Connecting to existing foul drainage.

[ambuild]

I am building a new upatairs bathroom and want to connect the new s.v.p. to the existing open foul drain gully that takes the bath and sink waste from the downstairs bathroom.
I have exposed the gully and dont know how to proceed!!!
Any advice or links etc. would be much appreciated

[ambuild]

That is true for new houses but this one was built in 1924.
Older houses tend to have sealed waste from the toilet but open gullies into a trap for bath and sink.

[buildersmate]

True but if you extend a property (or modify it) then the Building Regulations that apply are those in current force. This is certainly true of electrical work, but some changes like replacing a heating boiler or thermal insulation one must not make the current position any worse than it is at present.
I'm not 100% sure on this one, but suspect you cannot run grey water into an exposed gulley like this. Since you need a Building Control application anyway for this work (because it forms part of Part H Building Control Regs) I suspect you ring Building Control at your local counmcil for verbal advice. They don't bite.