Quick Answer: A home addition costs $80–$250+ per square foot installed. A 200 sq ft bedroom runs $20,000–$50,000. Bathroom additions cost $25,000–$75,000. Materials range from $25–$130/sq ft depending on room type and quality. Labor runs $15–$25/sq ft using carpenter rates of $21.77–$31.75/hr nationally. Add $6,300–$12,000 for foundation, permits, architectural plans, HVAC extension, and electrical hookup. Enter your ZIP for location-specific pricing, plus Census-sourced local housing data showing how the addition cost compares to your area's median home value — essential for ROI planning.
Calculate how much a home addition costs. Select the room type, size, quality level, and ZIP code to get a location-specific estimate with a full breakdown of materials, labor, and fixed costs.
Home Addition Cost by Type
| Addition Type | Cost/Sq Ft | Typical Size | Total Range |
|---|---|---|---|
| Bedroom | $100–$250/sq ft | 200 sq ft | $20,000–$50,000 |
| Bathroom | $130–$300/sq ft | 75 sq ft | $25,000–$75,000 |
| Sunroom | $80–$200/sq ft | 200 sq ft | $15,000–$40,000 |
| Garage | $60–$150/sq ft | 400 sq ft | $20,000–$50,000 |
How Home Addition Cost Is Calculated
- Materials: Square footage × material rate per sq ft ($25–$130 depending on type and quality). Includes framing, sheathing, roofing, siding, insulation, drywall, flooring, and finish materials.
- Labor: Square footage × hours per sq ft × hourly rate × 1.5 burden. Bathroom additions require the most labor at 0.55 hr/sq ft due to plumbing and tile work.
- Fixed costs: Foundation/slab ($2,000–$3,500), permits ($1,000–$1,500), architectural plans ($800–$1,500), HVAC extension ($0–$2,000), electrical hookup ($800–$1,500), and plumbing rough-in ($3,000 for bathrooms).
- Contractor markup: 20% for general contractor overhead, profit, and project management.
Home Addition ROI by Type
| Addition Type | Avg Cost | Value Added | ROI |
|---|---|---|---|
| Bathroom Addition | $50,000 | $30,000–$35,000 | 60–70% |
| Master Suite | $75,000 | $41,000–$49,000 | 55–65% |
| Garage | $35,000 | $18,000–$21,000 | 50–60% |
| Sunroom | $30,000 | $13,500–$16,500 | 45–55% |
Formula Summary
Home Addition Cost Formula: Total cost includes materials (per sq ft), burdened labor, and fixed costs for foundation/permits/plans, multiplied by contractor markup.
Total = (A × M + A × H × R × 1.5 + F) × 1.20
where A = square footage, M = material cost/sq ft, H = labor hours/sq ft, R = hourly trade rate, 1.5 = labor burden, F = fixed costs, 1.20 = markup.
| Type | Material $/sq ft (mid) | Labor hr/sq ft | Fixed Costs |
|---|---|---|---|
| Bedroom | $65 | 0.45 | $9,500 |
| Bathroom | $85 | 0.55 | $11,500 |
| Sunroom | $55 | 0.35 | $6,500 |
| Garage | $40 | 0.30 | $6,300 |
Constants: Labor burden 1.5×. Contractor markup 20%. Fixed costs include foundation/slab, permits, architectural plans, HVAC extension, electrical hookup, and plumbing rough-in (bathrooms only). Trade: carpenters (SOC 47-2031). Rates from BLS OEWS May 2024, 393 metros.
Additional data: US Census Bureau ACS 5-Year Estimates for ZIP-level housing context (median home value, year built, rooms). BLS PPI lumber and composite construction materials index (monthly via FRED). Housing data used for addition ROI context.
Carpenters Hourly Rates by Metro (BLS OEWS May 2024)
| Metro | 25th %ile | Mean | 75th %ile |
|---|---|---|---|
| New York | $27.07 | $37.32 | $46.01 |
| Los Angeles | $26.91 | $36.97 | $47.02 |
| Chicago | $24.11 | $38.11 | $51.92 |
| Dallas | $20.33 | $24.01 | $26.76 |
| Houston | $22.32 | $24.93 | $28.40 |
| Washington | $23.86 | $30.71 | $34.34 |
| Philadelphia | $24.09 | $32.62 | $36.99 |
| Miami | $20.50 | $24.57 | $27.85 |
| Atlanta | $22.03 | $24.84 | $28.25 |
| Phoenix | $22.72 | $28.74 | $34.55 |
Related Calculators
- Bathroom Remodel Cost Calculator — renovate an existing bathroom instead of adding one
- Kitchen Remodel Cost Calculator — estimate kitchen renovation costs
- Roofing Cost Calculator — your addition will need a roof too
- Foundation Repair Cost Calculator — fix existing foundation issues before building
- Concrete Calculator — calculate concrete for the addition's foundation slab
Estimates are for planning purposes only. Consult a qualified contractor for critical projects. Actual material requirements may vary based on site conditions, waste, and installation methods.
Pricing last verified: February 2026. Material prices vary by region, season, and supplier. Prices shown are national averages for planning purposes.