London Dock School

Cost-effective Passivhaus school facilities focused on minimising Whole Life Carbon

Walsh joined the London Dock School project at RIBA Stage 3 and was asked to conduct a value engineering exercise. In doing so, we found significant improvements could be made to the original proposals and reduced the embodied carbon of the build by 30%.

The Walsh designs included changing 300mm RC slabs to 225mm post-tensioned slabs and significantly reduced the overall weight of the structure which allowed for a reduction in the number of piles. This approach to minimising embodied carbon was extended into maximising cement replacements and we recommended that the project should become an early adopter of 56-day strength concrete.

Sports facilities have been delivered on this constrained site by placing them in a double basement. Open double-height spaces were created to house the Sports England-compliant Sports Hall and a Multi-Use Games Area (MUGA). This was achieved with 20m long steel trusses and plate girders. Given that these facilities are placed underneath classroom spaces in the superstructure above which would experience intense periods of student load movements, we conducted a detailed analysis of the vibration response of these long-spanning structures to prioritise user comfort whilst minimising steel weight and materials.

The school was designed by Passivhaus specialist architects – Architype – and worked closely with them to coordinate a design that provided an unbroken thermal envelope and allowed for simple airtight construction of the façade substrate.

The result is a sustainable modern secondary school that offers exceptional facilities whilst delivering the lowest possible Whole Life Carbon in line with the UK’s Net Zero ambitions.