Zero carbon: it can be done

the Offsite show was buzzing this year. Why? Because a clutch of low and zero carbon homes made their debut at the BRE Watford event, and one of them had even attained code level 6 – the standard expected of all new homes come 2016.

Minister for housing and planning Yvette Cooper opened the three-day event by praising the industry for its commitment to reducing carbon emissions. ‘You’ve shown how it can be done. Now we have to make sure that it is done,’ said Cooper.

Kingspan Offsite’s Lighthouse was the main draw. With its distinctive curved roof profile and open plan interior, its ‘funky’ design attracted as much attention as its code level 6 performance. Chris Twinn, director at Arup, was closely involved in creating the Lighthouse. ‘We have a lot of experience in designing energy efficient homes – in our team we had members who worked on BedZed for example – but to a degree this was new territory.’

Speaking at the show, Twinn explained that because they were dealing with something new, trades were turning up on site saying, ‘I didn’t know that was what I was fitting into!’ He added: ‘There’s plenty of scope for improvement regarding the pecking order of how things go together and how they are sequenced. And the construction costs will inevitably come down. When you do something the first time there’s an innovation cost over and above the build.’

No-one CM spoke to was able to reveal how much the Lighthouse cost to build. It was revealed, however, that the Lighthouse’s electricity bill was predicted to be £31 a year.

But Twinn said build cost was not the main issue, at least for the moment. ‘We’re looking at different typologies as well, not just detached family homes.’ In one respect, he said, the Lighthouse was the most difficult type of home to meet code level 6 because it’s a free standing heat loss envelope. ‘If we build blocks, for example, with several homes within, there are cheaper ways to generate electricity than sticking PV cells on the roof as we have done here. And building processes and logistics replicated on a large scale will bring other energy saving benefits.’

Twinn raised an intriguing point regarding the nature of our future homes. ‘We got far more involved in the internal fit-out than normal and it got me thinking: are we creating an intelligent building or a dumb box packed with intelligent gadgets? Most people are happy to upgrade their home entertainment systems from time to time but can you imagine homeowners ripping out their entire electrical system every five years?’ It certainly made Twinn think the future of zero-carbon homes should reduce their reliance on gadgets – such as smart metering and monitoring – which could be superseded within a few years.

Delegate Geoff Leigh, of English Partnerships, agreed: ‘The worry would be a normal household relying on and managing the installed technologies,’ he said. ‘But what I’ve seen so far is very impressive. It’s encouraging to see we can achieve code level 6 today – it’s a big step to making it achievable everywhere.’

Despite showing how it can be done, Kingspan has no plans to leapfrog the other code levels for level 6. Managing director Gilbert McCarthy told CM: ‘At the moment new public housing requires level 3 – and we have a number of solutions for that. It will be in the next five years that the main volume of new housing will be set at levels 5 and 6.’

It can be done, yes. But at the moment it just costs too much.