Window Replacement in Kentfield, CA

Moisture, not energy, is the driver here

Kentfield's climate is cool and shaded under the mountain canopy, so the case for new windows is less about cutting a big cooling bill and more about stopping water and air infiltration at the perimeter. The fog that drains down the slope and the wind-driven drizzle off the mountain look for any gap in the flashing around an opening, and older units on these homes frequently show fogged seals and rot at the corner joinery precisely because the original detailing dumped water into the wall rather than out of it. Low-E glass still adds comfort by tempering the radiant chill of large mid-century window walls, but the largest gains come from correcting the flashing and air-sealing while the wall is open.

Mid-century glass walls and modern frames

Many Kentfield mid-century homes were designed around large fixed lites and sliding walls of glass meant to pull the wooded setting indoors, and the original aluminum frames in those openings are now a weak point. Aluminum conducts the slope chill and its seals have usually failed after decades of damp, fogging between the panes. We replace into the same generous proportions with thermally broken fiberglass or vinyl frames that hold up against the steady canopy damp far better than the old aluminum, keeping the home's open, light-filled character while ending the condensation and rot at the sills. On custom homes with clerestory bands and corner glass, we plan the unit sizes and mulls to preserve the original sight lines rather than defaulting to stock dimensions that would clutter the elevation.

Flashing openings into the drying plane

The reason to do windows with the re-side is that the opening can finally be flashed into the same drainage assembly the new cladding rides on. We set sill pans, back-dam the sill, and shingle-lap the head and jamb flashing into the weather-resistive barrier so any water that reaches the rough opening drains back out to the exterior instead of tracking into the framing. On the fog-shaded elevations that detail is the difference between a window that lasts and one that quietly rots the sill below it. Weep paths are kept clear so condensation off a cool slope morning drains rather than pooling. Done as part of the re-side, the opening becomes a drained, sealed part of a continuous wall rather than the gap the original builder left.

Windows on the mountain-edge parcels

On the Kentfield parcels that sit nearer the Mt. Tamalpais slope and its moderate fire exposure, the glazing earns a second consideration. Radiant heat and direct flame can crack ordinary single-pane glass, and a failed window gives a fire an open path into the framing, so for these slope-edge homes we spec dual-pane assemblies with at least one tempered lite and frames suited to the exposure. We also flag what sits below the sill — combustible trim, planter boxes, or stored wood under a window can undo the upgrade. Because moisture is the constant on these slopes, the fire detailing and the flashing have to be coordinated so the opening both drains and resists ember intrusion rather than the two goals working against each other.

Window Replacement for Kentfield homes

The full window replacement approach — materials, weather-resistive detailing, and the manufacturer standards we install to — is covered on the main service page, then specified for Kentfield's conditions on this one.

Full Window Replacement details →

Our Kentfield process