Some of these arguments came to a head in a summit session entitled 'Can growth be green?' It concerned a live case study to build tens of thousands of homes on a Green Belt site to the north of Harlow New Town. Leaving aside the local political complexities (the land is in east Hertfordshire rather than Harlow), the question raised was whether one could justify building on Green Belt, given the concerns expressed above. Making the case in robust style was Paul Murrain, a senior design adviser at the Prince of Wales Foundation. His argument was simple: you could achieve greater bio-diversity in a housing and mixed-use scheme than the current agricultural use, and use the relatively dense development as a trigger to regenerate tired old Harlow.