Hangar Decarbonisation, Cranfield University

R G Carter has refurbished and decarbonised two former ‘Type C’ wartime RAF hangars so that they could continue to service the University for many more years to come, while driving towards net zero carbon emissions by 2030. Now that the refurbishments to both hangars are complete (as of March 2024, with Building 84 completed in September 2023) the heating demand of the building has been reduced by 75%and moving from gas to a district heating system has resulted in 90% reduction in carbon footprint (potentially more as the district heating system continues to decarbonise), significantly reducing the operational carbon emissions. As part of the scope, the external appearance was of historical importance and therefore the innovative box within a box solution was created.

Whilst the building’s design provided a reduction in carbon emissions, the design also provided a significant cost saving in material cost, due to reducing internal footprint opposed to the traditional overclad solution. This added significant value to the University as it allowed the cost saved to be put towards funding towards much needed research which the University undertakes.

Demonstrated through assessment of the new building fabric and energy usage calculations, the design created a slightly smaller workable area which reduced the volume of energy consumption within the building. This was identified early on with our consultant partners who undertook a full design evaluation of the scheme to provide overall certification which led to the project exceeding the required air test value of 3.0 by achieving 2.2 upon completion.

We also had to meet Approved Document L standards for Building Regulations compliance. As part of this, carbon emissions for a ‘Be Lean’ building were taken from the modelling software in relation to U-values, ‘Be Clean’ building values were measured understanding the hangars were serviced via the University district heating system powered by ground source heat pumps and ‘Be Green’ renewable technologies (solar panels). All providing a betterment to the building regulations baseline.

Our design also provided further benefits to the operational carbon output and thermal efficiencies through installation of new hangar doors and improved plant. The technology linked and installed to the hangar doors meant that each time the doors were opened the heating would be stopped to reduce waste and to improve its energy consumption and thermal performance. This technology provided an operational cost saving.