Housing land audits: research project

Assessment of housing land audits (HLAs) for consistency and compliance, their potential for standardisation and their role in development plan delivery.

Executive Summary

The Scottish Government instructed Ryden LLP, supported by Brodies LLP, to research Housing Land Audits (HLAs). The project assesses HLAs for consistency and compliance, potential for standardisation and their role in development plan delivery.

HLAs monitor housing completions then are used to programme future house building. They assess the adequacy of the housing land supply against policy requirements and directly inform planning, market and infrastructure decision-making. HLAs thus support site progress through to development delivery, which is an increasing focus within the planning system. Housing Needs and Demand Assessments (HNDAs) identify the required numbers of housing units, while development plans identify the amount of housing land required. The two key functions of HLAs are to demonstrate that a 5-year effective land requirement is continuously met, and to provide a snapshot of available land at any point in time. HLAs should be informative not only for planners, but also for the development industry, infrastructure and other service providers.

The current suite of Housing Land Audits (HLAs) produced by Scottish planning authorities was assessed using a red/ amber/ green approach as is demonstrated in the table at Appendix 3.

The majority of current HLAs provide basic facts around a site’s location, size, capacity, planning status, LDP reference, owner/developer and the historic/projected completions. There are however inconsistencies such as not specifying whether a site is brownfield (previously developed) or greenfield, not identifying the tenure of housing, not specifying types of housing proposed, uncertain treatment of small sites and the availability of mapping. The most significant HLA weaknesses are in:

  • Identifying constraints and how they can be remediated (critical for effectiveness);
  • Clarifying the extent of consultation during the HLA process;
  • Identifying sites removed since the previous HLA.

Figure 1: Housing Completions and projections from 2012 to 2022

Figure 1: Housing Completions and projections from 2012 to 2022

These inconsistencies make it difficult to present an aggregate national HLA. The chart shows HLA completions 2012 to 2016/17 and projections 2017/18 to 2022[1]. There is a 10% annual compound growth in programmed completions from 2016 to above 28,000 units in 2020 and 2021. The components of this rapid growth would require detailed assessment, but could be speculated as continued recovery in the private house building sector, the Scottish Government’s major affordable housing programme, and potentially continuation/ opening-up of sites not built-out in previous periods.

The HLA research included an online questionnaire survey of all Scottish Local Planning Authorities, consultations and a panel review of the emerging research findings.

The survey of planning authorities found that housing completions data is mainly sourced from planning teams, building standards teams, developers/ property/ planning agents, and site visits. This implies that cross-checking of completions data is being undertaken during the HLA process. A small majority of respondents cited resources as a barrier, while some mentioned quality, consistency and access to completions data.

A wide range of approaches and data are used to project future house completions. The large majority use planning data. Just over one-third also canvas developers/ landowners/agents. Other sources include: past completion rates; construction activity; site visits; planning permissions and applications; Council housing and other teams; affordable housing reports; Homes for Scotland advice; marketability assessments; market conditions; professional judgement; online searches; key agencies; previous HLAs; and ‘rule-of-thumb’ guidance. Around one-third then seek further evidence of site status, effectiveness, build programme, sales performance and marketing activity, developer interest (if applicable), delays and any questionable build rates.

Where HLA forecast completions, these are reassessed annually. This reassessment may lead to the programming being adjusted. The decay of programming over time was highlighted, with short term projections difficult and “a significant degree of uncertainty” when programming completions beyond 2-3 years.

Most authorities present their 5-year effective housing land supply (in units) against the 5-year housing supply target, to identify a shortfall or surplus. Three authorities distinguish between the housing land target and the housing delivery programme.

Two-thirds of authorities state that newly approved HNDAs should not immediately inform HLAs; the HLA is simply a monitoring tool. One-third suggested that a new HNDA would allow the planning system to be more responsive to the housing system.

The large majority of respondents report that Local Housing Strategies (LHSs) and Strategic Housing Investment Plans (SHIPs) are used to inform their HLAs; however, three respondents indicated that these should not inform HLAs.

Nearly half of authorities do not differentiate between housing sectors. Most of the balance of respondents differentiate by tenure: private or affordable. Some authorities split out historic completions by tenure, but not the effective land supply, as they do not know who ultimately will deliver the development. Others split sites using either known commitments or a standard affordable housing percentage. Some further split affordable housing into Council or RSL. Some show any affordable housing delivered by a private developer as ‘private’. The Clydeplan authorities further sub-divide affordable housing types. SESplan2 proposes separate targets/ requirements for affordable and market housing tenures, which if adopted would need to flow into HLAs.

The inter-relationships between annual HLAs and LDP action programmes varies. One authority is using full programming of LDP sites and the HLA, while another reports that this integration is underway. A further authority indicates that their HLA and Action Programme are now undertaken by the same team. Integrated housing-and-delivery approaches are however currently the rare exception, and most inform each other to a more or less formal extent. There is a current focus on strengthening these links.

The large majority of (but not all) authorities consult their housing teams, Homes for Scotland and site developers/ promoters. Around half consult RSLs, Scottish Water, education and building control. A quarter or fewer consult with SEPA, the Scottish Government, Transport Scotland or communities. Around half convene working groups to discuss the draft HLA. A similar proportion (mainly the same respondents) issue an email with a link to an HLA website. Consultation challenges reported include lack of internal Council resources and uncertainty over who controls some sites. The main area of challenge however is poor / late / over-optimistic / ‘ongoing dialogue’ responses from some site developers/ owners. The process of consultation through Homes for Scotland was noted as helpful and becoming quicker.

The average time to prepare an HLA is 6-7 months: 2 months data gathering; 1 month analysis and compilation; 2-3 months consultation; and 1 month reporting.

Approximately two-thirds of local planning authorities would like further guidance on the preparation of HLAs. Firm guidance is sought: a standard national process for HLAs and in particular the calculation of a 5-year effective housing land supply including across time periods and the treatment of any shortfalls identified by that calculation. The remaining third are not seeking further HLA guidance.

Guidance is also sought on effectiveness of housing sites where marketability may be the only constraint; marketability and programming in rural areas; analysis and reporting by housing market and/ or local authority areas; differentiating between land supply and housing projections; and best practice in linking HLAs with Action Programmes.

Consultations undertaken with stakeholders and the review panel to support the research identified that consistency across HLAs is a major concern. Definitions, dates and completions data are found to be inconsistent. Looking forward, there is even greater variation across HLAs on whether future completions are based upon past built-out rates, industry standard rates, adjustments for type of owner or developer, and so on. Approaches to infrastructure and thus links to action programmes also vary; these could be improved by identifying the specific actions required to make sites effective.
A suite of national standards was requested around housing tenure, types and delivery. The potential for subjectivity in the process from evidence-based HNDAs to housing land requirements in plans was noted, and a consistent “set of rules” was suggested.

That said, it was felt by consultees that the role of HLAs is well understood, and that sharing of best practice has been increasing recently. It was noted that the next 5-10 years should see the best-researched development pipeline yet, which could be used by a wider range of service providers for their own forward planning. Consultees also suggested that the emerging ‘gatecheck’ could embed a long-term development planning approach, to not only plan for current supply, but also to identify the next potential sites (or policies to select those).

In summary, despite the growing importance of HLAs in the modernised planning system, with its focus on effectiveness and delivery, in a development industry dominated by housing and constrained by infrastructure, the current suite of HLAs across Scotland is not consistently defined, researched, analysed, consulted on, tested, reported or integrated with development planning or delivery. HLA inconsistency creates uncertainty in the planning and development system and the (unacceptable) possibility that applying the HLA methods used by one authority to another area would lead to different planning outcomes. Consistent, reliable housing land and development information is required by the planning system, developers, landowners, infrastructure providers, service providers and communities. This consistency could also assist in reducing delays in producing HLAs and resources expended on disputes.

The table presents options to improve HLAs. The route to implementation of any of these is a matter for Scottish Government. However, the extent of the findings would suggest that some form of planning guidance will be required. If left unguided, HLAs’ roles in delivery could gradually improve through closer working with action programmes, and some inconsistencies may be ironed out. However, fundamental elements such as housing tenures, types, completions and projections will still be undertaken in different ways, potentially undermining any consistent links with delivery, continuing the prospect of disputes, and frustrating any attempts to assemble large market area, regional or national analyses of housing land.

Data and analysis

House types and tenures. HLAs should differentiate between housing types and the tenures of completions using a standard approach. Differentiating between houses and flats should form part of
a standardised approach, while noting that the mix at a site may change in future from that currently consented. If more complex monitoring is pursued for policy reasons – for example private rented,
self-build, accessible and adapted housing – then HLAs should nest these within the main headings.

Completions. A standardised approach around defined house types and tenures should be a priority to minimise delays in producing HLAs and promote a consistent approach. The Scottish Government’s house completions data could form an initial baseline, reconciled to explain any differences.

Projections and programming: Dissemination of best practice beyond the existing Homes for Scotland industry guidance is required. This will require specific analysis and advice using historic performance and a range of adjustments, though it will remain a forecasting exercise subject to error and change. The more sophisticated HLAs linking with Action Programmes are separating out the supply of effective land from the programming of house building (while recognising that these are interdependent).


Subject to creating consistent definitions and format, HLA data should be capable of being stored, linked, aggregated and interrogated in a standard manner. A uniform reporting template is not appropriate for different locations, therefore, standardisation should be around HLA data to create baseline information on types, tenures, completions and projections, as well as anomalies such as the varied treatment of small sites. Report formats may then be more or less detailed and sophisticated, depending upon the requirements of the local authority or market area. Interactive mapping should continue to be encouraged.


HLA information should form part of the GIS planning history held by authorities, tracking sites from proposals, to allocations, consents and development, and linked directly to the Action Programme and the timing of investments to release site constraints. At this stage however from an HLA perspective, there may be a risk in increasing specialisation and integration, when the wider methodological underpinnings of HLAs remain so inconsistent. The data and analysis issues are therefore at least a parallel action to systems integration, if not a precursor.


Consultation is a valued part of the HLA process, for information-gathering and to agree the outcome. Private sector house builder consultation is established, typically via Homes for Scotland. Engagement with the Scottish Federation of Housing Associations to match the Homes for Scotland consultation seems to be essential, particularly given interlocking delivery with market housing and the Scottish Government’s current, major affordable housing programme. Some of the consultations currently undertaken with key agencies and other infrastructure providers may however be replaced by closer integration with Action Programmes. Independently chaired consultation forums may be worthwhile.


The Scottish Government could confirm the renewed purpose of HLAs as moving beyond monitoring reports into integrated elements of development plan delivery. A suite of work is required around HLA data and analysis, programming, consultations, reporting, systems and integration. Some of this can be achieved through dissemination of best practice; other elements are more complex and require research and design of solutions (possibly including software). At the Scottish level, the objective should be a clear and consistent ‘national’ HLA. A formal forum operating over the period 2018-2020 would assist with the standardisation of HLAs in the run-up to planning reform. The areas for consideration could be assessed then included in national planning guidance. A further review and evaluation would be required 2019/ 2020 to establish progress, using this report as a March 2018 baseline.

Future of HLAs

The standardisation of HLAs set out above can help to drive planning reform post-2020. A fully integrated, digitised development planning system - from site proposals through to completed developments - may mean that the future HLA is simply a real-time progress report, which can be commissioned and run as required, layered with market area, sites, completions and Delivery Programme data from digital interfaces. At this future point, the housing land focus could potentially move from intensive data-gathering and analysis, onto planning, monitoring and evaluating outcomes.


Email: Deborah McLean

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