14/10/2026
If a property includes a room, extension or sunroom built without approval from the local council, that counts as a planning irregularity, and it follows the property, not the person who built it.
It matters for three practical reasons. Your mortgage could be refused, since the bank's surveyors will spot the irregularity and it can hold up approval of your home loan. It can cause problems when you sell, because the irregularity transfers with the property and any future buyer will face the same concerns. And there is a risk of fines, since the council can require the works to be legalised, where possible, or demolished.
The solution is straightforward: before signing the promissory contract, have the property's documents and plans checked against council records.
Buying property? Validate the documentation before you pay the deposit.