What does an extension shell include?

Swasterix

BigBrother said:

Will this include internal doors, skirting boards, connecting the electrics include sockets and switches, connecting the water, connecting the central heating, radiators, connecting waste pipes to sewage, lighting?

You’ve asked your builder to build you a shell so I guess the clue is in the title, ie. an empty shell. 

I’ve just had an extension built to shell. Included in this was Groundworks/foundations, adjustments to drainage/sewerage, connection for soil stack brought to ground level, gully’s fitted, walls build, roof on, windows and door fitted, floor screeded. That’s it. A watertight shell with basically nothing else done. Everything else I’ve had to arrange / do myself including (but not limited to); electrics, plumbing, heating, building stud walls, plasterboard / plastering, bathrooms, kitchen, internal doors, flooring, etc. 

Pretty much none of what you have listed above would fall under my understanding of what building a shell would entail. I’m assuming you were expecting it to be done but didn’t clarify with your builder prior to work starting. Possibly an expensive mistake. I’d suggest you contact your builder, maybe apologise for the misunderstanding and clarify what was to be included in your original spec. 

Grenage

As others have said, without a written agreement it's a nightmare.  Personally, I would consider a shell to be the bare minimum.  Walls, windows, roof, all watertight.

No electrics, plaster, skirting, fittings, etc.

gzoom

Shell will mean at most first fix, so initial wiring and plumbing (but nothing connected), water tight but that's it.