The Monterey pines at Marlhill predate the building of the houses by many decades. The Montereys have been mature and roughly at their current height for some considerable time. Everyone who purchased their house would have had a survey done and would have known about the risk of these trees and their Tree Preservation orders. Their household insurance would also have taken note of the context.
The planning permission given by the City Council would also have been aware of the trees, their age and protection. Two of the properties backing onto Marlhill Copse are very recent, having been built as infil to the gardens of other houses. Here is the link for the planning application for 13A Maryland Close:
It contains:
Therefore The City Council were concerned that the trees should be preserved when planning permission was granted. The footings of the bungalow were completed some time ago but it seems that the bungalow wan't erected until ~ 2000. The present owner seems to have moved in around 2005 and would have known the context.
Above is taken from SOMAP (City Council's own map). The diversion of the path through Marlhill caused by the felled Monterey (must have been felled between 1976 and 2003 see photos) is clearly indicated. This tree was probably illegally felled when 14a was being built.