He said: "In the NPPF there is still a bias in favour of brownfield, suggesting that all local plans should have that bias, but it’s not a bias that can come at any price."
Boles added: "It is true that some brownfield sites – it is not true of all brownfield sites – are much more expensive to develop. It would be simply irresponsible to say you can’t develop on any green space, any undeveloped land, until you developed all brownfield, because we simply don’t have the money to be able to pay for that and if you did that the rate of housebuilding would fall even further."
The NPPF document, published in March, says that "planning policies and decisions should encourage the effective use of land by re-using land that has been previously developed (brownfield land), provided that it is not of high environmental value".
Campaigners had warned that the draft NPPF had appeared to propose removing the "brownfield first" policy which requires housing developers to use previously developed sites before greenfield land.
The draft NPPF had omitted the term "brownfield". Instead, it said that, where practical and consistent with other objectives, "allocations of land for development should prefer land of lesser environmental value".
Boles, who was appointed planning minister in last month’s reshuffle, also told the fringe session that there are "positive early signs" following the publication of the revised NPPF earlier this year, but cautioned against drawing conclusions that the reforms will result in a dramatically different level of development.
He said: "More local plans have been created and adopted in the last 18 months than in the previous 10 years. Local authorities by and large are taking very seriously their responsibility to produce a plan. The whole thing can’t work without people doing that, and that’s encouraging."
Boles added: "The other thing that’s encouraging is that the rate of acceptance of applications has picked up a bit. But we all have to be realistic. The last year isn’t a normal year and the year before and the year before that weren’t normal years either as comparators. I don’t think we can yet absolutely draw conclusions that a dramatically different level of development is going to result."
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