Very nice JC101, do you mind sharing the name of the company you got that from or more details on the construction methods?
It's an off the shelf office company in the UK, you can literally design it on their website, it's all modular.
The pic attached is when the base went down. It's a metal skin around insulation and that sits on a metal ring beam with a number of concrete pads dotted around underneath. My floor is 3 such panels and they have a labyrinth joint between them. The result is the office is off the ground, the front left corner is level with the paving but the back right is a couple of inches up as the paving sloped slightly for drainage. The walls go onto the wood you can see in the pic. I had to remove the block paving from under the footprint before they arrived.
The roof is the green bits in the pic, again metal with foam insulation inside. Overlapping joints this time for when they screw it all together. The walls are also pre-fab, standard is white melamine faced chipboard, kingspan foil backed insulation, moisture barrier then an air gap before the external wood cladding. I also had it plaster boarded and skimmed, for additional insulation and because I would go nuts looking at the melamine and it's joints, plus it's virtually impossible to repair or paint it in the future or make good screw holes and the like.
Not the cheapest around, and I did look at a few. I went to see their factory & showroom before placing the order and so far very pleased. 3 Days to build the thing itself, plus the plastering and final fix etc. I saved some money by painting it and sorting out the electrics down to it, just had a sparky hook it up and issue the required paperwork. I didn't take their floor and had Karndean put down, nicer on the feet and if damaged it's easy to replace a "plank" as required.
It's called "The Garden Office" but is actually a different company underneath, they sell various designs under different branded websites but make them all in the same factory.
http://www.thegardenoffice.co.ukAfter checking with the accountant, it went through my company, to recover the VAT. But I don't mind spending the money to get something I can stand being in for hours at a time.