Context

A 4-bedroom, acoustically and thermally efficient house was being built as a complete system build by Revolution Homes. The client specified a masonry fabric shell along with the thermal mass benefits associated with it.

Work undertaken

The H+H Rå Build method of thin-joint aircrete construction was selected by Revolution Homes for the project due to its excellent thermal and acoustic properties. Rå Build also allowed a rapid construction of the inner weatherproof shell of the building; this enabled a faster build time whilst still maintaining the robustness of a masonry build.

Rå Build can create ground floors, exterior walls, upper floors and partitions as an inclusive package for a time-efficient, cost-effective solution, which competes effectively with timber-frame solutions.

Only H+H’s network of recommended contractors are used which maintains quality and ensures the speed benefits of the method are fully realised.

Outcome

The build resulted in a dwelling with high thermal performance and a B rating in the Energy Performance Certificate. Underfloor heating and an air source heat pump helped in achieving this figure.

Andrew Edwards, Partner, Revolution Homes: "For a self-builder who wants masonry, we only use thin-joint aircrete construction not traditional dense block-work with standard cement mortar. In this case the Rå Build method was ideal as it offered everything the client specified: a masonry solution with excellent thermal and acoustic properties and the same build time as timber-frame solutions. Rå Build has proved its worth time after time."

Build method

  • 100mm Standard Grade Celcon blocks for the entire house with a timber-cut roof and solid concrete foundation
  • Dry-lined and plastered interior walls
  • Celotex within the 100mm cavity wall
  • 100mm Celcon Blocks for beam and block floors

Product benefits

  • Provides a fast, watertight masonry shell to enable internal trades to start sooner
  • Meets or exceed Part L and Part E of the Building Regulations
  • Simplifies the construction process
  • 80% recycled material
  • A+ rating in BRE Green guide
  • Excellent thermal and acoustic properties
  • All components for the Rå Build method available off the shelf
  • Block-work is highly adaptable, allowing for any last minute design changes
  • Air permeability of 0.12m³/hr/m²
  • Celfix mortar can be stored within footprint of building - small quantities mixed as required
  • Class 0 rating for surface spread of flame

Applications

  • Internal and external leaf in cavity walls
  • Solid walls
  • Separating / party walls
  • Flanking walls
  • Partitions
  • Multi-storey
  • Foundations