The new floors have now been laid. The floor slab is 150mm of dense concrete, which sits on top of a new layer of insulation which is 250mm thick. Around the side of the floor slab is 50mm of edge insulation.
The new floor slab will act as a heat store to help keep the house warm through winter, with heat loss from the slab to outside of the house minimised by the insulation below and around it. The heat then only has one way to go; back into the house as the air temperature drops below that of the floor.
In summer the floor slab will act in reverse as a cooling mechanism, because as the air temperature rises above that of the floor, the excess heat will be absorbed into the dense concrete.
The mass of the original solid walls will act as a heat sink in a similar way, helping to cool the house in summer and heat it in winter, once it is fully encased in insulation, which is the next major phase of the retrofit.
I wondered if you’ve modelled this to see what impact the concrete has, assuming of course the new tenants don’t put carpet over it which may nullify its effect. I’d guess that the impact is relatively small compared to that of the walls.
If a floor covering goes some way to nullifying the thermal release from the concrete floor, how can any tenant overcome this affect?
Hi Robert – we didn’t carpet the floors, we tiled them. Large rugs are fine (we have them at Hockerton) if tenants like a softer, warmer surface under their bare feet.