The perceived quality of public funded schools varies tremendously. Increasingly parents are sending children to private schools. However, it is unsurprising that parents have been willing to spend a premium to move to an area which can guarantee entry into a "good school".
It is not surprising if you consider that the alternative to going to a good public sector school is spending £5,000 a year on private education.
For parents with this choice, living in an area of a very good school could be worth upto £5,000 * 7 = £35,000.
A university study examined links between house prices and state schools and found that
Research, carried out by the University of Warwick's Department of Economics, said parents were willing to pay up to £20,000 extra to buy into areas with the best schools. - link at BBC
Good schools raise House prices at BBC
If you live in the catchment area of a good school, but have no children of school age, it might be worth moving and cashing in on the school premium.
See also: What determines house prices