Dear Law Denning,
The covenant is as follows:
(4) Not to alter demolish or make any additions whatsoever to the property or outbuildings or to erect any further outbuildings or boundary walls or fences without previously submitting plans showing such alterations additions or erections and obtaining consent of the Head of Housing for the time being of the Council in writing thereto (in addition to any planning permission or building regulation consents) such consent not to be unreasonably refused and in particular but without prejudice to the generality of the foregoing:-
(a) Not to erect any fence or wall or cultivate any hedge which exceeds the following heights
(i) along the front boundary of the property hereby conveyed one metre
(ii) along the side boundaries of the property hereby conveyed one and a half metres
(iii) along the rear boundary of the property hereby conveyed two metres
(b) To ensure that any fence or wall erected by the Purchaser is of the same type as those in the immediate vicinity
To me, this suggests it was written specifically to limit fence and hedge heights, and that they are applying the covenant unreasonably. No matter; we will go for planning permission, and if planning consent is given, use this to note that their refusal would be unreasonable (Rickman v Brudenell-Bruce  ?), and that we may, regrettably, have to sue for breach of covenant.
However, first steps first. My query is: Planning have said they will not validate my application until there is written consent from the arms length management organisation of the other semi-detached property. Are Planning within their rights to require this? If not, given that we have excellent relations with the Planning Officer, who I suspect is being leaned on with regards XXXXX XXXXX requirement, how can we politely, but firmly, note this?