Commenting on the draft revision of Circular 13/96, Planning and Affordable Housing, the institute believes a more positive approach is required.
Jon Morris, convenor of the RTPI's housing panel, said the institute welcomed the review of the circular, which proposed:
-- a reduction in the minimum size thresholds
-- clarification of the way in which financial or other contributions should be used
But he said: 'This draft does not address the wider relationship between the development planning system and the provision of affordable housing.
'The current arrangements have developed in a piecemeal fashion, which has allowed neither the planning system nor developers to play their most positive roles.'
The institute is also concerned that the revised advice continues to underplay the importance of the regional planning guidance and structure plans in establishing total housing need as a basis for striking a balance between market and affordable housing at district level.
Jon Morris said: 'Establishing quotas for affordable housing at district level would allow local plans to make site specific provision, increase certainty, and avoid the ad hoc, site-by-site basis of negotiating present provision.
'The institute does not support nationally prescribed thresholds, below which it is inappropriate to seek to negotiate the provision of affordable housing.'