Proposed Submission Local Plan 2006-2028

Impact Assessments

8.96 The research report 'The Impact of Large Food Stores on Market Towns and District Centres' (1998) illustrates that large food stores can have an adverse impact on market towns and district centres, in particular smaller centres which are more dependent on convenience retailing to underpin their function, are more vulnerable to the effects of larger food store development at edge-of-centre and out-of-centre locations.

8.97 National guidance requires an impact assessment to accompany planning applications for retail and leisure development outside of Town Centres, which are not in accordance with an up to date Development Plan and exceed 2,500 sq m, or any locally set floorspace threshold[1].

8.98 Local research demonstrates that whilst most of the District's town centres are reasonably healthy, some are relatively small and lack Town Centre sites, and therefore could be vulnerable to the impacts of inappropriately scaled proposals. A gross floorspace threshold of 2,500 sq m would not be sufficient to assess the impact of convenience retail proposals on the District's centres as the majority of proposals over the last 10 years have fallen below this threshold[2].

8.99 The rural nature of the District and the size of its smaller centres, justifies a need to also look at the impact of any significant in-centre proposals, as these could also detract from the High Street and have an impact on its viability. LDF PMB paper 'Managing the Scale of Retail Development - A Methodology for Establishing a Local Retail Floorspace Threshold Policy for Impact Assessments'[3] outlines the methodology for establishing a local threshold for impact assessments. The floorspace threshold was primarily based on the size of existing convenience retail units in each settlement and guidance from the Valuation Office definition of foodstores (which are used to set rateable value). Policy EP12 sets out the threshold for Market Towns, District Centres and Local Centres. The national standard of 2,500 sq m applies to Yeovil, as it is the principal centre in the District.

8.100 The thresholds do not imply that anything above them are of an inappropriate scale and should not be awarded planning permission, but simply that anything at or above these would need to demonstrate that there would not be a significant adverse impact.

8.101 The requirement to undertake a retail impact assessment should not only be confined to major new developments, in some cases, extensions, redevelopment or variation of conditions can materially alter the effects of a development. The cumulative impact of recent/committed proposals may also be particularly relevant in some cases.

8.102 Where there is clear evidence that a proposal is likely to lead to significant adverse impacts, applications should be refused. The health of town centres (including vitality and viability indicators) and town centre or retail strategies should be considered as part of the assessment.

8.103 The floorspace threshold is generally related to the settlement classification for retail purposes, however both Ansford/Castle Cary and Somerton are exceptions. These District Centres both have a specific local justification to reduce the threshold from 500 sq m to 250 sq m. Neither Ansford/Castle Cary nor Somerton have a sizable 'anchor' supermarket in or on the edge of their town centre, and the range of shops that are present are generally small in nature, for example the largest comparison store in Castle Cary is 160 sq m. The delicately balanced nature of these town centres makes them more vulnerable to the impacts of large-scale retail and leisure developments than Langport which already has a large supermarket, hence their reduced threshold for Impact Assessments.

Policy EP12: Floorspace Threshold for Impact Assessments

In order to ensure that full consideration is given to the scale of development and whether this would have any significant adverse impacts, proposals involving additional retail floorspace, that is in excess of the following thresholds should be accompanied by a Retail Impact Assessment in accordance with national planning guidance.

Retail Hierarchy
Settlement Classification
South Somerset
Retail Floorspace
Threshold (gross)
Principal Centre Yeovil 2,500 sq m
Market Towns Chard, Crewkerne, Ilminster & Wincanton 750 sq m
District Centres Langport/Huish Episcopi 500 sq m
Ansford/Castle Cary & Somerton 250 sq m
Local Centres Bruton, Ilchester, Martock, Milborne Port, South Petherton & Stoke sub Hamdon 250 sq m

Proposals for retail developments up to and including the above floorspace thresholds will generally be regarded as being of a scale that would not result in significant adverse impacts.

Where Impact Assessments present evidence of significant adverse impacts on an existing town centre, development will be refused.


8.104 The delivery of retail schemes will be private sector led, but the Council will work in partnership to promote the District’s Town Centres as the first preferred location for town centre uses.

8.105 The following delivery bodies will be key in implementing Policy EP12:

  • South Somerset District Council;
  • Town and Parish Councils;
  • Developers and Landowners;
  • Infrastructure Providers.
Monitoring Indicators Target
Amount of retail floorspace developed both within and outside defined Town Centres
Focus new retail development in the defined Town Centre.
100% refusal of applications where Impact Assessments present evidence of significant adverse impacts on an existing town centre.
1. NPPF March 2012 [back]
2. See LDF Project Management Board paper 'Managing the Scale of Retail Development - A Methodology for Establishing a Local Retail Floorspace Threshold Policy for Impact Assessments', Core Strategy Workshop 9: 23rd November 2011 [back]
3. See Core Strategy Workshop 9: 23rd November 2011 [back]