We want to build an en-suite adjacent to our first floor bathroom.
We have had conflicting advice on what we can do about drainage. In particular the length of runs to the existing stack.
Who do we go to for a definitive answer on what we can and can't do. We've looked at Part H of the building regs but it doesn't answer all our questions.
We have drawings of what we want. We just want to know if it's legal. And if not, what we need to do.
Many thanks in anticipation of some help!