Build over certificate - rear extension

[siva509]

All,

I am planning for rear extension in my garden (3m PD), Mine is 1925 built semi in South Birmingham area. I can see a drain in my drainage search(looks like surface water drain, i can see the Mains water and Foul water drain diagrams in the front of the property as per diagram).

Also I can see single storey extensions built by neighbours, one of the property is council owned (3M extensions). Severn Trent has two options (1.self certify build over if pipe dia is less than 150mm, 2. Formal application with CCTV drain survey before and after for certification). Any body has idea of the pipe diameter for surface water?

Also can I go for self certify option, since i can see the neighbours have built extensions?

[Conor]

I'd go digging and find it. Maps showed a combined sewer in our back garden right where we going to build our extension. A bit of walking around looking for manholes and a bit of digging proved that the sewer was 10m behind in the alleyway.

 

Re diameter... Anywhere from 100mm to 1000mm.....

[DevilDamo]

How do you know what approval process your neighbours went through? The self-certificate option is handy providing you can answer and meet all the requirements on the form. If there are any unknowns, you may find you’d have to formally apply for a Build Over Agreement... on the assumption the sewer is public.