Air Tightness Makes All The Difference

Air Tightness Makes All The Difference

Thinking Buildings just achieved a building with an air tightness of 0.59. Why does this affect the energy efficiency of buildings?

We specialise in low energy design and are currently working on a number of projects with extremely high energy efficiency standards.

We are currently working with Trunk Low Energy Building (www.trunklowenergybuilding.co.uk) to deliver a new build house near Aylesbury and we were absolutely delighted when we received an air tightness result of 0.59 for the building shell. By Way of comparison, current Building Regulations require a minimum air tightness of 10! Combined with high levels of insulation, this will dramatically reduce energy demand, limiting draughts and massively improving thermal comfort for the homeowner.

However, this result did not happen by chance – the building must be designed and detailed so that it is buildable, with  junctions carefully thought through and suitable products specified. It also requires a huge commitment by the supply chain and builders, and careful management during the build process, to ensure that the principles are communicated to everyone involved. Air tightness is not about using a million tubes of mastic!

The Zero Carbon Hub explain how air tightness affects energy performance as follows:

Achieving a reasonable level of airtightness is important for the energy efficiency of dwellings and the comfort of occupants. The benefits of improved insulation levels and more energy efficient heating systems are lost if warm air can leak out of a building and cold air can leak in. A mandatory requirement for airtightness has been set by the Building Regulations (for England and Wales, and Northern Ireland) to ensure that reasonable standards are being achieved, and it is compulsory to subject samples of newly built dwellings to a pressure test in order to measure and confirm their airtightness on completion.”

If you want to find out more there are a couple of excellent guides available that set out the principles and reasons for achieving high levels of air tightness in our buildings and these are available using the following web links:

http://www.zerocarbonhub.org/sites/default/files/resources/reports/A_Practical_Guide_to_Building_Air_Tight_Dwellings_NF16.pdf

http://www.passivhaus.org.uk/filelibrary/Primers/Passivhaus-Airtightness-Guide.pdf

Please contact Thinking Buildings