Kitchen extension - unable to do drainage survey

Shariq8

Hi

We are looking to an extension to our kitchen out the back (it was previously an extension out the side before we bought the house). 

We understand that we need to do a drainage survey but that we don't have access to the manhole cover. It looks like the previous owner built over it when doing a side extension. 

Is it possible to forgo doing the drainage survey given this situation? Is there a major risk if we don't do the survey. 

Section62

Shariq8 said:

Hi

We are looking to an extension to our kitchen out the back (it was previously an extension out the side before we bought the house). 

We understand that we need to do a drainage survey but that we don't have access to the manhole cover. It looks like the previous owner built over it when doing a side extension. 

Is it possible to forgo doing the drainage survey given this situation? Is there a major risk if we don't do the survey. 

The major risk you already have is not being able to access the drain/sewer in case it gets blocked.  Is it public or private?

I wouldn't contemplate for a moment building over a drain/sewer that previous building work has already removed all access to.

If it is private drainage then you should get someone to excavate to find the pipe and install a (temporary) manhole to allow access for a proper survey. Then work out what changes are needed to the drainage to allow the building to be constructed and restore maintenance access to the pipe(s).

If it is a public sewer then you'll need to speak to the water company and ask them what approach they would be willing to accept.  Be aware that by doing so you may void any indemnity policy you have in relation to the previous extension.