i have a inspection cover where i want the extension to go, ca this be moved?

Hi Kam it depends on who owns the drain you or wessex water. If its you you can lintel over the pipe, if its wessex water you will need to contact them. If you need any more help contact me Mike Cleverley

This should have been all sorted at the planning stage, where in relation to the proposed extension will the manhole be, ? If it falls inside the extension you will need a double sealed manhole to finish level with f/f/l If its outside, you might have to reroute the drainage, ie manhole on each change of direction, if pipes are passing through foundations you will have to fit lintols. The footings will need to be deeper than invert levels, all these works will need to be checked with bco, so it is them that you need to contact.

Yes it can be redirected

building control at your local council office would need to be informed to meet regulations they would also advise you of your options as far as moving the inspection chamber.

your builder should be able to advise you.If he cant,get another builder