More room. Same home — but better.

Home Additions in the DC Metro Area

When you love your location but need more space, an addition can be the right answer. We’ve built everything from bump-outs and primary-suite additions to full second-story add-ons and detached structures.

Additions live and die on the architectural plan. Cornerstone works with experienced residential architects across the DC Metro area (including longtime partners like Studio: CrowleyHall) so your addition feels like part of the original home, not an afterthought.

Additions vary widely by project — most projects land between $250,000 and $1,000,000+ depending on square footage, structural complexity, foundation work, roofline match, and finishes. Contact us for a tailored estimate.