A blower door test being conducted at Jer Rynhart's super air-tight Wicklow home — the house has an air changes per hour rate of 0.11

By Gavin O Se, NSAI certified airtightness tester, certified passive house designer and BER assessor with Greenbuild

Recent issues of Construct Ireland have featured houses that have been to the very best international standards of airtightness: eg Jer Rynhart's house in Wicklow and Tim O'Donovan's house in Cork, both of which had just a fraction of an airchange under standardised test conditions.

At the same time as these super-airtight houses are being built, the latest draft Part L of the Building Regulations is proposing to lower the air permeability rate for new dwellings from its present level of 10 m³/(hr.m²) to 7 m³/(hr.m²).

I was quite disappointed ― though unsurprised ― to learn of the new maximum airtightness level. It set in process a train of thoughts, the result of which is this article, in which I will look at:

    •    Where are we in terms of airtightness and airtightness testing?
    •    Where are we going?
    •    Where do we stand internationally?

Built in 2004, Tomás O’Leary's house in Wicklow was the first in the country to be certified by the Passive House Institute — but how would it fare when subjected to a BER assessment six years later?