Extension over drainage

[swampydrill]

I am getting a plan together for an extension on the rear of my house which is a corner plot. I plan to extend outwards from the side of the house by 3ft and run a further 15ft across the back of the house. In the corner where i want to go outwards, i currently have the guttering downpipe, so under the ground i have a rainwater pipe. Directly in line with the downpipe, i have a rainwater manhole around 50ft down the garden so i am assuming the rainwater goes straight down the garden. How do they build an extension over this and can they ?

 

[^woody^]

Move the drain or move the wall

 

[theprinceofdarkness]

As you don't want to have a down pipe in your new kitchen it will need to be modified. Also your new roof will need some form of drainage, it would seem to be a good idea to pick up the old drain outside of your new build.
Frank