Strategies for Non-ideal Sites/Design Performance Issues
Few buildings are located on perfect sites, with exactly the right amount of solar access, ideal breezes and natural ventilation and protection from all negative elements of the climate. Unfortunately, some people seem to think that if a building can’t be sited perfectly, there is no point attempting any kind of effective passive solar or energy efficient design. But this attitude fails to see that any passive design elements that can be used in a building will help to make a difference to the building’s thermal performance and improve its energy efficiency.
For example, just including appropriately sized eaves will control the amount of solar radiation that enters a home and therefore make it much more comfortable for its occupants. There is a range of design options available to improve a building’s thermal performance and each can have benefits in particular situations. The following table provides a short list of common design issues, and possible solutions which might offset the energy-efficiency disadvantages.
- Issue
- Potential solution
| Owner wants large windows with east/west view | Moveable shading, for example louvres, blinds, roller blinds or tracked shutters.
Best would be moveable louvred options, which don’t interfere with ventilation in hot conditions |
| Multi-unit building with double loaded corridor | Best to use east/west orientation and moveable shading, as described above.
Consider widening the plan form to allow increased distance between ventilation openings |
| Insufficient solar access in a building in a heating climate | Reduce mass levels, which will just increase the cost of the building for little benefit.
Increase insulation to all elements, for example: |
| North facing plan showing as under-heated | Reduce horizontal overhangs.
Increase window area |
| Building is overheating generally | Check that shading to north windows is adequate.
Consider reducing east/west window area, and/or adding additional vertical moveable or correctly angled louvre shading. Check insulation levels to all elements are adequate, particularly the roof. Review ventilation in the building, and consider increasing the size of openings or streamlining air pathways. Consider adding more thermal mass or better access to the existing mass, e.g. tiling slab on ground, or rendering rather than plasterboard to internal brick. If the above measures are not enough: Check the overall window area compared to the floor area to ensure that it is within the suggested limits. Check the overall wall area compared to plan area |
| Building is under-heating generally | see issues 3, 4 above plus:
Reduce mass levels and increase insulation, as described for issue 3 above. Increase window area and reduce horizontal overhangs, as described for issue 4 above. Add at least one properly shaded north window area. If the above measures are not enough: Check the overall window area compared to the floor area to ensure that it is within the suggested limits. Check the overall wall area compared to plan area |
