When engineer Andrew Brash and his wife were looking to build a forever retirement home in the Suffolk village that they love, Andrew was immediately attracted to the elegance of an Insulating Concrete Formwork (ICF) solution.
It was the thermal performance and simplicity that particularly appealed. He also liked the durability of ICF:
“If we were going to build a house with our name on it, we wanted something that was going to be around for a long time,” he says.
‘Mouses’ is a build of 330sq m on a 0.6-acre plot, which was completed in just 14 months, despite the large size of the building, reflecting the ease with which projects can be carried out using ICF.
The product selected was BEWI’s Thermomur® 350 Super, which is designed to provide an outstanding thermal performance (with a U-value of 0.15W/m²K), and has full NHBC and BBA approval, while also enabling a fast and efficient build. The cost/performance equation was viewed as a key benefit, which could provide the thermal performance necessary to gain a Passivehouse rating. The house also easily achieved its airtightness target. From a practical point of view, the ability to screw into the sides of the blocks and the way they all fit together also makes for a more straightforward build than with other systems, while generating less waste.
“We find the performance of the completed house to be absolutely fantastic,” says Andrew. “When combined with triple glazing, mechanical ventilation with heat recovery, solar panels and a heat pump, we estimate that our total electric costs each year for everything on this large house will be less than £200.”
The flexibility of the system meant that the team were able to deal with challenges as they arose on the job. Two recommendations which Andrew has, having completed his project, are to design any ICF self-build around the block dimensions as far as possible, to minimise cutting, and also to take maximum advantage of the training which is provided by BEWI for contractors without ICF experience who use the company’s Thermomur® system.