Window replacement represents one of the highest-ROI improvements a Vermont homeowner can make, yet most specifications focus on the wrong performance metrics.
In a heating-dominated climate, the interplay between U-factor, solar heat gain coefficient, and air infiltration rate determines real-world energy performance far more than any single rating.
U-Factor and Vermont Winters
While U-factor measures conductive heat loss, Vermont's window performance depends equally on air infiltration. A window with an exceptional U-factor of 0.20 but poor air sealing can underperform a simpler unit with meticulous installation. We specify triple-glazed units with warm-edge spacers and foam-filled frames, then verify installation airtightness with blower-door-assisted pressure testing.
Solar Heat Gain Optimization
Passive solar gain through south-facing windows can offset a significant portion of Vermont heating load. Selecting glass packages with an SHGC of 0.40 or higher on southern elevations while using low-SHCG glazing on north faces requires careful modeling. Our fenestration designs balance daylighting, thermal performance, and UV protection to optimize whole-building energy performance.
