Draft A27 Chichester Bypass Mitigation Supplementary Planning Document (SPD) Version 2 - May 2024

4.0 Planning Contributions

Level of funding to be secured

4.1 Section 2 (Table 1) above sets out that a minimum of £33.1 million will be needed to fund the remaining A27 junction improvement works which are provided for within Policy 8 of the Local Plan. These are set out in detail within the Transport Study of Strategic Development Options and Sustainable Transport Measures (2013). These works relate to improvements at Fishbourne, Stockbridge, Whyke and Bognor Road junctions.

4.2 The overall level of residential development that will be affected by this SPD cannot be known with certainty. This is because it is largely comprised of windfall development and there is also no certainty over when the new Local Plan will be adopted. However, based on the Council's recent monitoring and the anticipated programme for the Local Plan Examination, the total number of dwellings is anticipated to be in the region of 250. However, this number could change if more or fewer homes are permitted each year or if the adoption of the new Local Plan is delayed.

4.3 In the absence of any additional sources of funding, this would result in a notional contribution per dwelling of £54,240 (£13.56 million ÷ 250 dwellings).

Viability testing

4.4 It is clear that the level of contribution referred to above would render all residential development in the District unviable. Therefore, in order to determine what level of contribution would be feasible, on an average contribution per dwelling basis, local plan viability testing evidence has been used. This evidence was undertaken to support the Proposed Submission Plan in January 2023 ^[6] and tested a wide range of potential financial contributions for A27 mitigation across a number of different residential 'typologies' (scenarios) that are consistent with the nature of development coming forward within the District.

4.5 The outcome of the viability testing was that the majority of development typologies across the south of the District were found to be sufficiently viable at a contribution level of up to £8,000 per dwelling.

Calculation of planning contributions

4.6 Following the outcomes of the viability evidence, £8,000 per dwelling has been used as a 'Target Contribution Level'. This is effectively a starting point against which other factors, such as the location of development and the size of the dwelling (i.e. likely level of car ownership) can be applied. This ensure that the financial contribution applied to development is fairly and reasonably related in scale and kind.

4.7 As the 2016 SPD was based on a contribution apportionment approach that excluded windfall developments and other schemes under 50 dwellings, the Council has developed an alternative apportionment methodology which can be applied to all residential developments within the south of the District. This is based on up-to-date data taken from three sources:

• 2021 Census Household and Car ownership data;
• Department for Transport (DfT) National Trip End Model Car Ownership forecasts; and
• The Chichester Area Transport Model.

4.8 The analysis has been undertaken at Ward level for all wards in the south of the District, numbered 1 to 14. These are shown in Figure 1 below and also in Appendix 1:

Figure 1: The 14 Wards south of the National Park

4.9 The methodology first determines a factor at ward level that is based on car ownership. The data is sourced from both the 2021 Census for current levels of ownership and from the DfT National Trip End Model version 8.1 to provide car ownership forecasts for 2029. Car ownership is used as a proxy for likely car trips and it is expected that in addition to dwelling size influencing car ownership, this will also be influenced by site proximity to a good range of amenities or good sustainable transport links. Lower car ownership results in a lower per dwelling contribution.

4.10 The Chichester Area Transport Model, is then used to determine the likely impact of dwellings on the A27 Chichester Bypass. This model has been used to determine the number of trips from each site (combined at ward level) that reach the A27 Chichester Bypass. This includes trips which may only cross over the A27 at one of the six junctions, as well as those that travel along the bypass.

4.11 The outcome of this is the matrix presented in Table 2 below, which provides an 'Apportionment and Averaging Factor' for each of the 14 wards by dwelling size.

Table 2: Apportionment and Averaging Factors

4.12 The relevant Apportionment and Averaging Factor is then multiplied by the Target Contribution Level (£8,000) for each dwelling to derive the contribution for that dwelling. An example is shown in Table 3 below for a development with a net increase of five dwellings in East Wittering.

Table 3: An example of how the contribution can be calculated (for the Witterings)

Total A27 mitigation contribution that will be required

4.13 It is important to emphasise that the Total Contribution that may be calculated using the method described above is indicative only, based as it is on guidance provided by this SPD. In order for residential development within the south of the District to be acceptable to the Council, it must be consistent with the Local Plan as a whole ^[7], including Policy 9 (Development and Infrastructure Provision). Applicants are therefore advised to check with the Council about the level of A27 mitigation contributions that will be required for any given proposal, either during pre-application engagement or following submission of a planning application.

Development to which the contributions will apply

4.14 The A27 mitigation contributions will apply only to any net increase in new dwellings coming forward in the area to the south of the National Park (see Appendix 1). The contribution will be sought from all new dwellings, including from affordable homes, retirement homes (such as sheltered housing) and from self or custom-build homes.

Demolitions and dwelling conversions

4.15 If a development involves the demolition of any dwellings or the conversion of a larger dwelling into multiple smaller dwellings, the total contribution for the dwellings to be lost can be calculated and deducted from the overall contribution for the development as a whole. The overall contribution for the development cannot fall below zero.

Development to which the contributions are unlikely to apply

4.16 There are some cases where the A27 mitigation contributions are unlikely to be sought and these are set out below. The list below is not exhaustive however, and where applicants are in doubt, they are advised to ask about this during pre-application engagement with the Council.

Care homes / Extra Care facilities (Use Class C2)

4.17 Older and disabled persons care homes (including Extra Care homes) are generally for people who do not own or drive cars and so tend to have a very small or negligible impact on the A27 Chichester Bypass. For private care homes or Extra Care homes where parking spaces are provided for residents (beyond the normal level of visitor parking), the Council will consider applying the A27 mitigation contribution.

Purpose-build student accommodation

4.18 As with care homes, purpose-built student accommodation does not tend to provide parking spaces for the occupants or allow for the use of cars by students. These types of accommodation tend to be located within urban areas with good access to sustainable modes of travel. For student accommodation schemes where parking spaces are provided for occupants (beyond an appropriate level of visitor parking), the Council will consider applying the A27 mitigation contribution.

Holiday lets

4.19 For accommodation (whether a building or caravan) where the planning permission is for short-term holiday lets, it would not be appropriate to apply the contribution as this could result in double-counting the impact on the A27, to the extent that those using the lets may live within the south of the District. In addition, there is no viability evidence to support applying a financial contribution to the delivery of holiday accommodation.