Hello...this is my first post.
I have a end terrace house which currently has a 3 meter rear extension...I have contacted the local authority and asked them if I would be able to extend it another 3 meters to make it a full 6 meter rear extension...the LA advised I could and this would fall into permitted development if carried out by March (or so) 2019.
What I would like to know is...is it possible to extend an existing extension without demolishing it and starting again? ...I just want to make the the rear extension longer...currently it has a flat roof and I would prefer to have either a pitched roof with skylights with a flat roof with lanterns.
...would it be the case of knocking down the rear wall/windows and just extending on from the current structure? ...any help would be appreciated so I can plan for the build and factor in the costs etc.
Property is in London.
Thank you.