We are moving the kitchen into the dining room which means we need to relocate the route for waste water.
My concern is that the run from the kitchen sink will be between 5 and 6 meters and the external ground levels are only marginally lower than the internal floor levels so the pipe will exit the building below ground.
I have come to the conclusion from research that i need to run the waste with a 50mm pipe with an air admittance valve (is this correct?!) but i don't yet understand how i go about connecting it to below ground drainage? Do i:
a) connect below ground to one of the existing waste pipes from the downstairs bathroom
b) connect below ground to the SVP serving the upstairs toilet
c) run the 50mm pipe directly into the manhole by coring through the brick lining then repointing around the joint?
or are all acceptable?
I have attached an plan drawing of the scenario for context. The red pipe is the one i have to run and the blue pipes are all existing.
thanks in advance!