Yes, very probably, and half the street has already done it. Listed buildings are rare here. Over two years, a few thousand planning applications have gone in. Most of the housing is post-war, which heritage officers rarely lose sleep over. In Fleet, the thing that stops an extension is usually the budget or the soil, not the rules.
Historic England's list records 42 listed buildings within Fleet's boundary: none at Grade I, 2 at Grade II* and 40 at Grade II. Listing covers the whole building, inside and out, so changing a listed home needs listed building consent on top of any planning permission, and the council will care about windows, materials and anything historic you might remove. In a town of this size, 42 is a small number. The odds that your house is one of them are low, and your conveyancer will tell you if it is.
Conservation areas are the other constraint, and the national register publishes none for the town. Hart's own planning maps name a Basingstoke Canal Conservation Area. If the garden backs onto the canal, check the council's map before assuming the lighter rules apply.
The real evidence is what the neighbours do. Hart's planning records show 3,069 applications across Fleet between April 2024 and June 2026, with 1,272 of them in the last twelve months. That's a town that keeps its builders busy. It proves people here apply to change their homes. It doesn't tell you how many were approved, and nothing on this page does. A yellow notice on a lamp post is the closest thing Fleet has to local gossip, and it's usually about someone's kitchen.
The ground deserves more attention than the paperwork. The British Geological Survey's shrink-swell mapping reaches class 3 at its highest in Fleet, covering about 9% of the area. Shrink-swell ground expands when wet and shrinks when dry, which can move shallow foundations, especially near thirsty trees. That isn't a reason to abandon a two-storey rear extension. It's a reason to get a structural engineer's view on foundation depth before the builder quotes, rather than after the first dry summer.
In practice, many single-storey rear extensions, loft conversions and outbuildings on unlisted houses outside a conservation area can proceed under permitted development, without a full planning application. The limits depend on the house type and what's been added before, so get a lawful development certificate from the council if you want certainty. Anything bigger, taller or closer to the boundary goes through a normal application, and the neighbours get a say. They'll use it.
Your freedom to extend a home is one of Fleet's real strengths. In most cases the council will allow it, and it's your ground and your neighbours you'll need to deal with.