I got my kiln about 3 years ago and built it out of the foam that Sauno recommended. It didn't last too long in my workshop as it got dinged a lot and eventually after doing about 6 loads of beech, oak and yew, I felt it was leaking too much. The temperature wouldn't go up to the 70 degrees and it took about 8 weeks for the run. I am planning to build another one shortly and this time it will be narrower and taller so it takes up less of a footprint. As I don't like the sauno plans this time I will be using the Nyle kiln plans which I think will be better. I have a base built from cls and teak lab worktops which will be slightly modified. My kiln is near my workshop double doors which has a slope and I just drain it out there.
For the last 15 years or so I have been using a chainsaw mill and have good access to as much oak, beech, yew, sycamore, ash, poplar etc as well as having a van. I mainly use oak and beech in my business and as I have just forked out a grand on oak for a project (which if I had cut myself would have been chucked in the stove) it has spurred me on to replace the kiln.
One thing I did notice from your photos Togalosh is that you are not using ratchet straps to bind all your timber together to stop it looking like propellors. This is important and should not be under estimated. Even if I am filling the kiln to the gunnels with heavy slabs I always used them to keep it flat as possible. Stainless steel ones can be bought for about 30 quid a pair on Ebay or from marine chandlery stores.
Nyle also have a very neat way of sealing the kiln up with a gasket which I reckon is far superior to the way sauno recommend and I will be going with this method myself. I also recorded daily the temperature inside the kiln and the amount of leccy used in the workshop. This time I will get one of the meter things which measure the leccy usage so I can maybe workout costs per cubic foot.
Mike