This involved carrying out an ‘Ice Box challenge’ to test how well Passivhaus buildings perform in hot weather. The video of the experiment is currently on YouTube.

The Ice Box experiment involved two sheds, one made to the Passivhaus standard and one mirroring the current building regulation standard. The ice, which originated in Glasgow, are at present used at NMITE (The New Model Institute for Technology and Engineering) in Hereford to support training, and were temporarily moved to Guy’s Lincolnshire home for the experiment. 

The sheds were each filled with 0.5 tons of ice and left for a week during August last year. Guy opened the boxes after seven days to see how much ice had not been melted. The Passivhaus shed had lost 30% of its ice, with an inside temperature of 5 degrees Celsius. However, the building regulation shed had lost 60% of its ice and contained an inside temperature of 11 degrees Celsius. 

Martin said: “This was an experiment to see - are we all going to melt in well-insulated houses? 

“Insulation works in both directions, it takes longer for the heat energy from the sun outside to penetrate all of this insulation to get to the ice. So, will a well-insulated house cook you in the summer? No it won’t, it’ll keep you cooler.”

Jon Bootland, chief executive of the Passivhaus Trust, said: “The experiment demonstrated that the Passivhaus shed is good at keeping warmth in a building in the winter months and keeping things cool in the summer months, in much the way a thermos flask works. 

“The ice boxes are a great visual way to help dispel the myth that Passivhaus buildings lead to overheating. The extra insulation and airtightness actually helped reduce the ice melting in the Passivhaus shed.”

Ben Shirley, assistant professor at NMITE, said: “The ice boxes, filmed as part of Guy Martin’s House Without Bills programme, highlight the role of practical demonstration in communicating the benefits of high-performance construction to a wider audience. 

“They show how NMITE and the Centre for Advanced Timber Technology work with partners to bring building performance to life.”

 Shirley added: “Together, we’re making high-performance construction more visible, understandable and achievable.”

The experiment was carried out due to a collaboration between the Passivhaus Trust, The New Model Institute for Technology and Engineering and Edinburgh Napier University with support from the UK Research and Innovation funded Centre for Net Zero High Density Buildings, Scotland Beyond Net Zero and Housing Construction and Infrastructure Skills Gateway — The Edinburgh and South East Scotland City Region Deal.