Stamford is one of the most protected towns in England, so the honest answer is: it depends on where in town you live and what you want to build. Many extensions can still go ahead under permitted development, but the conservation area and the town's hundreds of listed buildings catch a lot of people out. Here is what to check before you spend anything on drawings.
If you own an unlisted house outside the conservation area, a modest extension often needs no planning permission at all. Permitted development rights let you build a single storey rear extension up to 3 metres deep on an attached house, or 4 metres on a detached one, provided it stays under 4 metres high and uses materials that broadly match the existing house. Go deeper, up to 6 metres attached or 8 metres detached, and you can use the prior approval route, where South Kesteven District Council notifies your neighbours before confirming you can proceed.
There are other limits that apply everywhere: the extension must not cover more than half the garden, must not wrap around the front of the house facing the road, and side extensions must be single storey and no wider than half the original house. Two storey rear extensions are possible under permitted development but the rules are tighter, including a 7 metre gap to the rear boundary.
A large slice of Stamford, essentially the historic core and streets running off it, sits within a conservation area, and the town has several hundred listed buildings. If your house is in the conservation area, permitted development shrinks considerably: side extensions need planning permission, the larger 6 and 8 metre prior approval route is unavailable, and cladding the outside of the house is not permitted. Two storey rear extensions also need a full application.
If your house is listed, the position is stricter again. Almost any extension, and plenty of internal work, needs listed building consent on top of planning permission. Carrying out work on a listed building without consent is a criminal offence, not just a planning breach, so this is the one situation where we would never suggest starting without paperwork in place.
A householder planning application in England currently costs £528, and South Kesteven typically decides within eight weeks of validation, sometimes longer if the conservation officer is involved. On top of the fee you will need drawings, usually from an architect or architectural technician, which for a typical extension tend to run from around £1,500 to £4,000 depending on the size of the project and the level of detail needed.
Bear in mind that planning permission is only half the story. Building regulations approval is a separate process and applies to virtually every extension regardless of whether planning permission is needed. It covers structure, insulation, drainage, electrics and escape windows, and is signed off through inspections during the build. If you are extending near a shared wall or boundary, the Party Wall Act may also require formal notice to your neighbour.
Even where an extension looks like permitted development, we recommend applying for a lawful development certificate, which costs half the planning fee at £264. It is written confirmation from the council that your extension is lawful, and it matters enormously when you come to sell, because buyers' solicitors increasingly ask for proof rather than taking a homeowner's word for it.
We build extensions across Stamford, Peterborough and the surrounding villages, and the pattern we see is consistent: the projects that run smoothly are the ones where the planning position was pinned down before any materials were ordered. A free chat at the start about what your plot and street will realistically allow costs nothing and can save months. If you are unsure where your house stands, ask the council for pre application advice or talk to a builder or designer who works in the town regularly and knows how the conservation officers tend to respond.
South Kesteven District Council publishes a conservation area map on its website, and Historic England's online register shows listed buildings. If you are still unsure, a quick call to the council's planning department will confirm it.
South Kesteven District Council aims to decide householder applications within eight weeks of validating them. Applications involving listed buildings or conservation area concerns can take longer, so allow three to four months from first drawings to a decision to be safe.
Legally you can build at your own risk, but we would strongly advise against it, especially in Stamford. If the application is refused you could be ordered to take the work down, and on a listed building starting without consent is a criminal offence.
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