Our most airtight house?
An experienced timber framer with an eye for detail, Tim O’Donovan set about building a low energy stick-built home in the Cork countryside and achieved a staggering level of airtightness.
O’Donovan built his first timber frame house with his brother in 1995. Returning from a year of traveling with his family in 2004, he started talking with Toby Hatchett, now of low-energy timber frame company Greenhus.
“At the time he was a cabinet maker by trade, but he had this dream to build a low energy building,” O’Donovan says. The two built a timber frame workshop together, and O’Donovan’s interest grew from there.
“I got a lot of info from Toby on low energy building and set off on a mission to build the ideal building,” he says. “My inspiration came from the building techniques Toby was looking at.”
Work on O’Donovan’s house in Timoleague, Co Cork was nearing an end as Construct Ireland went to print. If O’Donovan was looking to create the ideal house, he’s certainly got it in one regard: airtightness. His house is phenomenally well sealed – it boasts an air changes per hour (ACH) figure of 0.11 (ACH) at 50 pascals, and an air permeability of 0.29 m3/h/m2 at the same pressure. The ACH figure is the best Construct Ireland can recall publishing, and looks all the more impressive when compared against the Passivehouse Institute’s famously tough standard – 0.6ACH.
For O’Donovan, the result is proof that stick-built can beat prefabricated timber frame for airtightness if the builder pays careful attention to detail. “Things can get torn in transport. I’ve seen frames come to site with membranes damaged,” he says of prefabricated systems. “As you build [on-site] you close and you seal, and you see every joint as the builder.”
But he says that regardless of the method of timber framing, care and attention yield good results. “There are some very good timber frame companies out there that pay a lot of attention to detail,” he says.