Yes, I'll get a quote from the architect or do you have a ballpark figure for what it all costs? (architect's services, structural engineering, etc.)
Aren't there any suppliers of stone garden houses where you can buy the whole planning package together? I only ever find that for wooden huts ;(
As far as I remember...
250 architect (friendship price)
250 structural engineer (he shouldn't really calculate, just generously put something together, I always build 5 times as solid as necessary anyway)
300 fees at the office and small stuff
100 wine to get the neighbors drunk for the signature
The costs are one thing, the annoying part was running around until the office etc. were finally happy and had all the required documents and data.
Well, I don't know of any suppliers of solid garden houses, it's probably too individual and too expensive for most. With wooden huts it's easier, you can pack everything you need on a pallet, and there isn't really much that can go wrong during assembly. But you can't expect a DIY craftsman to create a load-bearing base slab, solid walls, ring beam, etc. If you sell something like that, it can only cause trouble.