I am planning to put a single storey extension across the back and side of my 1930's semi.
the back wall will need the existing lintel above the patio door replaced with a longer one to make a larger opening into the extension. Does this work ever require the existing back wall to need underpinning?
the back wall will need the existing lintel above the patio door replaced with a longer one to make a larger opening into the extension. Does this work ever require the existing back wall to need underpinning?