Suburbia’s green house

Somewhere on the road to Nottingham – and the university’s energy efficient C60 house – the scales fell from Alan Heywood’s eyes, leading the Stoneguard project manager to say: “I’d find it hard to revert back to using traditional methods and products considering what I’ve learned so far on this project. It’s a conscience thing.”

In reducing the carbon dioxide emissions of a typical family home by 60% (to meet the 2050 target set out in the 2003 Energy White Paper), Heywood and the team behind the C60 house want the entire industry to share his “conscience thing”. Once it is up and running, the performance of the house – designed by staff and students at the School of the Built Environment in a jointly-funded project with construction technologist Stoneguard – will be monitored over many years and, hopefully, the findings will influence future housebuilding.

Getting the spec right for external windows and doors is crucial, especially as the design has 50% of the wall surface glazed. In fact, external insulation (walls are 150mm EPS with a Sto render finish) and windows are the most important factor to get right in the drive to improve domestic energy efficiency. And while

it is easy to see the environmental benefits of a rainwater harvester or an earth-air heat exchanger system, the green benefits of other innovations are less obvious.

“Take these internal doorsets for example,” says Heywood. “With this set from NBS, it should take about 22 minutes to fit a door. That’s seriously quick.”

Pre-finished doors

Heywood says that on any project, door-hanging is a pain. “With house building, when you’re trying to get through as many as possible as quickly as possible when to hang the doors is always a tricky decision.” The advantage of the NBS doors, explains Heywood, is that there is no need for joinery on site. “I glue on my architrave and the doors come with all furniture attached. I don’t need a carpenter to start fitting locks or setting hinges with chisels and routers. It’s all pre-finished, meaning no joinery on site. It’s a massive saving on time, resources and labour.” Fewer people travelling to and from site and fewer power tools being used adds up to fewer carbon emissions.

Stoneguard’s search for the right glazing led it to Internorm, an Austrian company that claims to be the biggest window manufacturer in Europe, was brought into the fold. Expert at working with “passive houses” across the continent (a passive house goes even further than the C60 house by reducing carbon emissions by up to 90%) the firm was recommended to the Nottingham team by a passive housebuilder in Wales which had used Internorm’s Edition Passiv, a high-spec triple-glazed system.

UK representative, Thomas Fröhlich, was initially a little surprised at the project. “In Germany passive houses have existed for 25 years so when we got involved, I said, ‘It’s not really a house for 2050, because we can, and are, producing this kind of house now, in fact to even higher standards.” Nevertheless, Fröhlich accepts that the C60 project is as much about intent and good practice as it is about pushing the envelope. “In Britain the awareness of why it’s worth paying more for energy efficient products is not there. This project is at the forefront of changing perceptions.”

That change, thinks Fröhlich, will come from the consumer. “It will start with the private customer. Big housebuilders are not interested as long as they don’t have to be, they’re profit orientated. They’ll take the cheapest product and build it for the lowest cost. That’s how developers think. I should know, I used to be one in Germany.”

Heywood agrees and points out that energy performance statistics relating to domestic windows are starting to appear and reckons it won’t be long before people purchase houses on the basis of such statistics.

Thomas Fröhlich, Internorm

big housebuilders will take the cheapest product and build it for the lowest cost – that’s how they think

Commercial venture

For the C60 house, Fröhlich recommended Edition 4, Internorm’s triple-glazed wood and aluminium system. It knocks U-values down to around 0.7 W/M2K – half of what the Regs stipulate. It includes blinds between the first and second pane “so you don't need curtains”, suggests Fröhlich.

They were not supplied gratis, however, like many of the other products and services on the project. Fröhlich, smiling broadly, comments: “We said to Stoneguard you can’t get a Merc for free. But we’ll supply the products for manufacturing costs. The materials are really expensive and in Britain there is nothing comparable.”

A straight talker just like Fröhlich, Heywood states plainly: “If we could have found the same quality here we wouldn’t have gone to Austria for it. And anyway, it may sound mercenary but at the and of the day it’s a commercial venture for all those involved.”

Installing Internorm’s triple-glazed units requires specialist teams be brought in.

Air-tightness is essential, foil sheeting must be fitted, and the units themselves must be carefully handled (they are considerably heavier than other window types).

At the moment, only two teams in the UK are accredited to do such work, one in Scotland, the other in London. So at Nottingham, it’s likely an Austrian team will be used.

Internorm has also provided all of the elements for the sunroom, a double height space that will help control internal room temperatures. “We’ve designed the whole space. If the sun is too strong, the roller shutter goes down automatically,” explains Fröhlich.

Heywood has until the end of March next year to deliver the project. The steel frame has been built, and he has already built up to DPC level on site. Not bad considering he started the project just four months back.

And while his conversion to green building may be a “conscience thing” there are other factors that swung Heywood’s thinking towards new processes. From a site management point of view, he says, the green approach makes building easier, as many of the products and systems are manufactured offsite. Ultimately the customer will benefit too. “Until energy efficient housing is available on the mass market, the customer gets a raw deal on the biggest purchase they’ll ever make,” says Heywood.

However, if housebuilders are willing to learn from the C60 house, both industry and consumer, along with the environment, will be the major beneficiaries.