In order the take advantage of the thermal mass of the existing solid concrete walls, and turn them into a heat store for the houses, we are building a new external wall and incorporating a large (250mm) cavity fully-filled with insulation between the two walls.  This significant layer of insulation will stop the heat absorbed by the existing solid walls transferring to the outside of the houses and being lost, as it does at present.

Before we build these new external walls, a couple of steps are required first:

1. Removal of the existing bays on the houses to make it easier to build a single wall right across the front
2. Addition of new foundations on which to build up the new walls

The video below shows the houses with the bays removed and the new foundations being laid.  The new foundations were combined with underpinning for the existing walls to make the overall structure more secure.

[youtube=http://www.youtube.com/watch?v=UjthbR13YcI]