Andy Hales Ecological Architect & Consultant 

Andy worked on this Grain Architecture project from Stage 4 (Technical Design), through to contract Completion; including developing the Detail Drawings and information, Contract Administration, Passivhaus Design and thermal bridge modelling. The clients are completing the interior of the house themselves with volunteer help, and the house should be fully complete & Certified in 2026.

The project prioritised minimising embodied carbon and use of natural building materials throughout. The foundations, and services could not use natural materials, but embodied carbon was minimised with concrete free steel screw pile foundations supporting timber glulam ground beams, which hold up the suspended timber floor and timber wall panels. The floor and roof are constructed of timber i-joists installed on site and the walls were prefabricated twin timber stud panels. The wall panels, floor joists & rafters were all filled with blown cellulose (recycled newspaper) insulation, and the entire house was wrapped with a continuous layer of rigid woodfibre insulation. The entire inner surface of the thermal envelope was lined with airtight OSB, with all junctions and penetrations sealed with airtight tape.

The walls are rendered externally with lime render and the roofs are reclaimed natural slate. Inside of the airtight layer is a battened services cavity. The inner finishes are being completed by the clients with lath & plaster using clay plaster made from clay dug up on site. A PV solar array has been installed in the garden.