The scheme by Kirkland Fraser Moor for this sensitive rural location in Essex is based on contemporary bespoke Passivhaus design with large basement for private client. Passivhaus or ‘Passive House’ is the fastest growing energy performance standard in the world, though relatively few have been built in the UK, according to NHBC figures as at July 2012, the number of Passivhaus buildings in the UK either completed or under construction stood at a relatively modest 165 compared with over 20,000 in Germany.

The Passivhaus standards strengths lie in the simplicity of its approach; build a house that has an excellent thermal performance, exceptional air-tightness and mechanical ventilation/heat recovery. The Knights Hill scheme for example utilises Insulated Concrete Formwork (ICF) and has a design air-tightness of 0.6 ach compared with current building regulations that allow a leaky by comparison 10 ach.