Orientation changes solar gains and shading opportunities. Assess it alongside glazing, surroundings and occupancy.
Seasonal effects
Useful winter sun can become a summer load. Compare options in both seasons rather than considering heating alone.
South and west
Solar altitude and direction change how overhangs and external blinds work. West-facing glazing can receive gains when the building is already warm from the day.
Glazing area and properties
Orientation interacts with window area, transmittance and solar properties. More glazing also changes daylight, privacy and cost.
Trees and neighbours
Record obstacle height and position and seasonal canopy changes. Do not treat future planting as guaranteed shading without assessment.
Model rather than slogan
Compare options in PHPP or an appropriate model using consistent assumptions. A rule that all windows must face south ignores site constraints, views, layout and summer comfort.
| Item | Parameter | Check / result |
|---|---|---|
| Façade | Sun | Seasonal profile |
| Window | Area + solar properties | Specification |
| Shading | Controls | Realistic use |
What this means for your project
Compare several siting options before fixing the layout. Record shading, glazing area and the summer cooling strategy for each.
Sources and scope of review
Related reading
- How to Assess a Plot Before Buying for an Energy-Efficient Home
- Summer Overheating: Why Highly Insulated Homes Can Still Overheat
- Installing Windows in the Insulation Layer