My hut is a very simple design. It was built fairly quickly but is pretty sturdy. It is 27.5 sq m internally with a single pitched roof which is 2.5m at the highest point. It was built using fairly standard joinery materials (CLS and OSB) it has sarking boards for cladding,a tin roof with the toilet part of the main hut but accessed from outsde. The 4 windows are hardwood, double glazed opening. Very little in the way of 2nd hand or free materials, just a couple of doors and the rockwool insulation used for the walls. The hut was constructed at the farm steading before we got planning permission. To get it to that stage(base, walls, roof, window and doors) was about £8000 (the posh windows cost £400 for the wood, £200 for the glass and probably the same again to make and fit) Murray, the joiner, had estimated £250 per sqm so ot too far out( in fact spot on if you take away the windows!)

Taking it to bits again, transporting it to site and reconstructing was £1100. Not something that needs doing if you build on site.
Groundworks involved getting big granite boulders (20 I think) weighing at least 200kg each into place and level enough, attaching metal backets and joists. £1690. This was an alternative to holding the hut down with metal or wooden posts which, on this site, would be tricky because there's no depth to the soil. Other hutters with more favourable ground conditions got fencers to drive in posts with a post diver while they were doing fences.
The fence for my hut, required on these sites to keep livestock out, encloses about 200 sq m and has a 12 foot gate and was erected by professional fencers £1254.

The cost of the deck caught me by surprise. There is a bit front and back and it came to £2100, over half of which was labour as digging the post holes was a bit of a beast of a job. If Ihad known it was going to cost that much I would have done without just now and instead, spent the money on finishing off the insulation (floor and roof) and fitted a stove.
Gutters and downpipes are galvanised steel, £500. A single pitched roof without the little canopy over the front deck would have reduced that figure by about half.
The composting toilet cost £185
The interior work so far has just been putting up partitions insulating walls and clading withOSB which came to £1100. It's a very "no frills" interior

That adds up to £15924 but there was a bit more for the soak away and I owe my son, who runs the farm now, something for tractor and digger hire. So far he hasn't billed me (or the other hutters) Think he may have forotten! But I reckon about £17000 in total including labour and VAT on materials. Murray isnt VAT registered.
Murray the joiner is my ex partner and has a tendency to know better than me what I really want. For example, I asked him to build me something about 20 sq m and I ended up with nearly 30. I was going to source 2nd hand windows but he had already made them Apparently, the lad working for him needed the practice. To be fair I probably got some things for a bit less as this was the first hut and a bit of a trial run. He went on to build another 3 and put one of the kit huts together. He also bought a quad bike and a generator for the job which made things easier for everyone including the guys who came to fit stoves in some of the huts.
This is just one example but something similar on a smaller scale on a sheltered site without the need to keep out livestock, some second hand materials, particlarly windows, less decking. I reckon it wouldn't be so difficult to half the cost especiall if you can do some of the work. On the other hand, some of the other huts have stoves, solar pannels, lean to toilets, nice flooring, wood panneled walls, fitted kitchens full size gas cookers etc.
Here are the others

Another Murray build

A Tuin kit

A Murray build

A Murray

Another Tuin
Thank you for taking the time to do this Lee. It is a very useful piece of work.