Proposed Submission Local Plan 2006-2028

Affordable Housing Thresholds

9.22 In order to maximise the delivery of affordable housing the threshold should be set as low as possible so that as many sites as possible contribute towards the delivery of affordable housing, where it is viable to do so.

9.23 South Somerset has traditionally delivered a significant proportion of its new housing on small sites[1]. Evidence shows that on supply and viability grounds a threshold of 6 dwellings would be acceptable in general terms across the District. Whilst this evidence also suggests that the corresponding area equivalent should be 0.1 ha, this is based upon 60 dwellings per hectare (dph)[2]. However, the average net density across the District is approximately 28 dph[3] therefore a threshold of 0.2 ha has been applied reflecting a net dwelling density of 30 dph. This means that any development proposal for 6 dwellings or more (or on a site of 0.2 ha or more irrespective of the number of dwellings) will be expected to make on site affordable housing provision in accordance with Policy HG3.

9.24 In order to maximise affordable housing delivery there is an objective to include all residential development in the affordable housing contribution process, thereby capturing a significant proportion of developments that would otherwise be exempt, without threatening viability or reducing housing delivery. Viability evidence[4] shows that a 5% equivalent on site contribution in Yeovil and the Market Towns and 10% on site equivalent contribution in Rural Centres and Rural Settlements is viable in addition to the relevant standard Community Infrastructure Levy contribution. Affordable housing provision is currently outside CIL regulations and therefore the requirement to seek a financial contribution from small sites (1-5 dwellings) is under Section 106 as a commuted sum[5]. Affordable housing is exempt in current regulations from the limit for pooling financial contributions from more than 5 sites.

Policy HG3: Provision of Affordable Housing

Planning permission for the erection of new dwellings will be permitted provided that, where it is viable to do so, the scheme provides affordable housing in accordance with the following:

Settlement Affordable housing target Threshold OR Hectares (irrespective of number of dwellings)
Yeovil Urban Extension
Primary Market Towns
Local Market Towns
Rural Centres
Rural Settlements*


 6 dwellings


  • All affordable housing contributions shall enable the provision of the number of affordable dwellings without the need for public subsidy;
  • Affordable housing will be provided on the application site except where there are good planning grounds that indicate that the provision of affordable housing would not be appropriate on that site. It is preferable in such circumstances that a financial or other contribution should be made towards the provision of affordable housing on another site in the settlement or nearby settlement;
  • Where the above level of affordable housing provision renders a site unviable a reduction of provision will be accepted on the basis of an 'open book' submission in accordance with Policy SS6 and the Planning Obligations Protocol 2006.
* Threshold only applies to those developments considered to be acceptable by nature of their sustainability as permitted by Policy SS2.
Policy HG4: Provision of Affordable Housing - Sites of 1-5 Dwellings

Small sites below the threshold for a full affordable housing contribution will be expected, where it is viable to do so, to pay a commuted sum equivalent to a percentage of affordable housing provision on site as set out below. This will be over and above the relevant standard CIL contribution.

Settlement Percentage equivalent of affordable housing provision on site Number of dwellings
Yeovil, Primary Market Towns and Local Market Towns
Rural Centres and Rural Settlements 10% 1-5

9.25 Affordable housing will be delivered within the framework of this Local Plan and the Council's Housing Strategy. Developer and RPs will be expected to deliver the affordable housing requirements through the planning process, with the Council securing appropriate affordable housing through legal agreements.

9.26 Affordable rent is the model which the Government expects RPs to deliver when receiving Homes and Communities Agency funding (HCA) for the period to 2015. Rents are set at 'up to 80%' of the market rent and so are usually higher than social rent, and subject to a different rent setting formula. National planning policy guidance[6] defines 'affordable rent' as separate from 'intermediate rent' but in reality it is an intermediate product.

9.27 The number type and tenure of affordable housing will be negotiated on a site by site basis informed by the SHMA, contemporary information from the housing register and taking into account local imbalances. The number of units to be provided should be delivered at nil public subsidy as there is no guarantee that any form of public funding will be available for development projects. Developers and landowners should therefore, in the first instance, calculate the cost of contributions to affordable housing on the basis that public subsidy will not be available[7]. Factors such as local need, market and site conditions, and site-specific development costs will be taken into account and an 'open-book' approach will be taken to negotiation where necessary.

9.28 The most up to date viability assessment will clearly present key evidence in any negotiation on site viability. To ensure that changing economic circumstances are taken into account the viability assessment/s will be updated approximately every 3 years.

9.29 All affordable housing produced through planning obligations is required to meet prevailing minimum space standards as determined by the Homes and Communities Agency (or any successor organisation) or any other standard subsequently adopted by the Council.

9.30 Government guidance[8] recognises that when seeking affordable housing contributions the provision should be made on the application site. This is in order to ensure that developments provide a reasonable mix and balance of housing types and sizes. However, there may be particular circumstances where the Council and developer agree, where it has been adequately justified, that a commutation scheme may be acceptable, either by way of off-site provision or a financial contribution in lieu of on-site provision (this should be broadly of an equivalent value). Off site provision should be made in accordance with the settlement strategy set out in this document and arrangements must be made to secure the transfer of the site to a RP or other affordable housing provider at a value that ensures the delivery of affordable housing.

9.31 In cases where 'open book' valuations point to a reduced affordable housing provision on site publicly funded options may be used if available and if considered appropriate to restore affordable housing provision on site towards target levels (ie 35% of the total number of dwellings).

9.32 In terms of developability, and for ease of management, affordable housing should be dispersed throughout a development site although small clusters of affordable housing are acceptable in some circumstances.

9.33 The following delivery bodies will be key in implementing Policies HG3 and HG4: 

  • South Somerset District Council;
  • Developers and Landowners;
  • Registered Providers.
Monitoring Indicators Target
Affordable housing completions Delivery of 35% of the total number of dwellings on developments of 6 dwellings and above (or 0.2 ha irrespective of the number of dwellings). The provision of additional affordable housing through commuted sums collected on site of 1-5 dwellings.
Dwelling size, type and tenure of affordable housing The housing mix of new affordable housing should correspond with the requirements as set out in the current Strategic Housing Market Assessment or Successor document or alternatively a Local Housing Needs Assessment.
1. 9 dwellings or less [back]
2. Affordable Housing Threshold Viability Study Annex May 2010 [back]
3. Housing Density discussion paper presented to Planning Management Board (PMB) on 7th June 2011 [back]
4. Small Sites Affordable Housing Financial Contributions Economic Viability Appraisal (2012) - builds upon the Affordable Housing Threshold Viability Study Annex May 2010 [back]
5. At January 2012 5% equates to £20 per sq m and 10% equates to £40 per sq m [back]
6. NPPF March 2012, Annex A: Glossary [back]
7. The SHLVA assumes nil public subsidy [back]
8. NPPF para 50 March 2012 [back]