Extension Involves Demolishing Garage that shares a Party Wall. What Protection do I owe my Neighbour?

Question

I own a 1930’s semi. My neighbour (who is not attached) removed the guttering from my garage so he could erect a garage. His roof rested on what I think was a party wall (my property had a garage, his didn’t, this happened before I bought my property, since then we had  a dispute when he raised the level of his flat roof.  In doing so his builder removed 5 rows of tiles from my roof and built in approx 18 inches into my property. I asked them to remove this which was done reluctantly and replaced with plastic guttering. (I asked them to do this as I wanted my property not to be joined to theirs as I was thinking of extending).

I have recently had an extension built asking my builder to carefully demolish my garage and outbuildings, the neighbours flat roof is attatched to a wooden batten running along the party wall. He wants me to make his roof watertight by continuing his flat roof over this batten or cover it with lead. Do I have to do this? We have not touched his property, and I think he is responsible for finishing off his own roof. He is threatining me with a party wall surveyor at my expense.

Answer

If by demolishing your garage you are exposing a party wall to the elements then you should serve notice on your neighbour under Section 2(2)(n) of the Act. You would be responsible for making sure that your neighbour’s property was weathertight following the demolition work.

If you are merely exposing an adjoining owner’s wall that was built against your wall then there is no requirement to serve notice and no duty to make good.