Get a bus map. Follow the routes which serve the schools outwards until you reach an area where the 'streety bit' / 'green bit' balance meets you 'semi-rural' criterion?
Painswick is very 'desirable' and actually attractive to go with it, which doesn't necessarily follow. (I was a bit shocked to discover that my mum's old house has moved from the lane it used to be in to the main road of the 'new' - 1970s
estate the other side of it, but Hey Ho, that's progress, I suppose). Closest to Stroud but also on bus routes into Cheltenham and Gloucester as well.