Builder Michael Bennett says that before he set out to build his first ever passive house in Rosslare nine years ago, he advertised it for sale as a passive house.
“I decided I’d put my neck on the line,” he says. “I was advertising something I didn’t have, and I knew that if I built it and I didn’t get my certification, I would be in the manure business in a huge way.”
It was a risky move, but Bennett was confident that by setting himself and his team an ambitious target, that they would all rise to the challenge. He called a meeting for both staff and subcontractors, where he explained what he wanted to do and why he wanted to do it.
“I told them, if this doesn’t work, I’ll be done for false advertising, but I’m going to make use of the right materials and I have what I hope are the best subcontractors around. Then I told them it’s down to them.”
That development – Grange Lough in Rosslare in Co. Wexford – became the country’s first commercial passive house development. Nine years on, Bennett continues to set ambitious challenges for himself and his team. Late last year, they broke ground on a new development – Madeira Oaks in Enniscorthy Co. Wexford. It features twelve semi-detached certified passive houses. Three of the houses have already been sold, with a price tag of just €170,000 each.
“I’ve had this idea for years that first time buyers should be able to afford passive houses,” says Bennett. “I just didn’t see any reason why they shouldn’t. We’ve put a lot of research into it over the last few years, and finally, last year, we were able to get started.”
All of the three bedroom semi-ds will be certified passive and will carry at least an A2 BER. In addition, each will be guaranteed under the Homebond Guarantee Scheme.
With a floor area of 102m2 (1,100 sq ft), the houses are of timber frame construction and each one incorporates the Nilan Compact P combined heating, cooling and MVHR unit. The design and build team estimates that total annual water and space heating costs will come in at under €200. However, a photo voltaic array on the roof of each house is expected to yield €200 worth of savings to electricity bills, making space and water heating cost neutral.
“Passive housing is down to two things,” says Bennett, “very good quality materials and top class workmanship. If you don’t have those, you won’t get certification.”
Madeira Oaks is also the product of nine years of experience and a great deal of research into ways of delivering a high spec at low cost. Shoalwater Construction provided the timber frames for the development, while design support came from MosArt in Wicklow.
Bennett explains that there was a great deal of behind-the-scenes work on PHPP, the passive house software package, in order to ensure that the range of building materials and techniques would comply fully with the standard, yet delver a design that wouldn’t break the bank.
“Before you turn a sod, you have to have all the work done, and that takes time. In standard houses with standard block walls, you get in, you get started and you make your changes as you go. With passive houses, you have to do your work beforehand. It’s all about planning. That is the secret of passive house. You have to be sure of where you’re going before you go the journey.”
Donal Mullins of Shoalwater Timberframe agrees. He always sets out to do as much construction work as possible in the factory before getting to site. Building and fitting materials in a factory setting goes a long towards ensuring quality and performance.
He points out too that the success of the Madeira Oaks experiment lies in the simplicity of the design. “We went through the design with Michael Bennett, low energy designer Seamus Mullins and MoSart. We stripped it out and kept everything as simple as possible. That was the name of the game.”
Michael Bennett also sets a lot of store by retaining the same team for every project. He’s seen very little turnover either among subcontractors or staff over the past ten years. Working with a well-trained, experienced, trustworthy team goes a long way towards ensuring onsite quality.
“Everything has to be carefully done, and it has to be 110 per cent. 100 per cent is not good enough. When people run into trouble getting passive houses right, most of the time, the problem is workmanship.”
Trust is also a big issue. If a tradesman accidentally punctures the air tightness membrane, everyone relies on him to hold up his hand and report the incident. Problems only arise if mistakes are covered up, making them that much harder to fix down the line.
The final plank in Bennett’s quality strategy is supervision. Willy Burke is his onsite supervisor, and is a constant fixture throughout the project. Burke keeps his own skills up to date with regular training courses. He also makes the point that working with experienced crews who understand passive house makes his job that much easier.
Communication is also central to his role. “We have a system of inhouse meetings with Shoalwater, and we have a full, written programme set out for the job, which details everything we have to do from start to finish. We all work off that programme”
Since innovation has been vital in developing the spec that’s being delivered at Madeira Oaks, it’s also important to keep an open mind as each house progresses, with an eye to any improvements that might be possible.
“By working through it,” says Burke, “you find out that if you shifted that there or this here, down the line that might help. Each house that we build shows us small changes we can make in the next house to make that even better.”
Bennett provides a manual with every house sold. In addition to comprehensive information on how to operate everything in the house, it also contains contact details for everyone involved in the build. He’s keen to point out however that he used to do the same thing when he built non-passive housing. Living in a passive house isn’t really any different to living in a conventional house.
“They’re a home, they’re for living in, they’re not different really to any other house other than you haven’t those expenses, and the way the fabric is built, it’s a warm house, it’s comfortable living…anyone who lives in one will tell you that.”
He says that the €170,000 price was chosen in part to get the development launched, and in part to prove a point – that affordable passive is possible. The remaining houses will be more expensive, but not much; he anticipates a selling price of €180,000.
“I’ve always said that passive houses are affordable for everyone,” says Bennett. “We’re building them as cheap as traditional houses. There’s no premium any more. That’s gone.”