Economists recognise that many private activities have "externalities." which can be positive or negative. In the pre-politically correct days when I taught in an all-boys school we used the example of the girl wearing a mini-skirt, who had the private satisfaction gained from the knowledge that she was in fashion,and we had the public benefit of being able to admire her legs, as a positive externality. Unacceptably sexist today, I know, but they did remember it.
In housing, or any other building for that matter, an elegantly designed structure gives private satisfaction to its owner, and the rest of us have the pleasure of enjoying the sight of a well proportioned building from the street. An ugly carbuncle of an extension (up to 8 meters in length!) badly sited conveys a negative externality to the neighbours and any passers by. Planners exist, among other things, to ensure that private development activities have at least a neutral impact on the rest of us. The Pickles proposals to scrap planning requirements, even for a limited period, illustrate the Tory attitude that the "haves" can do as they (we) like and devil take the rest of us.
Secondly, this "do as you like in your own back yard" policy shows that the government at last recognises the need for an investment stimulus to the economy, but is too hidebound by its ideology to finance it through effective public works on the required scale If the relaxation of planning laws promotes any demand at all to the building industry, it will be a sad little nibble at the problem rather than the massive bite of public investment which is needed, but which the government lacks the courage to attempt.
Thirdly , the proposal to remove the requirement for a proportion of newly-built houses to be affordable means that the building industry can concentrate on houses for the haves but neglect the sector in which additional housing is most urgently needed - for those with more limited means.
Finally, the removal of the requirement for affordable housing encourages the ghettoisation of Britain,with the well off comfortably in their enclaves and the less well-off kept at a safe distance, as though the errors of the mass one-class housing estates of the post-war period have never been learned. I have not yet read it, but I understand that Professor (of geography) Danny Dorling's recently published "So You Think You Know About Britain" amply illustrates the folly of this policy.