5.1.1. PPW states: "The planning system must: promote viable urban and rural retail and commercial centres as the most sustainable locations to live, work, shop, socialise and conduct business; [and] sustain and enhance retail and commercial centres' vibrancy, viability and attractiveness" (paragraph 4.3.3 refers).

5.1.2. The Vale of Glamorgan retail hierarchy comprises of the town, district, local and neighbourhood centres identified within Policy MG12, and excludes any existing edge of centre or out of town retail parks within the Vale of Glamorgan. Policy MG 13 reinforces the principle of national policy that retail and similar development is best located in our existing retail centres where they are readily accessible by sustainable transport methods and where such uses can complement one another to reinforce the role and function of sustainable settlements. Therefore, it requires developers to demonstrates that edge or out of centre retail must be needed and it would not have an unacceptable impact on the main retail centres.

5.1.3. Existing edge of centre and out of town retail areas in the Vale of Glamorgan have been identified at the following locations:

Edge of Centre

• Barry: Barry Waterfront; Palmerston; Pencoedtre; Highlight Park
• Penarth: Terra Nova Way

Out of Town

• Culverhouse Retail Park, Culverhouse Cross
• Brooklands Terrace Retail Park, Culverhouse Cross
• Valegate Retail Park Culverhouse Cross
• Penarth Road Retail Park

5.1.4. Proposals for new retail development in edge and out of town retailing areas will be strictly controlled in accordance with national policy, in order to support existing established retail centres in the retail hierarchy.

5.1.5. Policy MG13 sets out the criteria by which proposals for new retail development in edge and out of town locations will be assessed in line with national policy. It applies to all proposals that create additional retail floor space, including changes of use, extensions, the subdivision / merger of existing units, mezzanine floors and variations to relevant planning conditions.

5.2.1. TAN 4 reinforces the need for retail developments outside retail centres to demonstrate additional need. It does not prescribe the methodology for assessing retail need but advises that developers should ensure assessments are prepared in a clear logical and transparent way with the use of robust and realistic evidence.

5.2.2. Quantitative need assessments usually include:

• Existing and forecasted population levels and distribution.
• Forecast expenditure for specific classes of goods to be sold, within the broad categories of comparison and convenience goods, which are provided at the lowest geographical area possible to reflect local circumstances.
• Sales density data for both existing and future retail provision which is realistic and benchmarked against similar retail developments in the area; and
• Catchment areas for centres and individual stores which reflect the size and scale of the development and the likely draw of a particular scheme.

5.2.3. Where additional need is demonstrated, developers will need to prove that it cannot be met within an existing town or district retail centre by following the sequential test locational preference for retail, leisure and other complementary uses:

• Firstly, within retail and commercial centres identified in the retail hierarchy where suitable sites, or buildings for conversion are available. The planning application must be of an appropriate scale in relation to the role and function of the centre.
• If no suitable sites are available in retail and commercial centres then edge-of-centre locations should be considered, with preference given to brownfield sites that are or will be well connected to the existing centre and accessible by a variety of means of transport, particularly walking, cycling and public transport.
• Only when retail and commercial centres and edge of centre locations have been considered and found to be unsuitable can out-of-centre options within, and then outside, a settlement area be considered. Where out of centre sites are concerned preference should be given to brownfield sites which are or will be well served by a choice of means of transport and are close to an established retail and commercial centre.

5.2.4. Where a developer favours a development site on the edge of or outside a retail and commercial centre the developers will need to provide evidence to explain why potential sites or buildings within the centre are unable to accommodate the format, scale and design of a proposed development. Developers will be expected to be reasonably flexible in this regard having regard to wider planning principles like sustainability and accessibility. TAN 4 states: "Developers and retailers should be flexible and innovative about the format, design and scale of proposed development and the amount of car parking needed, tailoring these to fit local circumstances."

5.3.1. In addition to demonstrating need and that the sequential test for location has been applied, developers must show that their proposals for retailing on an edge or out-of-centre location would not either individually or cumulatively with other recent or proposed consented developments have an unacceptable impact on the trade, turnover, vitality and viability of the town, district, local or neighbourhood centres.

5.3.2. PPW recognises that retail developments outside designated retail and commercial centres can impact on the viability and vibrancy of a centre. Impacts resulting from such development, whether individual or cumulative, may include changes in turnover and trading ability, consumer choice, traffic and travel patterns, footfall, as well as affect centre regeneration strategies and existing or proposed retail sites allocated in the development plan. The purpose of the retail impact assessment is to consider these issues and determine if these developments are likely to have detrimental consequences.

5.3.3. PPW sets a threshold where a retail impact assessment is required for applications that are proposed on the edge of or outside designated retail and commercial centres of 2,500 sq. metres or more gross floorspace. For smaller retail planning applications, it states, planning authorities will need to determine whether an assessment is necessary, for example when a smaller proposal may have a significant impact on a centre. These will be assessed on a case by case basis and developers should seek pre-application advice for more information about specific requirements relating to the precise location, scale and form of development proposed.

5.3.4. Where planning permission is granted for new edge and out-of-centre retail development conditions may be imposed to control the nature and scale of the retail activity and to minimise any potential impact on the existing retail centres within the retail hierarchy.

5.4.1. The aim of Policy MG 13 is to preserve and enhance the vitality, viability and attractiveness of existing town, district local and neighbourhood centres as well as promoting sustainable communities and sustainable travel patterns. In this regard, proposals for small shops that serve a local neighbourhood or rural village, and farm shops will be favoured outside existing retail centres.

5.4.2. Furthermore, the LDP recognises the importance of local neighbourhood shops and Policy MD 5 states that development within settlement boundaries will be permitted where it would not result in the unacceptable loss of community facilities which could include a local shop, post office or public house.