I still haven't, as I promised, addressed in detail the CPRE's latest "overcrowded Britain" nonsense, but here's a very very simple refutation:
The tiny dark blob dead centre of the map is Birmingham.
Remember, by 2035, "The countryside is all but over". Except for nearly all of it, which you can only see from the air, because, er, no-one lives there.
See also this economics piece, by Robin Hanson at Marginal Revolution, on the positive externalities of urban expansion.
We also neglect the benefits we provide others when choosing to live at the edge of the populated area, versus living in an unpopulated area... Local governments are in a position to reduce this externality, but they seem to mostly make matters worse. Minimum lot sizes, maximum building heights, maximum densities, and barriers to development at the populated edge are far more common than their opposites.