Green Building Store is now 21°

Passivhaus office for Swann Edwards Architecture

Swann Edwards Architecture has developed a newbuild Passivhaus certified 2 storey office,  with a floor area of 206.6m². The project draws inspiration from the agricultural buildings characteristic of its Fenland location and is Fenland’s first exemplar Passivhaus office project. The project joins less than a handful of certified Passivhaus offices in the UK.

21°’s PROGRESSION windows and doors were specified for the project and 21°’s MVHR Design Service also designed, supplied and commissioned the Novus 450 MVHR system for the project.

Windows & doors

21°s PROGRESSION windows and doors, with Uw value of 0.68 W/m2K, were chosen for the project.

We’d come across 21° products through contacts with Bill Butcher and Paul Smith. The insulated frame of the PROGRESSION windows worked well in the THERM calculations on the project and offered a better installation PSI value that those offered by alu-clad alternatives. We also liked the narrow sightlines and general performance of the windows. We’ve had no problems with the PROGRESSION windows and doors at all. They look really, really good. They’re helping make the office very comfortable and we’ve even experienced them frosting up on the outside! By early December, we still had not put the heating on in the office.

James Burton, Architect & Director at Swann Edwards Architecture


A PAUL Novus 450 MVHR system, designed, supplied and commissioned by 21°, was specified for the project. All ductwork for the system is exposed in the office and the MVHR unit itself is located next to the office reception.

We chose 21°’s MVHR Design Service for our offices as we wanted to have a quiet and efficient heat recovery system and we had already worked with 21° on another project. We also liked the spiral wound steel ductwork that 21° favours, both for its robustness and also appearance, especially as we are leaving the ductwork exposed in the offices.

James Burton, Architect & Director at Swann Edwards Architecture

It has been fantastic working with 21°. The company’s in-house Passivhaus Consultant Paul Smith has also helped us with our Therm calculations and the detailing of Compacfoam at door thresholds. We continue to specify 21°on every Passivhaus project we work on.

James Burton, Architect & Director at Swann Edwards Architecture

Project details
Life changing homes