You can extend a house in Winscombe, but how freely depends entirely on which house you bought. The area carries around 101 listed buildings and three conservation areas. Most ordinary homes sit outside both and keep the usual rights. The heritage stock does not. This is a village where the character you pay to live among is also the character that decides what you are allowed to do to it.
Start with the listed buildings, because they come on the tightest leash. Around 101 buildings across the area hold protected status: three at the top Grade One, seven at the middle Grade Two Star, and the bulk, about 91 of them, at Grade Two. Listing covers the whole building, inside and out, not just the handsome bit facing the road, so a listed home needs formal consent for work an unlisted one would never think about. New windows, internal changes, a rear extension, sometimes the paint and the roof tiles all fall under it. The rules exist to keep the building being the building, and they apply whether the change faces the street or hides round the back where nobody looks.
Then there are the conservation areas, of which the area has three. These do not freeze a house the way listing does, but they draw a wider net around it. Inside a conservation area the ordinary permitted-development freedoms are trimmed back, demolition and tree work can need consent that would be automatic anywhere else, and extensions get weighed against how they sit in the whole street rather than just your own plot. The aim is the look of the place taken together, which is the official way of saying your taste has quietly become a committee matter.
For most owners the practical line falls in a fairly predictable place. Buy a plain, unlisted house outside the conservation areas and you keep the standard permitted-development rights, so a modest rear extension or a loft conversion is often more a matter of paperwork than a battle. Buy into the older, protected stock and you are into full applications, specialist advice, and a timeline counted in seasons rather than weekends. The freedom is genuine at one end of the market and firmly fenced at the other, and the fence tends to run along exactly the streets buyers most want to be on.
So the verdict on your freedom to alter a home here sits low, about two out of five. You can extend in Winscombe, but the village's charm is stitched into listings and conservation boundaries, and the more of that charm your house carries, the more of your plans somebody else gets to sign off. Check the heritage status of the specific property before you fall for the picture of what you would do with it.