How long does a home addition take in McLean?

Home additions in McLeantypically run 6 to 16 months from your first design conversation through move-in, with a median of around 11 months, figures drawn from 159 completed MOSS addition projects across the DMV region. That span covers three distinct phases: design and selections (where space planning, structural engineering, and material choices are finalized),permitting and approval (submission through Fairfax County and, where applicable, HOA architectural review), and construction itself. The on-site build is only one piece of that total timeline, and homeowners are often surprised by how much meaningful work happens before a shovel touches the ground.

Where your project lands in that 6-to-16-month range depends on several converging factors. Scope and structural complexity matter enormously, a straightforward bump-out addition moves faster than a full second-story addition requiring new foundation work, roof restructuring, and relocated mechanical systems. On the permitting side, Fairfax County's typical review window runs 5 to 10 business days for complete, well-prepared applications, but any back-and-forth with plan reviewers or HOA architectural boards adds time. McLean has a large share of properties governed by HOAs, and exterior changes, roofline alterations, new windows, changes to the footprint, often require advance board approval before permits can even be filed. Older housing stock introduces its own surprises: outdated wiring, undersized load-bearing members, or unexpected foundation conditions discovered once walls open up. Long-lead materials like custom cabinetry and specialty windows can add weeks if they aren't ordered well ahead of installation.

MOSS's design-buildmodel is structured specifically to compress that timeline wherever possible. Because our design, architecture, and construction teams work as a single integrated unit, decisions made in design flow directly into permit documents without the handoff delays common when separate firms are involved. We submit permit applications early, often while design details are still being refined, and we place orders for long-lead materials during the design phase so cabinetry and windows arrive on-site when the framing is ready for them, not weeks after. Our team's history working with Fairfax County reviewers means our documentation is prepared to anticipate their questions, reducing the likelihood of revision cycles that push your schedule back.