no devils in our corners

There are 25 150º corners in our two linked roundhouses and 8 at 90º - the entrance lobby and sunspace. At Heptonstall in West Yorkshire there is a superb octagonal Wesleyan chapel - built as such so the devil could not hide in the corners. Well we won't have devils in our house either thank you very much. Now the geometry of the concrete block does not lend itself to making a 150º corner. Each corner has to be exactly right in the radius from the centre point and each of the twelve sides has to be exactly the right length- 2329mm for the 4.5m radius roundhouse and 3106mm for the 6m radius. The SIPS kit will need to fit very precisely. Not sure what the tolerances on each facet are but I hope they are more than 6mm. We have now finished the first course of corners for the 4.5m and with a circumference of 27948mm we were about 13mm out - one section about 5mm and two at 4mm. In percentage terms this is 0.05% out. Placing the two blocks for each corner does take some time as the measurements are all checked several times. It is painstaking and a pain. Very slow. We have now done 18 150º corners and 4 at 90º so we are well on the way. The ground is like a sponge and water springs out of unlikely places so we have had to install extra drainage.

Oh, and the 300m long mains electrical cable was fitted by SSE a couple of weeks ago, and the shed has its consumer unit wired up ready to go though we have yet to be switched on. Our house electrics will be run from the shed so we have our meter fitted too. This is not a temporary supply.