The ground floor is made from an intricate mesh of steel rods. Each one has been bent, transported and put in place, with thousands and thousands of wire loops. In this mesh are recesses and cut-outs for drainage, shower trays and the like, which all needed to be placed prior to the concrete being poured. The underfloor heating pipes are being laid at this stage too which is another factor to plan in. When you are working with a concrete base like this, there really is no room for error.
We also have to cast in angle brackets for the doors and full-length windows. These cantilever over the insulation so that the windows and doors are sitting completely in the insulation zone, while being supported by the concrete and steel base. The doors and windows weigh up to 500kg each, so these brackets have to be incredibly strong. While metal would have been the obvious choice for strength, this would have led to cold bridging, so we have used fibreglass to create a thermal break.