,250 | $68,000 |
| Tennessee | $17,200 | $38,700 | $68,800 |
| Texas | $18,600 | $41,850 | $74,400 |
| Utah | $19,000 | $42,750 | $76,000 |
| Vermont | $21,600 | $48,600 | $86,400 |
| Virginia | $21,000 | $47,250 | $84,000 |
| Washington | $23,000 | $51,750 | $92,000 |
| West Virginia | $16,000 | $36,000 | $64,000 |
| Wisconsin | $18,800 | $42,300 | $75,200 |
| Wyoming | $18,400 | $41,400 | $73,600 |
Frequently Asked Questions
Does a room addition increase home value?
Yes, though ROI varies: 50-65% for a standard room addition, 60-75% for a bedroom + bathroom addition. The value also depends on whether the addition fits the neighborhood — over-improving for your area yields lower returns.
How long does a room addition take?
Typical timeline: 2-4 weeks for permits and planning. 8-16 weeks for construction. Total: 3-5 months. Complex additions with full bathrooms or custom features can take 6-12 months.
🏙️ Room Addition Cost by City
Compare room addition costs in the most popular US cities:
View all 219 cities →
Related Cost Guides
💬 What Did You Pay?
Real costs reported by homeowners for Room Addition
Recent Reports
📐 Room Addition Cost Calculator
Get a personalized estimate based on your project details
Get Free Renovation Estimates
Connect with licensed contractors for your project.
🔍 Get Free Quotes from Local Pros
Compare prices from pre-screened contractors in your area. Free, no-obligation estimates.
* CostWhale may earn a commission. This doesn't affect our pricing data or recommendations.
💰 Get Weekly Cost-Saving Tips
Join 10,000+ smart homeowners. Unsubscribe anytime.