Water company build over agreements

[sjmac]

I've searched high and low, so what actually qualifies as "building over"

Is a patio that happens to have a shed land on it a "build over". All the things I can find suggest only below ground counts, that said the property I'm viewing is easily with 3mtrs and searches suggest no build over agreement in place, Is this because it would have been agreed as part of the development and the main sewer connection?

 

[jono_h]

I’d be suprised if you needed a build over for a patio or shed - it’s unlikely to affect a sewer or lateral drain. Welsh Water specify a need for an extension, annexe, conservatory or garage.

If the Water Authority did need to access the pipework the cost to re-instate is minimal.