The first energy-efficient product arrives

The extension is starting to grow, and thanks to careful arrangement of the various blocks, we should lose virtually no heat from the extension into the ground via the external walls.

The foundation and first 4 courses of blocks are standard (to get us up to the required height as the house is higher than the garden).

Above that we have a row of highly insulating Marmox Thermoblock (the ones with the stepped edge), and then normal insulating blocks above that.