The blocks around downtown Bellingham hold some of the oldest housing stock in Whatcom County. Walk the Lettered Streets or the edge of the York neighborhood and you will pass craftsman bungalows and foursquares built between 1900 and 1930, many still carrying their original single-pane wood sash windows. They have charm, but after a century of southwesterly storms rolling in off Bellingham Bay, most of them rattle, weep condensation all winter, and let the wind from Holly Street and the waterfront rail line straight into the living room.
Why Old Downtown Windows Fail Here
Bellingham's marine climate is gentle on people and hard on window frames. Persistent damp from October through May swells wood sashes until they stick, then summer dries them until the glazing putty cracks loose. Painted-shut counterweight windows stop venting moisture, and the interior side grows the black mildew line so many downtown owners know well. Single glazing also does almost nothing against sound, which matters when you live within earshot of the trains, the bars on State Street, or WWU game-day traffic climbing the hill.
Aluminum sliders installed during mid-century remodels are not much better. The frames conduct cold, so on a 38-degree Bellingham morning they sweat enough to pool water on the sill and stain the drywall below.