Draft PPS18: Renewable Energy
Annex 2 Passive Solar Design: Information to Accompany a Planning Application
12. The following points should be used as a checklist when preparing a planning application.
Siting and Layout
13. The potential benefits of PSD can only be realised by careful siting and layout design. Sites should be planned to permit good solar orientation to as many dwellings as possible:
- the majority of residential access roads should predominantly run east-west with local distributors running north-south. This should allow one main elevation of the dwellings to face towards the south;
- houses should be carefully placed to limit the extent of overshadowing. Taller buildings should be placed to the north of the site with lower and low density buildings to the south of the site. Overshadowing resulting from landform, trees and buildings outside the site needs to be avoided as far as possible. Staggering dwellings or using stepped facades can also be of benefit;
- the majority of building facades should be set within 30 degrees of due south to enjoy the benefits of PSD; and
- the latitude band for Northern Ireland is mostly between 54o to 55o north.
Land form and landscaping
14. Working with the landform, landscaping should seek to act as a barrier to cold prevailing winds.
Design and fenestration
15. Given an appropriate site layout, the nature of rooms and window sizing will also influence the extent of passive solar benefit:
- in applying internal house layouts to the site, rooms which are occupied for much of the time (e.g. living rooms) should be positioned on the south side of the dwelling;
- generally windows on the north side of the dwelling should be smaller and fewer in number than those on the south; and
- garages and unheated conservatories can be used to provide thermal buffering on the north side of the dwelling but only if they are unheated.
16. The design should seek to make the best use of natural light by use of orientation and elements such as a shallow floor plan, atria and roof lighting.
17. The design should avoid using excessive glazing that will lead to overheating during the summer. Overhanging eaves and shading features can be used to limit solar gain during the summer. Natural stack effect ventilation driven by solar design should be used in preference to air conditioning.