The chemical reaction that forms aircrete creates a structure where each block is made up of millions of non-interconnecting cells.  With its own air pockets trapped in the block, aircrete provides inherent thermal insulation as well as complete water resistance and effective sound insulation. 

Thermal insulation properties are further enhanced by the use of H+H’s Thin-Joint masonry, which, by reducing the thickness of the mortar joints from 10mm to 2mm and ensuring the joints are fully-filled, further increases the air-tightness of the wall structure.

Standard cavity-wall structures with a 100mm cavity filled with insulation and using either Celcon Blocks for the inner leaf, or Celcon Blocks in a solid wall construction with external wall insulation, can easily meet the thermal insulation requirements of Approved Document L of the Building Regulations. 

Celcon Blocks have been used in a number of Zero Carbon and Passivhaus certified buildings, demonstrating the potential for aircrete to be used in the most highly-performing energy efficient homes.

The most recent amendment to Part L, dated 2013, further reduced the allowable U-value for external walls and also emphasised a “fabric first” approach to energy efficiency and thermal performance for houses.  More detail on the revision and standard wall details for Celcon Blocks is available for download on this page.