Edgelands: Journeys into Britain's True Wilderness by Paul Farley and Michael Symmons Roberts is a delight. It's a worthy successor to Richard Mabey's The Unofficial Countryside, recently republished, a guide to the unexpected wildness found in and around London in the gaps in development, construction sites, allotments, riverbanks. It also reminded me a bit of Remains of Elmet by Ted Hughes and Fay Godwin.

Roberts and Farley grew up near Bolton in Lancashire, not far from my own childhood in either space or time, and they evoke marvellously the freedom children in that time and place had to wander around the countryside that lapped up and into the edges of northern mill towns. But they roam widely through modern borderlands throughout the country – around office and retail parks, under motorway flyovers, through derelict factories, along the side of major roads. They have an acute eye for the vigour of nature in these man-made landscapes, and for the kinds of low-status and semi-outlaw activity that any edgeland anywhere will accommodate. So there's social analysis as well as nature writing here. The book is beautifully written, as well.

It sent me to look at the report Kate Barker wrote for the last government on the madness of the UK planning system. This makes it almost impossible for new homes and commercial buildings to be built where people want to live and work. One result is that the price of land with planning permission is many multiples of the price of any other land (Paul Cheshire and Christian Hilber did the background research on this for Kate's review). In England and Wales excluding London at the time of the review, land with no planning permission was valued at £10,000 per hectare, land with permission for business use at £779,000 per hectare, and with permission for residential development £2.6m per hectare. Of the 15 most expensive locations in the world for commercial space, five are in England. Rents in Manchester and Leeds are similar to midtown Manhattan.

A second result is that only a small fraction of the land in England has been developed. In every region outside London only 10-15% of the total land area has been developed, the rest being either water or 'greenspace' – albeit much of it edgelands rather than 'true' countryside. Is it worth the price? My inner child and inner free market economist might just be at odds over this one.