Evaluation of a building's performance is still not a common part of construction and commissioning, the assumption being that a building will perform according to the design specification. Research has overwhelmingly shown that how a building is used is the critical factor, with up to 200% variation in energy consumption from identical buildings.

Sensor technologies in homes, providing data and insights into behaviour and building performance will be critical to the future of successful newbuild and retrofitting projects. A three-year project run by Coventry University with a social housing group has developed low-cost sensors which monitor temperature, humidity, CO2 levels and light, tracked against consumption of energy and water. This way landlords can find out whether excessive carbon emissions are caused by the behaviour of residents, problems with heating systems or the fabric of the building itself.

Sensors are to be tried in 150 properties owned by Orbit Heart of England. More than 200,000 items of data are generated from each sensor, crunched into a form that can be analysed by non-experts. On the basis of the 20 homes monitored and analysed so far, Orbit has been able to start making decisions on investment. For example, ground-source heating is often regarded as being energy efficient, but it needs to be permanently switched on. People more familiar with controlling the heat of a central heating system often switch the groundsource system off, which leads to a cold house with increased humidity and the potential for mould to form, resulting in unnecessary repair costs.

Having access to this type of information means that building managers and tenancy engineers can decide whether a refurbishment is needed or whether the tenant just needs more advice on how to manage the home more efficiently. Some properties will have a combination of issues that put them at risk of being below the threshold for healthy living. Sensor data allows Orbit to prioritise those that need refurbishments urgently and to highlight potential problems before they happen. The growing pressure of carbon-reduction targets aside, inefficient homes also tend to be unhealthy homes. Properly targeted retrofitting will also improve the living conditions and health of tenants.

Professor Elena Gaura is part of the Low Impact Building Centre and Director of the Cogent Computing Applied Research Centre at Coventry University. Her current research explores issues in the fields of microsensor integration and large-scale wireless sensor networks.