When John and Jeanette Fenwick were looking to enjoy an early retirement in the north of Scotland, they didn’t initially plan on utilising a new style of housing.
“We’d sold up down south, we had the money in the bank, and we thought we’d be able to pick and choose property and have the money to pay for it,” John says, “but it quickly became evident that what we wanted wasn’t on the market. So at that point we started looking at off-the-shelf kit houses. We located a plot – through an internet search, believe it or not – and then went down the self-build route.”
As part of their research, though, the couple attended the 2010 Scotland’s Housing Expo in Inverness, which featured a development of 52 competition-winning houses of different types and sizes, all with a focus on innovation and sustainability. One row of three terraced houses particularly caught their attention, as they had been designed to meet the German-originated Passivhaus standard.
At the heart of the Passivhaus concept, originated in the 1990s, is the design and construction of buildings so air tight that they don’t need a traditional heating system. Instead, they’re equipped with a Mechanical Ventilation Heat Recovery (MVHR) system which draws in clean cold air from outside, extracts warm dirty air from inside and loses just 5% of the heat energy in the process. As a result, a Passivhaus Standard home will require as much as 80% less energy to heat than a typical house.
At the expo, John and Jeanette were soon discussing their requirements with Ross A Barrett, an Associate at architects HLM in Glasgow. The company is largely known for large projects – such as the new Sick Kids Hospital in Edinburgh – but the three terraced house project had piqued their own interest in low energy design and best practice in Europe.
“Projects like this are really interesting because we learn a lot from them,” says Ross. “It’s really rewarding to work with clients like John and Jeanette, to craft something which is what they want and really responsive environmentally.”
With Ross’s help, John and Jeanette settled on building their new home on the site of a former croft in Gorstan, Ross-shire. Their new home, an L-shaped traditional-styled steading which they called Tigh-na-Croit, came together relatively quickly. “We had an idea of the style of house we wanted,” says John. “Basically Ross came up with an initial few sketches, and we developed it from there. The design process itself took seven or eight months, before we were ready to submit the plans.”
“They had an idea in their heads about the number of bedrooms, a nice big living space, dining, open plan, study and what-not,” Ross agrees. “So we then started to put together some ideas about how that would work, making sure that the living spaces all faced south to get the benefit of the sun, that the bedrooms faced east so they’d have a little bit of morning light. Also, there’s a fantastic landscape round about; so, for example, if you’re standing at the kitchen sink, there’s a slot window that gives you a nice view out the back, while in the living room there’s a little slot window that lets you see the hills when you’re sitting on the sofa.”
While the planning was relatively straightforward, construction was less so. “The site was fairly rough,” Ross admits. “There was a lot of rock below the surface, a lot of stone, so conditions underground were a little bit tricky. We had to rethink the drainage strategy and do it much earlier in the process; we had to lift the house slightly. The original idea was to put a ground sourced heat pump into the ground but there was just so much rock, we ended up going for an air-sourced heat pump.”
“There was a lot of landscaping work to do, a lot of rocks to come out,” John agrees. “It was quite an involved process turning what was, essentially, an ex-croft which had gone to wrack and ruin, into a nice place to live.” Nor does building a house to such exacting standards come cheap,, especially given the comparative lack of experience among building companies in that part of the world. “What we did do was still prefabricate the timber frame off-site, so that was dropped in probably in the space of a week or two,” says Ross. “Then we tried to sourced the outer skin – the timber, the render, the slate – locally as much as we possibly could.
“I think we’re we’re still trying to get our heads around what exactly the cost uplift is exactly,” he adds. “There’s quite a lot of research in Germany that says building a Passivhaus can be 10-15% more expensive. But, rather than spending around £1,000 a year on energy, depending on the size of the house, you’ll be spending less than £100 for heating. So there is that payback over time.”
“The concept is that the house is kept at a nice even temperature throughout,” says John. “We have a wood-burning stove fitted in the lounge and when that’s put on for the winter, the system does circulate the heat throughout the house; it’s comfortable throughout the house without having the blast of radiator heat and stuff like that.”
So does John think the time and money were worth it? “I think so, yes,” he says. “Like a lot of these newer concept houses there’s always a sort of pioneering aspect to it all, and there’s a certain amount of risk with them. There are only two of us living here, so there’s less heat generated; it’s quite noticeable when we’ve got a couple of guests staying over for a few days, the actual temperature of the house goes up as well. So this business of reusing every bit of heat that’s generated in the house is certainly valid!”
First published in The Scots Magazine, July 2016.
