Downstairs cloakroom loo & basin-does it need a sub stack?

[Bodgitnscarper]

Hi everyone.

A self build extension query if you will, please.

I am planning a downstairs cloakroom. Is the following acceptable?

1) Run the soil pipe straight down to a chamber via a rest bend with an invert level of 450mm below ground level?

2) Use the type of soil branch 90 with the side boss connection for the basin?

The original (upstairs) toilet stack is to be connected to another chamber approx 6 metres downstream of this one.

Does the cloakroom need a stub stack with an AAV?

Many thanks

 

[Nige F]

2) And I would say yes to stub + aav

 

[dilalio]

Box it all in with a phantom and btw pan.