Replacement windows
We replace windows across the DMV, from single rooms to whole houses, and we choose glass for our climate: cold enough in winter and hot enough in summer that both numbers on the label matter.
How it works
An insert replacement fits a new window inside the existing frame. It's faster and keeps interior trim, and it works when the old frame is square and free of rot. A full-frame replacement removes everything down to the rough opening, so we can inspect, repair and flash the opening properly.
The DMV is IECC climate zone 4A. The 2021 IECC prescriptive U-factor for windows is 0.30, and ENERGY STAR uses 0.27 in Maryland. Low-E coatings and the right solar heat gain on south and west walls make a real difference in summer.
In homes built before 1978, removing old windows disturbs painted surfaces, so federal lead-safe work practices apply.
What we check on every install
- Frame conditionRot and water damage found and repaired before the new unit goes in.
- Flashing and sillSill pan or sloped sill and taped flashing on full-frame installs.
- Insulation gapLow-expansion foam between window and framing, not stuffed fiberglass.
- OperationSashes, cranks and locks work smoothly and seal.
- EgressBedroom windows meet egress requirements where they apply.
Questions we hear
Insert or full-frame replacement?
Insert if the frames are sound and square. Full-frame if there's rot, leaks, or you want more glass area.
Do I need a permit?
In Montgomery County, generally not when the opening and clear opening stay the same. Rockville and Gaithersburg have their own offices.
My window is fogged between the panes.
The seal on the insulated glass has failed. Often we can replace just the glass unit.
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