Draft PPS18: Renewable Energy
Annex 2 Passive Solar Design: Introduction
1. Passive Solar Design (PSD) has always been a feature of traditional vernacular architecture. A blend of intuition and experience ensured that domestic scale buildings captured maximum light and heat from the sun whilst being positioned in the landform to act as a buffer against the worst of the elements.
2. PSD is an environmentally benign approach to building design which allows significant lifetime savings in energy to be made without initial or running costs. As such it should be regarded as the most basic starting point onto which energy efficiency and active renewable energy measures should be added. PSD does not result in any environmental impacts but reduces those which will inevitably arise as the consequence of the occupation and use of a building for any particular purpose.
3. PSD needs to be considered at the design stage as it provides effectively a one-off opportunity to save energy during the lifetime of a building, generally at no cost. In modern housing up to 20–25% of heating and lighting energy can be saved by the application of PSD principles.
4. When PSD is applied in conjunction with other technologies as part of a low or zero energy approach, the resulting buildings can be novel or unusual and this can create interesting and varied layouts and townscape. In the case of offices or public buildings such as schools, features with a PSD function such as ventilation stacks and atria can be incorporated in ways that add interest and character.
5. However, it is very important to realise that PSD principles can be applied equally effectively in housing and commercial developments which have an entirely conventional appearance. For example, a vernacular farmhouse could provide a useful design checklist: orientation towards the south, main living room windows in the south façade with splayed side reveals to maximise light penetration, possibly a long north sloping roofline down to single storey rooms at the rear of the house accommodating the kitchen, larder and few small windows.