Hello -

My house has a disproportionately large conservatory attached, built by
a previous owner, at least 10 years ago. It's a poor quality thing in
every respect. Most importantly, the foundations of the conservatory
have moved, so it now slopes by about 5cm over 3 metres. It is isolated
from the house by an external door, and has isolatable heating, so I
don't think building regulations are an issue.

I want to completely replace it with a smaller one, including the
foundations. I'm pretty sure (but not certain) some shared private
sewers run underneath it, but there were never any access chambers
underneath it.

All the companies I had round to quote say it won't be necessary to
inform the water company, because the conservatory was built before the
recent shift of responsibilty. They say planning permission is not an
issue because the new one will be smaller than the old one.

I might want to sell the house in a few years. Would I be wise to insist
the water company is involved? Any other advice?