Building façades: sustainability, maintenance and refurbishment

The UK has a fairly mature building stock with between 1 and 5% of new buildings being introduced each year. The development of new façade solutions that can respond to the needs of the occupants of both new and refurbished buildings is, therefore, a key area for development. The built environment is a major consumer of energy across the domestic, industrial and service sectors. The construction and operation of buildings are responsible for about one-third of the energy use and one-half of the electricity use in most industrialised countries. A large share of the energy use is associated with protection from the external climate and operation of systems necessary to give the occupants a comfortable indoor environment. Natural light is seen as a key driver to people's well-being both in the workplace and at home. To realise high daylight factors in offices on overcast days, however, in particular requires highly glazed façades. Single-glazed windows result in high winter-month heat loads, whereas modern double- or triple-glazed units could result in summer overheating without additional solar protection or ventilation. This paper discusses the issue of façade refurbishment or replacement in the UK for multioccupancy buildings in both the commercial and domestic sectors. Sustainability is considered from people, process and product perspectives for traditionally glazed façades in comparison with double-skin façades and climatic envelopes.