How long does a home addition take in Washington Grove?

A home addition in Washington Grovetypically runs 6 to 16 months from your first design conversation to move-in day, with a median of about 11 months, figures drawn from 159 completed MOSS additions across the DMV. That full span breaks into three phases: design and selections (where plans are developed, materials chosen, and engineering resolved),permitting and approval (submission through Montgomery County and final permit issuance), and on-site construction. The build itself is only one portion of that total timeline, and homeowners are often surprised by how much of the schedule lives in the earlier phases.

Where your project lands within that 6-to-16-month window depends on several converging factors. Scope and structural complexity matter enormously, a two-story addition with a foundation extension and a relocated bearing wall takes meaningfully longer to design and build than a single-story bump-out. On the permitting side, Montgomery County's reviewprocessruns 20 to 30 days from complete submission to permit issuance under normal circumstances, but if the initial plans require revisions, each resubmission cycle adds another 7 to 10 business days. Washington Grove's historic character and National Register status can also shape exterior design decisions, which may require additional back-and-forth before plans are finalized. Add in lead times for custom cabinetry, windows, and specialty materials, often 8 to 14 weeks, along with the occasional discovery of older framing, aging mechanicals, or unexpected site conditions common in established neighborhoods, and the range becomes easy to understand.

MOSS's design-buildmodel is structured specifically to compress that timeline wherever possible. Because design, permitting, and construction all run through one integrated team, permit documents are submitted as early as the process allows, and long-lead materials are ordered while the county is still conducting its review. There is no hand-off delay between a design firm and a separate contractor, no gap where information gets lost or schedules drift. From first conversation through final walk-through, one team owns the entire schedule, and in a jurisdiction like Montgomery County, that continuity makes a real difference.