Ra Build Revolution

H+H’s innovative Rå Build method has been used for a private self-build project in Bottle Lane, Maidenhead. The property stands on the site of the old house, which was demolished in favour of a masonry build.

The client wanted to use masonry and aircrete in particular, as it enables energy efficient homes to be built without resorting to lots of renewables, in fact a good performance was achieved with under floor heating and the use of an air source heat pump to give efficient running costs for the house.

The client wanted a solid robust form of construction that allowed beam and block floors at ground and first floor and block partition walls throughout, thus a solid long lasting structure and one that could be approved by all insurance and financial sectors. The house had a final build cost of £350,000.

Andrew Edwards, Partner of Revolution Homes, said: “For a self-builder who wants masonry we only use Thin-Joint construction not traditional block-work. In this case Rå Build was ideal because it offered everything the client specified: a masonry solution, with excellent acoustic and thermal properties and the same build time as timber-frame solutions.”

Rå Build is an inclusive package which comprises aircrete blockwork and quick-setting Thin-Joint Celfix mortar. It creates the ground floors, exterior walls, upper floors and partitions, creating a weather-tight masonry shell, for a time-efficient, cost-effective solution.

The client was based overseas for the duration of the build and so Design and Build Contractors Revolution Homes wanted to offer them a comprehensive build package to ensure their peace of mind throughout the project and ensure the project came in on budget and build programme.

As part of the Rå Build, H+H worked with Revolution Homes to provide wall U -Value calculations, movement joint and BJR guidance as well as additional on-site Thin-Joint training.

At Bottle Lane, 100mm Standard Grade Jumbo Bloks were used throughout the build due to their all round performance and versatility. This eliminated any site confusion and reduced waste.

The original property had poor acoustic and thermal performance; Rå Build remedied this. The interior walls were constructed with 100mm Standard Grade Jumbo Bloks while the brick-skin external cavity walls were internally insulated. The resultant U-value came in on the ground floor at 0.20W/m2K and the upper floor at a much lower 0.18W/m²K. The four-bedroom, detached house was completed early in 2013.