Most single storey extensions in Maidstone and the surrounding villages do not need planning permission at all, because they fall under what is called permitted development. The catch is that the rules are precise, and getting them wrong can mean an enforcement notice or a headache when you come to sell. Here is what actually matters, in plain terms.
Permitted development rights let you extend a house without a planning application, provided the extension stays within set limits. For a single storey rear extension on a semi detached or terraced house, that means projecting no more than 3 metres beyond the original rear wall. On a detached house the limit is 4 metres. The extension must be no taller than 4 metres overall, and if any part sits within 2 metres of a boundary the eaves must not exceed 3 metres.
There is also a larger home extensions route, sometimes called prior approval, which allows up to 6 metres on a semi or terrace and 8 metres on a detached house. It is not automatic. You notify the council, they consult your neighbours, and if nobody raises a valid objection within 42 days you can build. We use this route regularly for kitchen extensions where 3 metres simply is not enough for an island and dining space.
Permitted development rights do not apply everywhere. If your home is a listed building, or sits in a conservation area, planning permission is far more likely to be needed. Maidstone borough has several conservation areas, including parts of the town centre, Bearsted, Loose and Boxley, and villages across the borough have their own designations. Flats and maisonettes have no permitted development rights at all, so any extension needs an application.
You will also need permission if a previous owner already used up the permitted development allowance, or if the developer removed those rights when the estate was built, which is common on newer developments around Langley and Kingswood. It is worth checking the original planning conditions before assuming anything. A householder planning application to Maidstone Borough Council currently costs 258 pounds and a decision typically takes around 8 weeks from validation.
If your extension is permitted development, we strongly recommend applying for a lawful development certificate. It costs half the fee of a full application and gives you formal confirmation from the council that the work was lawful. Without one, you may struggle to prove it when selling, because buyers' solicitors increasingly ask for evidence rather than taking your word for it.
Separately, building regulations approval is needed for virtually every extension regardless of planning status. That covers structural work, insulation, drainage, electrics and glazing. It is a completely different process from planning, handled either through the council's building control team or an approved private inspector, and inspections happen at set stages during the build.
A typical example: a 1930s semi in Penenden Heath wanting a 4 metre rear kitchen extension. That is beyond the 3 metre limit, so it went through prior approval. The neighbours had no objections, approval came through in six weeks, and the build started on schedule. Had the owners assumed 4 metres was fine without checking, the council could have required alterations after the fact.
Our honest advice is to sort the paperwork before ordering materials or booking a builder. Checking your position usually takes a phone call to Maidstone Borough Council's planning department or a look at your property's planning history online, and any reputable local builder should be happy to talk through the constraints on your specific plot before quoting.
A householder application normally takes around 8 weeks from validation, though it can stretch longer if the case officer requests amendments. Prior approval for a larger extension has a fixed 42 day neighbour consultation period.
Yes, almost always. Building regulations are separate from planning and cover the structure, insulation, drainage and electrics, with inspections at key stages of the build.
If you are within permitted development limits, neighbours cannot block it, though the Party Wall Act may apply if you build near the boundary. Under prior approval or a full application, objections are considered but only on valid planning grounds such as loss of light.
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