You can, but check the paperwork before you pick a builder. The town holds more listed buildings than its reputation would suggest. A string of conservation areas cuts through it. There are ancient monuments within sight of the housing estates. The neighbours keep applying anyway, by the thousand.
The area has 269 listed buildings. Five are Grade I, the top tier, 11 are Grade II* and 253 are Grade II. Listing covers the whole building, inside and out, not only the front elevation, so an extension, a new window, a replacement door or a knocked-through wall all need listed building consent on top of any planning permission. Doing the work without it is a criminal offence, not a paperwork slip. For a town that people assume went up in the 1960s, 269 is a lot of history to work around.
There are 11 conservation areas in and around the town, including Basingstoke Town, Fairfields, Brookvale West, Park Prewett, Old Basing and Sherborne St John. Inside one, the council takes an interest in things you'd normally never think to ask about, such as roof materials, front boundaries, cladding and trees. Some of the building work that needs no application elsewhere does need one here. The line on the conservation-area map matters more than whether your house looks old.
The area also has 8 scheduled monuments, the strictest protection tier, from Winklebury camp, an Iron Age hillfort, to the remains of Basing House. Scheduling rarely touches an ordinary garden, but if your land borders one, any digging near it needs a separate consent, and the answer is often no.
None of this is stopping anyone. From April 2024 to June 2026, the area logged 4,050 planning applications, 1,703 of them in the last twelve months alone. That's a steady stream of people trying to add a room, a storey or a garage conversion. If you're on an estate and wondering whether it's allowed, a walk round the block will usually turn up a neighbour who has already done it.
In practice, most of the town is the post-war and later housing that sits outside all of this. On an ordinary house there, many single-storey rear extensions, loft conversions and outbuildings can go ahead under permitted development, the national rules that allow some work without a full application. Those rights disappear for listed buildings, shrink inside conservation areas and don't apply to flats at all. Some estates also had their rights removed by condition when they were built. Before you commit to anything, ask the council for a lawful development certificate, or check the property's planning history, so you're not relying on what the seller says about the conservatory.
Extending in Basingstoke is harder than the estates make it look. The town carries more protected buildings and designated areas than most buyers expect, so find out which side of each line your house sits on before you draw up plans.