Hi velosolex,
I'm afraid you may not have much of a case, if my reading of your distances is correct:
(11 + 13) = 24 metres between your existing house and the developers proposed houses
22 metres is the rule of thumb for directly opposing rear windows in mature residential areas.
Unless the trees are on your land the developer does not need your permission to cut them down.
However if he has undertaken to retain them as part of the formal planning process then he must do so.
It may well have been the undertaking to keep the trees that persuaded the Board of Appeal to grant the permission.
That is to say, the tress will preserve the privacy of the houses and in that context their continued good health is material to the development
In relation to the trees having a wall going through them, this doesn't seem to make sense - it must be to one side or another.
If it lies within a certain distance [a rule of thumb is within the crown spread] then building a conventional block wall with strip footing and piers wall may well kill or destabilize the trees.
Cutting through the root system on one side will probably do both.
In addition there may well be a protected zone required in the planning permission to protect the trees - say 1.5 M outside the crown spread.
At this point the developer may be required to erect a temporary fence to ensure that the trees are not damaged - this is incompatible with building a conventional wall
That's not to say there isn't a way to build a wall;
- one way to build a block wall is to use piles through the root system and ground beams with a base resting on the top of the soil
- another way is to use a standard rear garden system of lightweight pre-cast piers with concrete planks at the bottom between them and timber infill panels above these.
You may be able to view the application drawings online or you may wish to have a building professional research them for you and issue a planning file report.
If you are concerned with the measures approved to protect the trees, you may raise the matter with the Parks department.
This is not to object to the development, but ti ensure that the work is monitored to ensure the trees are protected.
FWIW
ONQ.
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