Third of walls done

Probably finished about a third of the walls now. It's taking a long time - the rockery stone on the front is like a very heavy jigsaw puzzle... I'm trying to stagger as many joints as I can, and make sure that any stones that don't span the whole wall are capped with ones that do.

You can see I've added a triangle of concrete blocks in the middle for support. I plan to fill the gaps in these (and the triangular gap in the middle) with poured concrete, and insert bent rebar into them to tie these columns into the hearth slab. This should provide all the support the slab needs - leaving my outer walls only supporting a small fraction of the weight. The hearth slab will be reinforced as well - I feel sorry for anyone who tries to demolish this future...