So here we are. With an ageing housing stock scattered across the landscape that urgently needs to be thermally upgraded. At least, if we want to meet our climate commitments and take seriously the energy crisis that is already taking its toll, having been driven to a head by the Russian regime.

Homes in the most deprived neighbourhoods really ought to be tackled first. The French call them ‘passoires thermiques’, energy sieves. But it is precisely the owners of these homes who lack the funds to invest in the necessary solar panels, heat pumps and insulation – despite all the well-intentioned support schemes. For the more affluent owner, the easiest solution remains external wall insulation: foam resin panels stuck and plugged onto the façade, which are then covered with fibreglass mesh and external plaster – known as ETICS (External Thermal Insulation Composite System) to those in the know.