Town hall officers have been busy clearing up 1,500 planning enforcement cases dating back to 2001.
In 2016 the council uncovered 1,500 historic cases that were still open. Less than 40 per cent of those were under four years old.
As a result it set about following up on the 15-year-old threats, and trying to close the more recent cases before it was too late.
That project has been "extremely successful", according to a performance review report, and 1,189 - 78pc - of those cases have been closed.
Enforcement officers are still getting an average of 55 new complaints every month, but are now working through those quicker as well.
There are currently 752 open planning enforcement cases.
The report says: "Many of the historic cases require legal action to progress and are resource intensive, and so resources are being aligned to recognise and deliver this through joint working with legal's litigation team."
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