As far as I can ascertain, in England there is no fixed distance between windmills and residential dwellings. Wind farm development applications of >50MW are handled at national level, smaller farms at local planning authority level. Each authority may fix its own rules on distance, or simply treat each application ad hoc. The sort of distances that seem to be required go from 350m to 800m, with 500m being generally considered sufficient.

1,500 metres has been called for (particularly by opponents) in certain cases, but it is not a rule.

Scottish planning policy says: "A separation distance of up to 2km between areas of search and the edge of cities, towns and villages is recommended"

but that is a recommendation that doesn't concern individual dwellings.