estimated building costs for Building Control application

Your BCO might let you have a shufti at their copy of a Spons pricing/ estimating book.

Owain

Nope, but there is a Sarah Beeny book called Price the Job that does just what you describe - break a job down into elements and shows how to price each one.

However for this application, follow Jim's advice. IIRC the fees are banded anyway so its usually clear where about's you are going to land. As long as the estimate is arguable then chances are it will be fine.

thank you for help people. I'll get beeny and see what she has to say and also see how different it is from my guesstimate. As was remarked I only have to get it roughly right as the bands are very large.

Robert

Cambridge BC charge a fixed rate (100 quid) for renovation of a thermal element (up to 20K of work).

Are you sure your council don't do similar?

Indeed. When I had my garage converted into a kitchen (not DIY) I consulted a BCO before submitting a Building Notice, and he said "most garage conversion come in (specified, forget which) band. I plucked a figure out of the air, near the top of that band and paid the fee based on that figure. In the event, the actual cost was considerably more - but no-one questioned the original figure.

Our council currently charges a fixed price of ~£127-£130 (can't remember exactly) for the renovation of each thermal element.

When I did a reasonably large DIY building project a few years back I put in a costing which took it just into a low band - admittedly I was trying it on a bit - and I did get it questioned. So I recosted it to a random number into the next band, and that was that!

David