What is the cost per square foot for a home addition?

Cost per sq ft usually $150–$400+. Simple sunrooms run lower; full bath and kitchen tie-ins run higher. Foundation and finishes drive the total.

How long does a home addition take?

Small addition (200–400 sq ft) often 2–4 months. Larger or permitted work can take 4–8 months. Permits and weather affect timeline.

Do I need a permit for a home addition?

Yes in almost all areas. Structural, electrical, and plumbing work require permits. Contractors typically pull and manage permits.

What is included in home addition cost?

Typically: design/permits, foundation, framing, roof, siding, windows, HVAC/electrical/plumbing as needed, insulation, drywall, flooring, paint.

Does a home addition add value?

Well-designed additions can add value; bedroom and bath usually have better ROI than oversized great rooms. Check local comps.

How do I get the best home addition quote?

Get 2–3 quotes. Provide plans or clear scope (size, type, finishes). Ask what is included and permit timeline.

What is the difference between an addition and a bump-out?

Bump-outs are small (e.g. 50–100 sq ft) and often cheaper per sq ft. Full additions need foundation and full MEP.

How much does a bedroom addition cost?

Bedroom addition typically $150–$250 per sq ft. A 200 sq ft bedroom often runs $35,000–$60,000+ depending on bath and location.

How much does a bathroom addition cost?

Bathroom addition often $250–$400+ per sq ft due to plumbing. Small full bath can run $25,000–$50,000+.

Can I add a second story instead of an addition?

Second-story addition is possible if structure allows; cost varies. Often $200–$350+ per sq ft. Engineer assessment required.

What affects home addition cost the most?

Size, type (bath/kitchen vs simple room), foundation type, finish level, and local labor and material costs.

How much does a sunroom addition cost?

Sunroom or screened addition typically $120–$200 per sq ft. Three-season is cheaper than full HVAC four-season.

Is a home addition worth it?

Worth it if you need space and prefer staying over moving. Compare cost to moving and to local resale value of added sq ft.

How much does a 400 sq ft addition cost?

400 sq ft addition often $60,000–$160,000+ depending on type and location. Use the calculator for a tailored estimate.

Home Addition Cost Calculator

Use this free home addition cost calculator to estimate cost by size (sq ft), type (bedroom, bathroom, family room, sunroom, office), and location. Most additions run $150–$400+ per sq ft. Get a low, average, and high estimate below.

How much does a home addition cost?

Home additions in the U.S. typically cost $150–$400+ per sq ft depending on type. Bedroom and family room run $150–$300; bathroom/master suite $250–$400+. Get 2–3 local quotes.

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Important Disclaimer:

These estimates are based on current market data and average costs. Actual costs may vary depending on your location, specific materials chosen, contractor rates, and project complexity. We recommend getting multiple quotes from local contractors for the most accurate pricing.

Average Home Addition Cost

National averages run $150–$400+ per sq ft. Final cost depends on type and scope.

Cost by type (per sq ft)

Typical ranges

Type	Estimated cost
Bedroom	$150–$250
Bathroom / master	$250–$400+
Family room	$180–$300
Sunroom	$120–$200

Cost factors

What drives the total

Factor	Impact
Foundation	Slab vs full basement
Plumbing / HVAC	Bath/kitchen add cost

What Affects Home Addition Cost?

Size — Larger additions may have slightly better per-sq-ft rates; small bump-outs can cost more per sq ft.
Type / scope — Bathroom and kitchen tie-ins cost more than a simple bedroom or sunroom.
Location — Labor and material costs vary by region.

Data from contractor quotes

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Disclaimer: Estimates are for planning only. Actual costs depend on design, permits, and local rates. Get 2–3 written quotes.