Windows & DoorsSince 2017
L-101 Montgomery County, MD

Doors, windows and remodeling in Montgomery County.

Our home county. From 1950s brick colonials in Silver Spring and Wheaton to new builds in Potomac and Clarksburg, we know the houses and the permit rules.

Elevation of a typical Montgomery County brick colonial showing entry door with sidelites, double-hung windows and a rear sliding door
A typical Montgomery County brick colonial and where its doors and windows usually change.
Short answer

DDA Construction is based in Montgomery County, Maryland, and installs, repairs and maintains doors and windows there, including pivot, lift-and-slide, multi-slide and bi-fold doors and imported systems, plus general remodeling and painting. It works across Silver Spring, Wheaton, Bethesda, Chevy Chase, Rockville, Potomac, Gaithersburg, Germantown, Olney, Kensington, Takoma Park and Clarksburg.

Key facts
Home baseMontgomery County, Maryland
Permit officeDepartment of Permitting Services (DPS); Rockville and Gaithersburg issue their own
Same-size replacementGenerally no building permit
Contractor licenseMHIC required for home improvement work
Climate zoneIECC 4A

The houses we work on

Much of the county's housing is brick and frame colonials, split-levels and ramblers from the 1940s through the 1970s, with newer custom homes in Potomac, Bethesda and the upcounty. Older homes usually need replacement windows, better entry doors and a real sliding or French door to the yard. Newer custom homes bring the large pivot, lift-and-slide and multi-slide systems.

Permits and rules in the county

  • DPS lists window and door replacement that doesn't change the opening size or net clear opening as work that generally needs no building permit.
  • Enlarging an opening, adding a new one, and interior alterations need a permit.
  • Rockville and Gaithersburg run their own permit offices.
  • Parts of Bethesda, Chevy Chase, Kensington, Takoma Park and other areas are in historic districts, which add review for exterior changes.
  • HOA covenants are separate from county rules.
  • Homes built before 1978 fall under the EPA's lead-safe RRP rule for work that disturbs paint, and window replacement is always covered.

What we do here

Specialty doors and windows, replacement windows, repair and maintenance, window-to-door conversions, remodeling and painting.

Towns and neighborhoods we serve

  • Silver Spring
  • Wheaton
  • Bethesda
  • Chevy Chase
  • Rockville
  • Potomac
  • Gaithersburg
  • Germantown
  • Olney
  • Kensington
  • Takoma Park
  • Clarksburg
  • Burtonsville
  • Aspen Hill

Questions

Do I need a permit to replace windows in Montgomery County?

Not if the opening size and net clear opening stay the same. Changing the size needs a DPS permit, or a city permit in Rockville or Gaithersburg.

Do you work in Rockville and Gaithersburg?

Yes. Those cities issue their own building permits, which we account for in planning.

Is my Chevy Chase or Takoma Park home in a historic district?

Parts of both are. Exterior changes in a historic district add review, so check the address before choosing products.

Sources

  1. Montgomery County DPS: Home improvements, permit or no permit
  2. Maryland Home Improvement Commission (MHIC)
  3. US EPA: Renovation, Repair and Painting (RRP) Program for contractors

Written and reviewed by DDA Construction · Updated September 2026

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