How long does a home addition take in Chevy Chase?

A home addition in Chevy Chasetypically runs 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 additions projects across the DMV. That full span breaks into three phases: design and selections (usually 2 to 4 months),permitting and approval (1 to 3 months), and on-site construction (3 to 9 months depending on scope). The build itself is only one leg of the journey, and the earlier phases set the pace for everything that follows.

Where your project lands in that 6-to-16-month window depends on several factors specific to Chevy Chase. Scope and structural complexity matter most, a two-story addition with a new foundation and roof tie-in simply takes longer to design, permit, and build than a single-story bump-out. Montgomery County's standard permit review runs 15 to 20 business days, though expedited five-day review is available if schedule pressure warrants it. Homes within the Chevy Chase Village Historic District add another layer, since exterior work requires review by the Town's Board of Managers and compliance with Historic Preservation Commission guidelines, which can extend the approval timeline meaningfully. Older housing stock also has a way of revealing surprises, outdated wiring, undersized footings, or original framing that needs reinforcement, once walls open up. Finally, long-lead materials like custom cabinetry and specialty windows can add weeks if they aren't ordered well ahead of when the crew needs them on site.

MOSS's design-buildmodel is built specifically to compress that timeline. Because design, permitting, and construction all run through one team, we submit permit applications as soon as drawings are finalized rather than waiting for a handoff between firms. Long-lead materials get specified and ordered during the design phase, so cabinetry and windows are often ready to install the week the framing is complete. A single point of accountability also means that when Montgomery County asks for a revision or a subcontractor hits an unexpected condition in the field, the response is immediate, no finger-pointing, no scheduling gap while two separate firms coordinate.