In a recent High Court case concerning the construction of a 5-storey house in an area of Cape Town with a 3-storey limit (presumably a loss of sea view was the problem), the Court remarked that you “are required to check actively for building plans every time any building work commences on a neighbour’s property.”   Delay may disentitle you not only from having the approval of the plans set aside, but also from stopping construction in the interim.

Having said that, if you are the owner who is building, think carefully about starting work if approval of your plans is in any way open to challenge - take advice on whether you should first get the written consent of all neighbours.  

The case in question shows the danger of proceeding regardless.  The plan approval followed the granting of departures from zoning regulations and relaxations of title deed restrictions and, although the neighbours only realised that there was a problem after a considerable amount of construction had already taken place (some R13.4m worth), the Court found that the neighbour had given plausible reasons for the delay in acting, and ordered a halt to all building work.  Worse, a demolition order is threatened if the plan approval is set aside.