Solving London's housing crisis

I see Richard Rogers had a piece in the Evening Standard last night calling for a greater focus on design and brownfield as the means of solving London's housing crisis. I confess to being deeply puzzled. In 1999 the Urban Task Force (chaired by Richard Rogers) advocated precisely this solution. The report received cross-party support and underpinned Labour's approach to urban and regeneration policy. For example, Labour introduced a 60% target for the proportion of development that should occur on brownfield land. Unlike most housing targets, this one was actually met with many Local Authorities achieving considerably higher proportions of development on existing sites.