The sides of the observatory are built on a 2x2 inch carcass with shiplap exterior and 9mm spruce plywood lining. Polystyrene insulator will be put in between to provide good insulation.

Here it is going together. The small opening is for a double glazed unit to give some visibility - so I can see the kitchen and when my dinner is ready :)

A steel plate holds the threaded rod in the right places for the pier and will be lowered into the concrete and supported by the two pieces of wood shown.

Here is my helper again getting things ship-shape!

A cut down fire door was on special offer at the local builders and provides a good insulation and secure door into the warm area.

Polystyrene is used for insulation, and a 'parliament' hinge allows the door to open right back onto the side of the construction.