Where I am in the SW, about 40% of the local accommodation is under occupied 2nd homes and summer B&bs.
Local people just can't afford to live here.
The nearest neighbouring town (population 2000 is building about 500 homes, which is huge, but I cannot see who will buy them as there's no work.
It's a bizarre state of affairs because tourism whilst important economically, isn't the most important industry and recent local plans and reports highlight that increasing tourism (including B&bs and holiday lets) will actually cause more damage to the local economy and environment.
Some villages have already reached saturation and are utterly unaffordable for locals, meaning local provisions (schools, doctors, shops etc) are closing leaving fewer and fewer places to go and build a life.
It's a land grab by the rich which drives it.
So whilst I don't see green spaces in the desirable locations being overbuilt, the less desirable but important green spaces around are being overbuilt.
Billy's comments up thread were bang on.