Looking for approx costs per sqm for a rear extension in the Greater London area. We would like to extend our lounge (shown in green) a bit further to the back and add a WC (shown in blue) as well in this rear extension. The extension will be around 7.5 sqm in total.
We plan to split this extended lounge in the middle with a stud wall to convert into an additional bedroom.
https://drive.google.com/file/d/1x5XF3XzQBEp9T48trEEf2l6eAt1yTDvm/view?usp=sharing