Plan to Remove Existing Fence Between 2 properties and Replace with Extension Wall, the Outside of which will be Flush with the Boundary

Question

I have recently obtained planning permission for a single storey extension to my property at the rear. I am unsure as to whether I need to serve a party wall notice on the adjoining owner. Basically I plan to remove the existing fence between the 2 properties and replace with the extension wall, the outside of which will be flush with the boundary. Ideally I would like access from the neighbouring property to carry out the works. Also am I allowed to run the gutter effectively into the neighbouring property as by fitting the gutter to the outside of the new wall it will technically be on the neighbours’ side.

Answer 

As the side wall to your new extension will be on the Line of Junction you will have to serve notice under Section 1 of the Act. Depending upon the depth of the excavation for the foundations you may also have to serve under Section 6. You can read more about the respective notices here.

You will not be allowed to run guttering along the new wall if it is on the boundary as that would encroach in to your neighbour’s airspace.