9.82 The Government within PPS4 has confimed use of the sequential approach to site selection for town centre uses. Under this approach planning authorities should identify sites that are suitable, available and viable in the following order:

• appropriate locations in existing centre where sites or buildings for conversion are, or are likely to become, available within the plan period:
• edge-of-centre locations with preference going to sites that are or will be well connected to the town centre;
• out-of-centre sites, with preference given to sites that are or will be well served by a choice of transport, and which are closest to the centre and have a higher likelihood of forming links with the centre.

9.83 The definitions of centre, edge of centre and out of centre are set out in Appendix B to PPS4.

9.84 PPS4 sets out in some detail what is required to comply with the sequential test for proposals outside centres and how the impact assessment is to be conducted. Proposals must exceed 200 sq m gross for retail and leisure uses for the sequential approach to be required.

9.85 PPS4 also requires an impact assessment to be applied for all developments outside town centres and for schemes above 2,500 sq m gross floorspace. In advance of development plan clarification of this floorspace limit the impact assessment must apply to all developments of this type. (An impact assessment also applies to proposals within centres that are not in accordance with the development plan whose impact may adversely affect other centres). Work is ongoing to establish a relevant threshold at which to set the impact assessment threshold level for the South Somerset town centres (to be available for the Submitted Core Strategy document).

9.86 Applications for town centre uses that are not in an existing centre and not in accordance with an up to date development plan should be refused planning permission where the applicant has not demonstrated compliance with the sequential approach to site selection, or where there is clear evidence that the proposal is likely to lead to significant adverse impact on the existing centre. Where no significant adverse impacts have been identified, planning applications should be determined by taking account of the positive and negative impacts of the proposal, any other material considerations and the likely cumulative effect of recent permissions, developments under construction and completed developments.