Estimating additions and ADUs in Washington, DC
Prices for additions and ADUs in Washington, DC, how they compare with the national median and what to know when bidding here, for remodeling contractors.
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Room addition prices in Washington
Q4 2026 pricing. Ranges are rounded to the nearest $50, or $100 from $5,000 up.
1 story over a basement
$45,900 to $303,500
150 to 1,000 square feet
National median: $45,700 to $302,100.
2 story over a basement
$69,700 to $466,600
150 to 1,000 square feet
National median: $69,300 to $464,400.
How Washington compares
Across the work in the cost data, Washington prices run 1% above the national median.
More work in Washington
- Kitchen remodelsCabinets, countertops, appliances and finishes.
- Bathroom remodelsTile, fixtures, vanities and plumbing rough-ins.
- GaragesOne and two car garages, framed and sided.
- Decks and porchesFraming, decking, railings and stairs.
- PaintingInterior and exterior, by surface area and substrate.
- Electrical workService upgrades, rough-ins, fixtures and finish work.
- All of Washington, DCEvery category, against the national median.
- Additions and ADUs nationallyNational ranges, cost drivers and the estimate's structure.
Estimate additions and ADUs with Washington prices
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