To raise the dome we need a wall to support the turntable. I bolted the base ring down with 12x75mm concrete bolts. I used 6 of them and added 50x50 zinc washers. I then used 90x35 treaded pine for the studs. I used joist hangers to connect the studs to the base ring and screwed and glued them all with wood glue. As I had some 70x35 pine, I used that for the noggings and spaced the studs with a 550mm centre on the inside which ended up being 600mm centres on the outside. As it was such a small cutting job, I simply used the jigsaw to cut all the wood. I used wood glue on the bottom of the studs but used selllyís no more nails on the noggings and the ring due to its resistance to running and its ability to fill gaps . I used 75mm pine treaded screws to the noggings and the ring and 25mm pine treaded screws on the base of the studs. I left a space for the entry door to the left and a space for a hutch/pod to the right and used the 90x35mm wood to connect the frame.

Iím not confident this will be strong enough to resists a cyclone, so I added noggings top and bottom to the left and right bays around the door and did the same to the bay opposite these. I then secured a piece of structural ply to these areas. Itís now solid as a rock.

I skinned the wall with colour bonded steel for around $200. Once skinned, I filled the empty wall cavities with left over foam. My digital thermometer tells me the temperature inside the obs is the same as inside the house in the middle of summer.