Positive living

Solcer House in Bridgend, Wales, is the UK’s first low-cost ‘energy positive’ house, capable of exporting more energy to the national grid than it uses. Designed and constructed as part of the Wales Low Carbon Research Institute’s Solcer (Smart Operation for a Low Carbon Energy Region) project, the house reduces energy demand and integrates renewable energy supply and energy storage.

The house was designed by Professor Phil Jones and his team based at the Welsh School of Architecture and was originally built as a prototype to meet the now scrapped Government targets for zero carbon housing. A fabric-first approach was utilised throughout the course of the project, evidenced by the photovoltaic panels which have been incorporated directly into the roof.

Efficiency in sight
For the window specification, the project team initially approached local fabricator, Vellacine, for a solution. “We were approached by the Welsh School of Architecture as they were aware we offered timber hybrid windows and doors, and we had done work for them in the past,” said Les Calder, architectural development manager at Vellacine.

While considering the spec, the Welsh School of Architecture had also been quoted an alternative price for a Rationel hybrid system, so Vellacine had to put forward the case for its services, as well the benefits of frames from its supplier Senior Architectural Systems, over those from Rationel.

“We tried to sway the decision on the fact that all the Rationel products would be made on the Continent and then shipped over to the UK, resulting in installation through sub-contracted companies,” said Calder. “The biggest selling point that I successfully used as leverage was that the project team could come at any stage and see the whole fabrication process. We were also the ones who took the systems from the workbench to the site and installed it, so it would be a huge benefit for them to have just one company in complete control of the whole fabrication process. As we work closely with Senior, they would also be on hand at any time to come to site and talk about the benefits of the system too, so it became a joined up process for them.”

Hybrid benefits
In all, eight windows – five in double configuration, three in single configuration – were installed on Solcer House. Senior’s timber/aluminium Hybrid composite frames were specified with low-emissivity Pilkington energiKare glazing. Made from 100% recyclable aluminium and a choice of responsibly sourced engineered spruce or oak, Senior’s Hybrid windows are designed to offer excellent thermal properties. In addition, the system can deliver U-values of “less than 1,” according to Andrew Cooper, national specification manager at Senior Architectural Systems.

It was an unusual specification for Vellacine as the company doesn’t traditionally fabricate window systems with Pilkington glass. “On this project, the Welsh School of Architecture had approached Pilkington before even coming to us – it was always going to be the Pilkington glass on the project, whether it was Rationel’s system or ours. Pilkington was also on the photovoltaic roof tiles, so there was a tie-in there too,” Calder explained.

Affordable living
One of the aims of the project was to deliver an energy efficient building at a relatively low cost. The three-bedroom house was constructed at a total cost of £125,000, only £25,000 more than a typical new build of a similar size. This played a part in the specification of a double glazed system, as opposed to a triple glazed one, Calder says. “They wanted to have something on this project they could hopefully replicate on a roll-out basis, so they didn’t want to construct the building to a specification that wasn’t achievable commercially.”

Impressively, the entirety of Solcer House was constructed in just 16 weeks. The project is on course to become an exemplar for low cost, low energy homes, and it is hoped that the house could be constructed on a wider scale, dispelling the perception that low-carbon homes are both costly and difficult to construct.