glazing_u_valuenumberdefault: 1.80.4–6 (step 0.1)Thermal transmittance of the window assembly including frame. Single glazing: ~5.7; double: ~1.8–2.8; triple: ~0.5–1.0.
Replacing single glazing (5.7 W/m²K) with triple glazing (0.8 W/m²K) reduces window heat loss by 86% and eliminates cold-radiation discomfort near windows.
solar_heat_gain_coeffnumberdefault: 0.40.1–0.87 (step 0.05)Fraction of incident solar radiation admitted through the glazing. High SHGC (0.7+) maximises passive solar gain; low SHGC (0.2) minimises summer overheating.
In hot climates, reducing SHGC from 0.7 to 0.25 can cut cooling demand by 30–40%. In cold climates, high SHGC south-facing glazing can offset 10–20% of heating demand.
wall_u_valuenumberdefault: 0.350.1–2 (step 0.05)Thermal transmittance of the opaque wall assembly. Solid brick: ~2.0; cavity wall with insulation: ~0.3–0.5; passive house wall: ~0.1.
External wall insulation bringing U-value from 1.5 to 0.25 W/m²K typically reduces heating demand by 25–35% and is the most common deep-retrofit measure.
wwrnumberdefault: 0.30.1–0.9 (step 0.05)Fraction of the total facade area that is glazed. Regulatory limits typically 0.25–0.40 for energy compliance.
Increasing WWR from 0.3 to 0.6 can triple window heat loss in winter and double solar gain in summer. The optimal WWR depends on orientation, climate and SHGC.
shading_depth_mnumberdefault: 00–2 (step 0.1)Depth of horizontal shading device (overhang, balcony or brise-soleil) measured from the facade.
A 0.6 m overhang on a south-facing facade at mid-latitude blocks ~80% of summer solar gain while admitting low-angle winter sun. Deep overhangs (>1.0 m) can eliminate summer solar gain almost entirely.
Run with default settings to see a baseline facade performance map. Then test improvement scenarios: - Reduce glazing_u_value to 0.8 to model triple-glazing retrofit - Increase shading_depth_m to 0.6 to model added overhangs or balconies - Adjust wwr to find the optimal glazing ratio for your climate Buildings rated 'poor' (>1.5 W/m²K overall) are the highest priority for facade improvement. Compare heat loss tables before and after to quantify savings.