West Suffolk Five Year Housing Land Supply report (5YHLS) 2022 consultation

West Suffolk Five Year Housing Land Supply draft report 2022

4. The housing supply

4.1. The National Planning Policy Framework (NPPF) requires local planning authorities to identify a supply of specific deliverable sites, which are then measured against the housing requirement.

4.2. For sites to be considered deliverable, National Planning Policy Framework (2021) states they should be:

To be considered deliverable, sites for housing should be available now, offer a suitable location for development now, and be achievable with a realistic prospect that housing will be delivered on the site within 5 years. In particular:

a) sites which do not involve major development and have planning permission, and all sites with detailed planning permission should be considered deliverable until permission expires, unless there is clear evidence that homes will not be delivered within 5 years (for example because they are no longer viable, there is no longer a demand for the type of units or sites have long term phasing plans).

b) where a site has outline planning permission for major development, has been allocated in a development plan, has a grant of permission in principle, or is identified on a brownfield register, it should only be considered deliverable where there is clear evidence that housing completions will begin on site within 5 years. (NPPF 2021 Annex 2).

4.3. The Planning Practice Guidance (PPG): Housing Supply and Delivery gives further advice at para 007 on preparation of five-year housing land supply (5YHLS) reports and states ‘In order to demonstrate five years’ worth of deliverable housing sites, robust, up to date evidence needs to be available to support the preparation of strategic policies and planning decisions. Annex 2 of the National Planning Policy Framework defines a deliverable site, and described as category a. or b. sites. As well as sites which are considered to be deliverable in principle (category a. sites), this definition also sets out the sites which would require further evidence to be considered deliverable (category b. sites), namely those which:

  • Have outline planning permission for major development.
  • Are allocated in a development plan.
  • Have a grant of permission in principle.
  • Are identified on a brownfield register.

4.4. Such evidence, to demonstrate deliverability, may include:

  • Current planning status – for example, on larger scale sites with outline or hybrid permission how much progress has been made towards approving reserved matters, or whether these link to a planning performance agreement that sets out the timescale for approval of reserved matters applications and discharge of conditions.
  • Firm progress being made towards the submission of an application – for example, a written agreement between the local planning authority and the site developer(s) which confirms the developers’ delivery intentions and anticipated start and build-out rates.
  • Firm progress with site assessment work.
  • Clear relevant information about site viability, ownership constraints or infrastructure provision, such as successful participation in bids for large-scale infrastructure funding or other similar projects.

4.5. Planning Practice Guidance (PPG) para 014 provides advice on what information should be included and made publicly available. Detailed information is set out in the appendices to this report. The authority monitoring report monitors annual net housing completions and affordable completions, alongside other housing indicators.

4.6. This assessment of supply includes sites with planning permission at 31 March 2022. A housing trajectory is included (appendix 2) illustrating which sites will contribute to the five-year supply. The housing supply is shown as a net figure thereby taking account of any losses (demolitions, change of use etc). Appendix 3 provides a list of large sites (10 or more dwellings) with full planning permission at 31 March 2022 (category a. sites) and provides supporting information. These sites fall within category a. of the definition of deliverable as set out in para 4.2 large sites with planning permission (at 31 March 2022) are included where they have full planning permission and those with outline permission where there are approved reserved matters and there is no evidence indicating they are not deliverable within the five-year period. For some of the larger sites which will be built out over a longer time period, the five-year supply only counts units expected to be completed within the five-year period. Appendix 7 provides a list of small sites with planning permission (at 31 March 2022) which are counted as contributing towards the five-year supply. All site numbers are shown as net gain of units. A lapse rate of five per cent has been applied to these small sites for reasons set out in paragraph 5.17 to 5.18 below.

4.7. All other large sites (category b.) included within the five-year housing land supply (5YHLS) are listed in appendix 4. These sites meet the requirements of category b. of the definition of deliverable as set out in para 4.2 above. These include sites allocated in the three adopted former St Edmundsbury Vision 2031 Local Plans and the former Forest Heath Site Allocations Local Plan (SALP) where they are considered to be achievable in this timeframe. They include sites on the brownfield register. These include sites which have outline or hybrid planning permission or obtained planning permission after 31 March 2022, those currently subject of an undetermined planning application or reserved matters submission where pre-application discussions, preparation of master plan or development brief have taken place and there is evidence to support their delivery. Some strategic sites contribute provision within the five-year period with the remainder of the units being built out over a longer time period.

4.8. In addition to site identified in this report, there a number of emerging sites, including those allocated in local plan and those with outline planning permission, which have not been included within the supply, these are listed in appendix 11. However at least some are likely to feature in the later part of the five-year period and will further boost the supply moving forward. In accordance with national guidance, they have not been included as contributing to this five-year housing supply.

4.9. Sites with permission in principle or on the brownfield register (appendix 5) which are considered deliverable in the five-year period, already appear elsewhere in the appendices as category a. or b. sites (appendices 3 and 4).

4.10. The planning practice guidance (PPG) states that a contribution of other forms of accommodation including older person housing and student housing can count towards the supply. The contribution is based on an average number of students or adults living in a student accommodation or household using published census data. The sites contributing to the supply, after applying the ratio of 1.5 are listed in appendix 8 and where there is evidence of deliverability they are included within the housing trajectory.

Type of site contributing to the supply in West Suffolk

Contributing to supply in five-year period (net gain)

Large site with planning permission (category a)


Small sites with planning permission (after applying five per cent lapse rate)


Other large sites (category b)


Student accommodation and older person housing contribution (after applying ratio 1.5)


Total identified supply of sites


Information obtained to inform the trajectory

4.11. In order to inform the preparation of the five-year housing land supply (5YHLS) report, the previous five-year housing land supply trajectory was used as a baseline. The council had written to landowners, site promoters and developers seeking information to inform the assessment of anticipated completion of units on each site with an extant planning permission and some allocated sites. A copy of the letter can be found at appendix 1 and statements of common ground for some of the strategic sites at appendix 9.

Assumptions and benchmarks

4.12. The National Planning Policy Framework (NPPF) asks local planning authorities (LPAs) to establish assumptions and benchmarks for lead in times, build out rates and lapse rates based on local circumstances. West Suffolk Council commissioned Turleys to undertake a study into housing delivery which would inform preparation of a housing delivery plan, five-year housing land supply (5YHLS) and any action plans. The study published in March 2019, sits alongside this report as supporting evidence, in particular on built out rates, lead in times and lapse rates. The keys findings on these matters along with local evidence gathered since are summarised below.

4.13. Build out rates – the study show average build out rates in West Suffolk based on historic data of large site delivery (2012 to 2018) range between eight to 60 dwellings per annum across a range of site sizes. The maximum number of homes built in a single year over this period on a large site was 112 dwellings.

4.14. Build out rates can vary on a site-by-site basis, so the average and peak build out should be used as a guide. The following factors can affect rates of build out; differences between greenfield and brownfield sites, the type of the development such as new build or change of use, the localised market, tenure, infrastructure required, whether the scheme includes affordable housing, whether there is more than one house builder on site and how many outlets on site at one time.

4.15. Turleys report which was completed in 2019 does not capture more recent building rate activity at the strategic sites of Marham Park and Moreton Hall, Bury St Edmunds and north-west Haverhill. Further monitoring of the implementation of these sites has had an impact upon both average and peak build out rates across West Suffolk. In the monitoring year 2018 to 2019 at Marham Park delivery rate was 138 dwellings per annum (dpa), in 2019 to 2020 it was 215dpa, in 2020 to 2021 it was 149dpa and in 2021 to 2022 it was 172dpa. Marham Park is being built out by a number of developers, Countryside Properties PLC, Bloor Homes, David Wilson Homes, Bellway and Orbit, leading to much higher rates of delivery on the site than has previously been seen in the district. For the Moreton Hall site delivery rates for these same years were 66dpa, 59dpa, 58dpa, and 61dpa respectively. North-west Haverhill strategic site delivered 67dpa in 2019 to 2020, 89dpa in 2020 2021 and 40dpa in 2021 to 2022. We have learnt from the three years of data since the Turleys report was prepared that build out rates have far exceeded the previous highest peak of 112 and now stands at 215dpa. Delivery rates will continue to be monitored and reviewed and these will inform future trajectory planning.

4.16. Lead in times – this covers the period from the initial site promotion through to completion of the first home on site. There are many factors that can influence the time taken, such as market conditions, the promoter’s financial position, market considerations and specific planning challenges. Site size can influence the lead in times, with smaller sites generally taking less time. The Turleys study shows average lead in times in West Suffolk for large sites increases with site size ranging from three to six years for sites of more than 100 dwellings and around 15 months for sites below 100 dwellings. Since 2012, over half (56 per cent) of all housing sites in West Suffolk were commenced and built out in a single year. The existing assumptions on Turley’s lead in times are considered to remain appropriate and valid.

4.17. Lapse rates – the Turleys report shows from available evidence non-implementation of larger sites with planning permission is rare. In the former Forest Heath area data indicates that no more than five per cent of planning permissions have lapsed in any one of the five years considered (2013 to 2018). Indeed, over the five-year period, an average of 2.3 per cent of sites in the former Forest Heath area annually saw their permissions lapse. Comparable analysis has not previously been monitored for the former St Edmundsbury area, albeit the councils has reviewed this and is monitoring non-implementation in West Suffolk. Whilst there is some evidence of smaller permissions lapsing, the evidence indicates that this remains uncommon, and by definition would not be expected to affect the delivery of a significant number of homes in West Suffolk. It should also be borne in mind that sites which are not considered deliverable in the five-year period have already been removed from the supply and each year as the fie year housing land supply (5YHLS) report is updated the baseline data of sites with extant planning permissions would remove any that may have lapsed.

4.18. Lapse rate across West Suffolk over the monitoring year 2018 to 2019 shows 3.6 per cent of permissions lapsed and for 2019 to 2020 was 3.3 per cent and in 2020 to 2021 was 2.7 per cent. For 2021, 17 planning permissions lapsed out of 619. Only one was for a large site.

4.19. However, the council has still applied a lapse rate of five per cent to small sites for the whole five-year period in recognition that some site could go on to lapse. This applies a consistent approach to that used in the previous 5YHLS report. The lapse rates will continue to be monitored on an annual basis the results of which will inform the application in subsequent 5YHLS reports.

Overall assessment of five-year housing land supply

Five-year deliverable housing supply

April 2022 to March 2027

Annual requirement (including addressing shortfall in five-year period)


Five Year requirement


With buffer five per cent added to the requirement (918 per annum)


Identified supply of sites


Number of years of housing land supply (five per cent buffer)

  5.4 years

4.20. West Suffolk Council has used the Sedgefield approach in measuring the housing supply, which gives a 5.4 year supply of housing land including a five per cent buffer.