Trees and neighbouring buildings change solar gains throughout the year. Include them in the site model before fixing the glazing design.
Obstacle geometry
Record obstacle positions, heights and distances relative to windows. One photograph cannot show seasonal shadow movement or low-sun effects.
Trees change
Deciduous and evergreen vegetation have different seasonal behaviour. Consider growth and uncertain maintenance; do not assign guaranteed transmittance without data.
Winter trade-off
Useful summer shade may reduce winter gains and daylight. Compare the annual scenario and room needs rather than only summer façade appearance.
Model and limitations
Initial analysis needs orientation and solar geometry; comfort also needs weather, internal gains and ventilation. Assess PV shading separately from window shading.
Common mistakes
Do not rely on a removable tree as the sole overheating measure. Consider future neighbouring development and controllable external shading.
| Item | Parameter | Check / result |
|---|---|---|
| Tree | Season and growth | Scenarios |
| Building | Height and distance | Geometry |
| Window | Orientation | Annual balance |
What this means for your project
Include obstacles in site inputs. Test a scenario without uncertain shade and provide controllable measures if comfort depends on it.
Sources and scope of review
Related reading
- Summer Overheating: Why Highly Insulated Homes Can Still Overheat
- Passive Cooling: Night Ventilation, Shading and Thermal Mass
- External Shading: Shutters, Louvres and Overhangs