Home Addition Cost in Maryland 2025: Complete Guide
Need more space but love your Maryland neighborhood? A home addition lets you expand without moving. Here's what you can expect to pay in Montgomery County and the DC metro area in 2025.
Home Addition Cost by Type
Bump-Out Addition
50-200 sq ft
$300-400/sq ft
Small extension to existing room
Room Addition
200-400 sq ft
$250-350/sq ft
New bedroom, office, or family room
Master Suite Addition
400-600 sq ft
$250-400/sq ft
Bedroom with bathroom and walk-in closet
Second Story Addition
800-1500 sq ft
$250-350/sq ft
Full or partial second floor
Sunroom
150-300 sq ft
$200-300/sq ft
Glass-enclosed living space
In-Law Suite
500-800 sq ft
$300-400/sq ft
Self-contained living quarters
Why Maryland Costs More
Home addition costs in Montgomery County, Bethesda, Rockville, and other DC suburbs tend to run 15-25% higher than national averages due to higher labor costs, stringent building codes, permit requirements, and quality expectations in this affluent market.
What's Included in These Costs?
- Architectural plans and engineering
- Permits and inspections
- Foundation work
- Framing, roofing, and siding
- Electrical, plumbing, and HVAC
- Insulation and drywall
- Flooring and trim
- Painting and finishes
ROI on Home Additions
In Maryland's competitive real estate market, home additions typically return 50-70% of their cost at resale. Master suites and family rooms tend to offer the best returns, while highly customized spaces may have lower ROI but provide significant lifestyle value.