Large project

[simonzebu]

Hi All, I am planning a major makeover of the back half of a 1920's terraced house. Currently the only plumbing is a back boiler behind a gas fire in the main room, kitchen in a single storey extension, and a first floor bathroom the soil pipe of which drops down the outside back wall in the corner formed by the kitchen extension. There is a manhole in the terrace outside the main room and another beyond the end wall of the kitchen extension.
I want to demolish the kitchen extension, build a new glass room over the existing terrace and kitchen footprint, put a new kitchen in the main room and build a shower room and wc between the new main room and the other reception at the front of the house. Ideally the entire new area will have underfloor heating.
The first question is: with so much new and moved plumbing, not to mention ripping up suspended floor and replacing with solid, are there any constraints on what can be positioned where, or can one do pretty much anything given the amount of digging and installation of pipes and electrics?
The second question is: what can I do about the existing soil from the bathroom, which, in its current position would drop down in the middle of a large open-plan room?

 

[Softus]

You can do pretty much everything (in the context of your questions).

Clearly the drainage system needs to be redesigned, but in principle there's no problem achieving what you want to do.

Wherever you place the new stack, it needs to feed into either the existing drain under the existing manhole or a new drain in a new manhole - the two drains would be connected if that is appropriate, or, alternatively, the old one made obsolete.

Secondly, if the existing manhole remains in service, you'll need to fit a double-seal frame & cover and leave access to lift the lid in the event of a blockage.

Please bear in mind that, as well you (or the builder on your behalf) being required to obtain LABC approval for all of the structural building work that you're planning, drainage alterations are also controlled by the BCO.