Vent pipe removal & building regs

[ed110220]

Hi all, I'm looking for some advice on vent pipe removal. I have a boxed-in vent pipe above the soil stack in my bathroom. Due to the room being small it would make the layout much more convenient if it was removed and replaced with an air inlet valve, as the neighbours have done (identical house).

However I have had conflicting opinions on this. Some have said this breaks building regulations if there is not an open vent elsewhere (there is not) and the air inlet valve is below the basin outlet level. Others have said that is nonsense and it's fine. Others have said it might break building regulations, but they would do it anyway.

 

[RickMoore]

The head of the drain should be open to atmosphere, if you only have one stack thats the head of the drain. Any aav should be fitted above the spillover level of the highest appliance served by the stack.