I'd build the frame out of 2".2", fill the gaps with kingspan/celotex, DPM stapled to the outside then shiplap. Recess the electrics somewhere you won't nail or screw through at a later stage. Clad the inside with ply or T&G panels if posh.
The shed market is so competitive if you look around it isn't that much cheaper to buy a half constructed shell that'll be a piece of piss to erect and probably last 20 years with a decent bitumen roof and the occasional lick of wood treatment.
I'd build the frame out of 2".2", fill the gaps with kingspan/celotex, DPM stapled to the outside then shiplap. Recess the electrics somewhere you won't nail or screw through at a later stage. Clad the inside with ply or T&G panels if posh.
The shed market is so competitive if you look around it isn't that much cheaper to buy a half constructed shell that'll be a piece of piss to erect and probably last 20 years with a decent bitumen roof and the occasional lick of wood treatment.