@colly
Hello
I am a full time planning enforcement officer so what you describe is my everyday work.
I can't go into the specifics of this case as I have no personal involvement but might be able to help in some respect, I gather that you may have done elements of what I shall write.
Typically when planning permission is granted it is expected that the recipient of the permission or the developer carry out the development in accordance with the approved plans. If you do not then you do so at your own risk.
As a amember of the public if you suspect that a breach of planning control has occured then you may report it to your local planning authority's (LPA) enforcement team. Some Council's call it planning compliance or similar but they all do the same job.
Any new allegation will be investigated and brought to a conclusion.
The alleged breach that you describe would potentially sound like the buildings and/or site levels are higher than approved. If I were investigating this, and I have dealt with many cases of this nature, I would be providing the approved plans to a surveyor who would then go out and measure the levels and heights. Usually the surveyor will return the approved plans with his measurements annotated on the plan. If the measurments are the same then there is not breach of planning control and the LPA will not be able to take enforcement action.
If one still has concerns relating to privacy light, amentity at this point it is frankly too late. The application process has a consultation period and it is at this point for theses issues to be addressed.
Coming back to the survey, if the measurements are different to the approved plan then you have a breach of planning control. What happens next is dependent on what sort of error has occured, clearly if the height of a building is supposed to be 5 metres and is instead 15 metres it probably is unaceptable and the route will be to have this rectified, either volunatarily of with the COuncil serving an enforcement notice. If the building is supposed to be 5 metres in height but instead 5.2 metres then the officer should be encouraging the developer to rectify this retrospectively and there are different mecahnics to achieve this dependant on the specificas of the breach. If the developer is unwilling then the Council will have to "write the case up" for non expediency. WHat this means essentially is writing it off in a formal report. The purpose of planning enforcement is ultiumately to regularise harm, if the breach is not causing suficient harm (and that harm is based on the LPA's development plan, the National Planning Policy Framework [NPPF] and any other material considerations) then the LPA should not take action. Enforcement action is not punative, it is not there simply to punish someone for their error, regardless of intentional or otherwise.
Your local authority will have done their job properly if they have gone through the steps above (admittedley cut down for a lunch time post on cyclchat!). When LPA's decisions are challenged by a claim to the ombudsmann they will be looking at whether the COuncil has procedurally done the correct thing, they will not be questioning the actual decision.
Hope this helps, if you have any direct questions I would be happy to try and help.
Darren