For many years there has been a focus on increasing the thickness of wall and roof insulation in a bid to reduce CO2 emissions. By Dave Taylor
However, improving u-values to 0.15/0.25 W/ sq m.K for the wall and roof insulation (from 0.25/.35) provides only 5 per cent reduction in energy consumption, while improving air-tightness levels to 3 cu m/hr/sq m (from 10) provides a 17 per cent reduction in energy consumption.
In this context, the building envelope – by achieving high levels of air-tightness that contributes towards significantly improving the energy efficiency – makes a major contribution towards reducing energy usage and associated CO2 emissions. However, improved air tightness is achieved without significant changes to specification merely through attention to detail in the construction of the building – so the additional cost is minimal compared with other means of significantly reducing the CO2 emissions.
In light of ever-increasing energy costs these benefits stack up economically as well as environmentally. Indeed a recent McGraw-Hill study revealed that thermally efficient buildings command 3 per cent higher rental rates and an average increase of 7.5 per cent in building value. Alongside this, they deliver 3.5 per cent higher occupancy rates and ultimately improve return on investment by an average of 6.6 per cent.
Whether in context of a refurbishment or new build project, optimisation of the building envelope particularly with respect to air-tightness has a crucial role to play in aiding delivery of Government targets. Given the current economic climate a ‘back to basics’ mantra, focusing on the application of practical solutions and attention to detail during the construction phase is key to improving a buildings operational lifetime performance. And it is fundamental to supporting the move towards a low carbon economy.
Dave Taylor is business development manager, Corus Colors