Planning policy monitoring

Assessment of housing land supply

Assessment of housing land supply (2024-29)

Introduction

Purpose of report

The National Planning Policy Framework (NPPF) says strategic policies should include a trajectory illustrating the expected rate of housing delivery over the plan period, and all plans should consider whether it is appropriate to set out the anticipated rate of development for specific sites.

The latest iteration of the NPPF (December 2024) states that Local planning authorities should identify and update annually a supply of specific deliverable sites sufficient to provide a minimum of five years’ worth of housing against their housing requirement set out in adopted strategic policies, or against their local housing need where the strategic policies are more than five years old.

The supply of specific deliverable sites should in addition include a buffer (moved forward from later in the plan period) of:

a) 5% to ensure choice and competition in the market for land; or

b) 20% where there has been significant under delivery of housing over the previous three years, to improve the prospect of achieving the planned supply; or

c) From 1 July 2026, for the purposes of decision-making only, 20% where a local planning authority has a housing requirement adopted in the last five years examined against a previous version of this Framework, and whose annual average housing requirement is 80% or less of the most up to date local housing need figure calculated using the standard method set out in national planning practice guidance.

In the absence of a 5-year supply, development plan policies may be treated as out-of-date, making the area susceptible to speculative development pressures.

Local planning authorities should also identify a supply of specific, developable sites or broad locations for growth for the subsequent years 6 to 10 and where possible, for years 11 to 15 of the remaining plan period.

This section outlines the deliverable and developable housing land supply for North Northamptonshire in relation to current housing requirements.

This section relates to the monitoring year 2023/24 and is the fourth report to assess housing land supply on a North Northamptonshire-wide basis as a whole (rather than on the former local planning authority areas that preceded the inception of North Northamptonshire Council) and also against Local Housing Need (LHN) rather than housing requirements set out in the JCS (this is explained further below).

The approach to reporting housing land supply on a North Northamptonshire-wide basis rather than staying with the former local planning authority areas (as some other new unitary councils in the UK do) was agreed at the North Northamptonshire Planning Policy Executive Advisory Panel in June 2021.

The information set out below on housing land supply is also included in the full North Northamptonshire 2023/24 AMR.

Housing target

The North Northamptonshire Joint Core Strategy (JCS) was adopted in July 2016 and remains extant as Part 1 of the Local Plan for North Northamptonshire Council (NNC) while a new plan – the North Northamptonshire Local Plan – is developed. The JCS outlines the level of housing to be planned for over the period 2011-31 and sets this out by the former local authority areas as well as North Northamptonshire as a whole. In accordance with JCS Policy 28, this is as outlined in Table 1 below.

As of July 2021 however, the JCS turned 5 years old and as per national policy (para 78 of the NPPF) this means that the housing requirements within should be superseded by Local Housing Need (LHN). In North Northamptonshire LHN for the 2023/24 period is 1,978 dwellings, which equates to 228 dwellings more than the JCS annual housing requirement. These figures are also set out in Table 1 below. LHN can change annually depending on any changes made by government, usually via adjustment to affordability ratios, and will likely again change when the 2024/25 monitoring year is assessed.

Table 1 – Housing requirements for North Northamptonshire and former LPAs

Identifying the supply of deliverable and developable sites

Existing planning consents do not represent the only source of housing land supply when identifying deliverable or developable sites. As referred to above, the local authority is required to identify 5 years’ worth of deliverable sites and 6 -15 years’ worth of developable sites.

The NPPF defines what is meant by deliverable:

“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 five 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.”

The latest National Planning Practice Guidance (NPPG) (Paragraph: 007 Reference ID: 68-007-20190722) further advises that:

“In order to demonstrate 5 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. As well as sites which are considered to be deliverable in principle, this definition also sets out the sites which would require further evidence to be considered deliverable, namely those which:

• have outline planning permission for major development;
• are allocated in a development plan;
• have a grant of permission in principle; or
• are identified on a brownfield register.

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
  or
• 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.”

The NPPF also defines what is meant by developable:

“To be considered developable, sites should be in a suitable location for housing development with a reasonable prospect that they will be available and could be viably developed at the point envisaged.”

Windfall allowance

The NPPF simply defines windfall sites as not specifically identified in the development plan. They normally comprise previously developed sites that become unexpectedly available. Local planning authorities can make a windfall allowance in the five-year supply if they have compelling evidence that such sites have consistently become available and will continue to provide a reliable source of supply.

As past reviews of housing land supply have demonstrated, windfall development has contributed to the provision of new housing across North Northamptonshire and on this basis provision is made for the continuing contribution of this in the assessment of North Northamptonshire’s housing land supply. However, mindful to avoid double counting of smaller sites with an extant planning permission, this element of supply is only included from year 3 onwards in the 5-year assessment period (2024-29).

Five year supply of deliverable sites

Appropriate buffer

When identifying a five-year supply, the NPPF now requires Local Planning Authorities to include a buffer (moved forward from later in the plan period) to the supply of specific deliverable sites of 5% to ensure choice and competition in the market for land, which may rise to 20% if the circumstances outlined above apply. For the latest HDT assessments (2023) the government calculated these on a North Northamptonshire-wide basis for the second time (as opposed to the four former sovereign councils) of which the authority scored 113% (Housing Delivery Test: 2023 measurement), therefore no buffer needs to be applied to this year’s assessment of housing land supply.

Treatment of past under-provision

The NPPF does not explicitly state which method is preferable when addressing shortfall although Planning Practice Guidance states that ‘The level of deficit or shortfall will need to be calculated from the base date of the adopted plan and should be added to the plan requirements for the next 5-year period (the Sedgefield approach)’. (Paragraph: 31 Reference ID: 68-031-20190722). The former local planning authorities of North Northamptonshire have historically used the Sedgefield approach when it comes to these calculations.

However, given the JCS is now more than 5 years old, the JCS housing requirements are now superseded by LHN and therefore shortfall against the past JCS requirements is no longer taken into account as the standard method for calculating LHN factors this in (past shortfall against the JCS requirement is denoted at Appendix 1 for reference). This is as per NPPG guidance (Paragraph: 031 Reference ID: 68-031-20190722) which states:

“Step 2 of the standard method factors in past under-delivery as part of the affordability ratio, so there is no requirement to specifically address under-delivery separately when establishing the minimum annual local housing need figure.”

Five year period

The Planning Practice Guidance was updated in early 2019 to state that “Sites should be deliverable in years 1 to 5 of the plan period, and subsequently reviewed and their status updated each year in the Authority Monitoring Report and Annual Position Statement (if confirming the 5 year housing land supply)” therefore as of the 2018/19 monitoring year, the former sovereign councils in North Northamptonshire prepared their Housing Land Supply positions by treating the current year as ‘year 1’. However since this, the guidance was updated again in July 2019 where this text was removed, potentially leaving the 5 year assessment period open to interpretation (past joint AMRs have used the approach to not include the current year), albeit text at Paragraph 022 was introduced that states; “To ensure that there is a realistic prospect of achieving the planned level of housing supply, the local planning authority should always add an appropriate buffer, applied to the requirement in the first 5 years (including any shortfall)”. The usage of the word ‘first’ indicating that the assessment should start from ‘year 1’ (i.e, for this AMR the 2023/24 to 2028/29 years are assessed). For clarity, the NPPF does not specify which 5-year period should be calculated and para 78 simply refers to ‘five years’ worth’ of housing.

North Northamptonshire Council: Assessment of housing land supply

Deliverable sites

Table 2 below details the composition of deliverable housing sites identified in North Northamptonshire over the five-year assessment period, broken down by area for illustrative purposes. This information has derived from the housing site schedules and trajectories produced for each area that are published in the AMR 2023/24. The methodology for calculating deliverable housing supply across the different areas varies to reflect local circumstances, however work to standardise approaches is ongoing. As can be seen, the area has an identified housing supply of 11,732 dwellings over the assessment period.

Table 2 – Composition of identified housing supply, 2024-29

Five year supply assessment

Table 3 below outlines the assessment of North Northamptonshire’s housing land supply 2024-29 against LHN. As can be seen North Northamptonshire has 5.65 years housing land supply.

Table 3 – Requirements for North Northamptonshire for the 5-year period 2024-2029 measured against LHN

Appendix 1 – Past shortfall in North Northamptonshire

Table 4 below outlines that over the period 2011-24 21,601 dwellings were built in North Northamptonshire. Compared to the requirements of JCS Table 5 over the same period (1,750 x 13 years = 22,750 dwellings), this represents a shortfall of 1,149 dwellings, however this is no longer considered in the housing land supply calculations when using LHN.

Table 4 – Housing delivery in North Northamptonshire relative to JCS Policy 28, 2011-24

Last updated 16 June 2025