I have a bungalow which had a loft conversion (bedroom) done some 20 years ago.
I'd like to add a little en-suite up there.
I am on a shared drains system with both pipes passing the back of the property at about 3 foot depth.
I don't have a soil stack or manhole.
Can I add a manhole or whatever and have a stack rising up the back wall of the property to hook a toilet and shower/sink into?
How do I go about it?
Are there specialists in this sort of thing?
- I'd like to get this part of the work done before we lay a new patio (obviously!)
Sorry about the twenty questions, but can anyone advise?

What he said. If you decide to DIY be aware that a special large radius bend should be used at the bottom of the stack not a normal 90 degree.