Hi, I’ve gone through this 3 times in the last two years with different Major Works.
I have it in writing that Camden’s policy is now to create an enormous estimate for every job they do, which is far in excess of any possible costs, and that way they can never be caught out by underestimating the final bill.
Apparently their legal advice is that there is no down side to abusing the consultation process in this way.
They work out these estimates based on ‘archetypes’ of properties. They don’t visit or look at plans. We received estimated bills for communal areas but there are none.
That said, get into the nitty gritty of any estimate with a real person at Camden as soon as possible. In my experience they will rip you off wherever they can.