Affordable Housing: Green Belt

Through the consultation on proposed reforms to the National Planning Policy Framework and other changes to the planning system last year, the government sought views on implementing ‘Golden Rules’ to ensure development in the Green Belt is in the public interest.

As set out in the formal response to the consultation published on 12 December 2024, we noted concerns that setting a national 50% affordable housing target could lack flexibility and fail to account properly for regional variation. The government has adopted an approach which balances the need for an ambitious affordable housing target with the viability challenges that may occur in some cases.

Local planning authorities will be able to set their own ‘Golden Rules’ in relation to affordable housing through their new local plans. The affordable housing requirement should: a) be set at a higher level than that which would otherwise apply to land which is not within or proposed to be released from the Green Belt; and b) require at least 50% of the housing to be affordable, unless this would make the development of these sites unviable (when tested in accordance with national planning practice guidance on viability).

Prior to development plan policies for affordable housing being updated in accordance with the revised NPPF, the affordable housing contribution required to satisfy the ‘Golden Rules’ is 15 percentage points above the highest existing affordable housing requirement that would otherwise apply to the development, subject to a cap of 50%. The 50% cap does not apply to rural exception sites or community-led development exception sites, or if the local planning authority has a relevant existing policy which would apply to the development which is above 50%. We estimate that under this model, the median Green Belt local planning authority affordable housing requirement will be 50%.

The government intends to update planning practice guidance on viability as part of our commitment to strengthen the system of developer contributions. Prior to new viability guidance being published, site specific viability assessment should not be used on schemes where the ‘Golden Rules’ apply.