Home Addition Calculator
Estimate costs for expanding your home
Addition Details
Typical bedroom: 120-200 sq ft | Master suite: 300-500 sq ft
Include in Addition
Cost Estimate
Configure your addition and click Calculate
Estimated Total Cost
$0
$0/sq ft
Realistic Range
$0 - $0
Actual costs vary ±20-30%
Est. Timeline
8-12 weeks
Permit Cost
$500-1,500
Expected ROI at Resale
55-65%
Adds ~$0 to home value
Monthly Payment (if financed)
$0/mo
15-year HELOC at 8% APR
Common Home Addition Costs
Bedroom Addition
$20,000 - $75,000
120-200 sq ft typical
Basic room with closet, electrical, HVAC. No plumbing needed.
Master Suite
$50,000 - $150,000
300-500 sq ft typical
Bedroom + full bath + walk-in closet. Plumbing adds significant cost.
Bathroom Addition
$25,000 - $75,000
40-100 sq ft typical
Full bath with tub/shower. Plumbing-intensive = higher cost per sq ft.
Sunroom
$15,000 - $70,000
150-300 sq ft typical
3-season room is cheaper. 4-season with HVAC costs more.
Family Room
$30,000 - $100,000
200-400 sq ft typical
Open floor plan, vaulted ceilings, and fireplace add to cost.
Garage Addition
$25,000 - $65,000
400-600 sq ft (2-car)
Attached costs more than detached. Includes concrete, door, electrical.
Second Story
$100,000 - $350,000
500-1500 sq ft typical
Most expensive option. Requires structural reinforcement.
In-Law Suite / ADU
$60,000 - $150,000
400-800 sq ft typical
Self-contained unit with kitchen, bath, bedroom. Rental income potential.
Frequently Asked Questions
How much does a home addition cost per square foot?
Home additions typically cost $100-400 per square foot depending on complexity. Basic room additions run $100-200/sq ft, standard additions with plumbing $200-300/sq ft, and high-end or second-story additions $300-500/sq ft. Location significantly affects costs.
How much does it cost to add a bedroom?
A bedroom addition costs $20,000-75,000 on average. A basic 12x12 bedroom runs $20,000-35,000. Adding a closet and electrical brings it to $30,000-50,000. A master suite with bathroom can exceed $50,000-100,000 depending on finishes.
Is it cheaper to add on or build up?
Building out (ground-floor addition) is usually 10-20% cheaper than building up (second story). Second stories require structural reinforcement of existing walls and foundation, plus temporary relocation during construction. However, building up preserves yard space.
What is the ROI on a home addition?
Home additions typically recoup 50-70% of costs at resale. Master suite additions average 63% ROI, bathroom additions 54%, and sunrooms 49%. ROI varies by market - additions in high-demand areas with limited housing often see better returns.
Do I need a permit for a home addition?
Yes, virtually all home additions require building permits. You'll need permits for structural work, electrical, plumbing, and HVAC. Permit costs typically run $500-2,000 depending on project size. Working without permits can result in fines and problems selling.
How long does a home addition take?
Timeline varies by scope: Simple room additions take 6-10 weeks, additions with bathrooms 10-16 weeks, and second-story additions 4-8 months. Add 2-4 weeks for permits and planning. Weather delays are common for exterior work.
Should I add on or move to a bigger house?
Compare total costs: addition cost vs. (new home price + selling costs + moving costs - current home value). If you love your location and neighborhood, adding on often makes sense. If you'd need multiple additions, moving may be more practical.
No comments yet. Be the first to share your thoughts!