Naturally ventilating UK non-domestic buildings: status and future policy

Increased concern over the adverse environmental impact of energy use has encouraged the design and construction of energy efficient buildings, and many are suited to natural ventilation. In the temperate UK climate, naturally ventilated buildings can provide year round comfort, with good user control, at minimum capital cost and with negligible maintenance. The principle of good ventilation design is to 'build tight - ventilate right'. That is, to minimise uncontrolled (and, usually unwanted) infiltration by making the building envelope airtight, while providing adequate 'fresh' air ventilation in a controlled manner. It is necessary to emphasise that a building cannot be 'too tight' - but it can be underventilated. This paper shows that there is considerable scope for making UK buildings tighter and indicates the level of benefits that will accrue. UK activity in this area is identified, including proposed statutory control ip the form of revised Building Regulations for England and Wales, which will address issues of tightness for the first time. Information is available on ventilation requirements necessary to satisfy safety and health criteria. However, criteria relating to comfort, especially those associated with odour, metabolic C02, and summer overheating are still being investigated. This paper sets out current thinking in this area, including policies relating to minimising effects of tobacco smoking in public and commercial buildings. The paper concludes by identifying currently available UK design guidance on natural ventilation. Various instruments which are underpinning these changes, such as revisions to the Building Regulations for England and Wales, codes and standards, professional guidance and support for policy-interests are identified.