Thornwood Addition
A 1,800 sf second-floor addition to a 1960s ranch house — a primary suite, two bedrooms, and a flex office — delivered with zero visible seam between old and new.
The Challenge
The existing structure's roof framing was non-standard — 2x6 rafters on 24-inch centers with no ridge beam — and had to be largely replaced to bear the new floor load. The clients required the ground floor to remain fully livable during construction, with a single-day 'blackout window' for the roof opening.
Our Approach
We pre-fabricated the new second-floor structure in a series of LVL moment frames that could be craned and bolted in a single 14-hour day. The existing roof was removed and replaced in that same window. Exterior cladding on the addition matches the original horizontal board-and-batten profile, repainted as a single unit so the transition reads as intention rather than accident.
The Outcome
The 10-month schedule was met. The ground floor was unavailable for just 1 day (the roof day) and 4 weekends of interior rough-in. The addition appraised $340,000 above cost in the first post-completion valuation.
- addition
- residential
- design-build
- second story