fitting downstairs toilet

[roversfan]

If I want to fit a toilet under the stairs, are there any laws or regs that I could be breaking?

[Ethel]

Window or extractor fan comes immediately to mind.

You must have a hand basin too.

[buildersmate]

So does making a Building Control application to the local council - this inspects that the required fan is fitted (as above), the soil pipes are connected so the waste flushes away and the pipes are air-tight, thus avoiding smells.