This is an interesting addition to the debate on delivery of new homes and the issue of developers hoarding land with planning consent to maximise returns.
Having seen and been involved in large scale brown field sites this reflects personal experience in the pace of delivery. If we are to resolve the issues over delivery of the homes we need then matters such as this need to be addressed alongside any issues over delivery of homes once planning permission has been obtained.
Nathaniel Lichfield & Partners recently published a study which analysed a group of 70 large sites, measuring the average planning approval period (the period from the validation date of the first planning application to the decision date of the first application which permits development on site). They found that the average planning approval period for schemes of more than 2,000 dwellings is 6.1 years. If Local Plans and five year land supply assessments are to place greater reliance on large scale developments the assumptions they use about how quickly sites will deliver homes will need to be properly justified. Finally, in considering the pace of delivery, large-scale brownfield sites deliver at a slower rate than equivalent greenfield sites. 50% more homes per annum are delivered on average on large greenfield sites than large brownfield sites.