The Harris Academy Sutton is the UK’s first Passivhaus secondary school and the largest Passivhaus school in the UK.

Designed by Architype, the structure is formed predominantly from cross-laminated-timber (CLT), together with glulam beams, with a partially submerged ground floor constructed from concrete.

The school accommodates up to 1,275 students aged 11-18. The design was carefully considered with extensive and local authority consultation to improve the local infrastructure, encouraging staff, pupils and parents to take sustainable routes to school.

Nature is at the heart of the materiality: all classroom spaces have exposed ceilings, with acoustic rafts below, and corridors feature exposed CLT. The CLT roofs reflect the natural harmony of the building, with non-toxic materials providing exemplary air quality and environmental credentials.

Where timber wasn’t used, Architype opted for a palette of similarly natural materials, including copper cladding on the sports hall exterior to reference the science-focused nature of the site.

The floor slabs were designed to bear only on the external walls, glulam structure and central spine CLT walls, made possible by large continuous CLT panels. This means that the school’s internal layout is flexible, with the option for internal walls to be added or taken away as requirements change over time.

The building was designed with circular economy in mind; the bolted connections to the glulam frame allow it to be dismantled and reused at the end of its life. The exposed timber structure makes the building more lightweight, helping to reduce the need for piled foundations, lowering the embodied carbon of the building.

Architype’s expertise in Passivhaus, alongside Willmott Dixons’ flexibility in construction has helped to deliver a very low-energy building, with optimum internal conditions which hope to save as much as 90% on its heating bills.

Each room is served with a very small domestic scale radiator and light sensors to help students and teachers know how to use the room’s minimal light and heating most efficiently. The school has achieved an exemplary air leakage score of 0.3ACH, and is in the process of gaining Passivhaus certification.