Stage 2: Assessing sites
Source: gov.uk (2025-11-27)

A draft guide to categorising and assessing sites, including suggested methodologies and information to record to support future examination.

We have published this guidance now so that LPAs can see the direction of travel for the new plan making system. We will review the guidance and make any necessary revisions and updates as the new system is implemented, and related regulations and policy are confirmed.

For plans under the legacy plan-making system

If you are submitting your plan under the legacy system, use the create or update a local plan legacy system guidance (https://www.gov.uk/government/collections/create-or-update-a-local-plan-using-the-legacy-system).

The legacy system covers plans to be adopted under the Planning and Compulsory Purchase Act 2004, excluding the amendments made by the LURA, and The Town and Country Planning (Local Planning) (England) Regulations 2012.

Once you’ve completed stage 1 and identified a sufficient range of potential sites, the next step is to categorise them into different groups (for example, different potential land uses or scales of development).

After you have categorised your sites you can start your assessment and determine their development potential. You will be assessing all sites from Stage 1 including sites submitted through the call for sites and sites identified from other sources (including sites you’ve identified).

Learn more about Stage 1: Identifying sites (https://www.gov.uk/guidance/identifying-sites-for-local-plans-stage-1), Stage 3: Determining your draft allocations (https://www.gov.uk/guidance/determining-your-draft-allocations-for-local-plans-stage-3), or Stage 4: Confirming your draft allocations and recording your decisions (https://www.gov.uk/guidance/confirming-draft-allocations-and-recording-decisions-for-local-plans-stage-4)

Categorising sites

Learn how to sort your sites into different categories.

Aim of this section
- sort sites into categories
- understand how best to categorise sites
Outputs of this section
- a list of sites categorised and ready to assess
The purpose of categorising sites is to:
- give an early indication of the type and amount of different development opportunities available in your area
- signpost early in the process where you may need evidence to support certain types of development opportunities
- help inform your emerging spatial strategy
- allow you to assess similar types of sites consistently
- inform decisions on the type of sites you want to take forward as draft allocations in stage 3
For example, the categorisation process might show that to meet the needs of your area, your strategy may be reliant on one particular type of development, or a handful of sites.

Knowing this early on will help guide how you approach the remaining plan making process. Or it could show that there are opportunities for new settlements or wider urban redevelopments that may need additional site or area specific evidence to support any proposed allocations.

Categorising will help flag those additional evidence requirements early on.

How to categorise sites

How you categorise your sites is up to your planning judgement, taking account of your local context and the types of sites which have come forward through stage 1. There should be a strong rationale behind the type and number of categories you’ve chosen, which you can explain within your evidence. Having too many categories may undermine the purpose of categorising.

When defining categories, consider:
- site location
- proposed uses
- scale of development (using information gathered from Stage 1)
- likely lead-in times for different-size and types of development opportunities
- the different evidential requirements that will be needed to support each category of site
- policy designations (for example, Green Belt or national landscapes)
- development scale vs. likely impact
- The types of development that already exist within your area
Types of site categories that are housing-led might include:
- new settlements
- large scale urban extensions
- larger town centre redevelopment or new urban quarters
- estate regeneration
- smaller or medium scale previously developed land
- smaller or medium scale urban extensions to towns or villages
- town or village infill
For employment-led development, you could categorise sites based on their likely future use, for example:
- offices, leisure and retail
- research, development, and knowledge (including studios and university development)
- industrial
- logistics
- data centres
- employment-led mixed use
Sites can be included in more than one category but avoid double counting a site and its development potential during this stage.

Re-categorising your sites

The category a site falls within may need to change, because of new information gathered through your assessments. For example new evidence may indicate that the original proposals for a site submitted through the call for sites may not represent the most efficient use of land, or include all constraints.

You should be comfortable re-categorising sites as circumstances change. However you will want to confirm your site categories before moving to Stage 3 of the process.

Next steps

Once you have finished categorising, you’re ready to start your site assessment.

Assessing your sites and their development potential

A guide to filter, assess and score your sites, including suggested methodologies and what to record for examination.

Learn more about Stage 1: Identifying sites (https://www.gov.uk/guidance/identifying-sites-for-local-plans-stage-1), Stage 3: Determining your draft allocations (https://www.gov.uk/guidance/determining-your-draft-allocations-for-local-plans-stage-3), or Stage 4: Confirming your draft allocations and recording your decisions (https://www.gov.uk/guidance/confirming-draft-allocations-and-recording-decisions-for-local-plans-stage-4)

Aim of this section
- filter out any sites obviously unsuitable for development
- assess each site for their suitability, availability and achievability for development using your methodology
- estimate development potential of sites
- score each site based on your criteria and local context
- determine the deliverability or developability of sites proposed for housing use
- understand what information to record about sites
Outputs of this section
- a set of suitable, available and achievable sites to take forward to the next stage
During assessment, the first step is to filter out any obviously unsuitable sites, before then applying a methodology to identify sites to take forward as potential candidates for allocation.

Your assessment methodology should focus on determining whether a site is suitable, available and achievable (#assessing-suitability-availability-achievability), as well as its development potential (#estimating-development-potential). We’ll define these terms in more detail later on.

Assessing sites will depend on your local context, so using your planning judgement is important. You should take account of known and new information, including from the call for sites, and any additional evidence you gather through site visits, digital data sources and stakeholder engagement.

The aim is to arrive at consistent and clear decisions to be tested at examination. It’s important you’re able to explain and justify your decisions as part of your evidence for examination. We’ll cover what you should include at examination, and what to do if you do not have enough sites later in the guidance.

Take into consideration the specific accommodation needs of Gypsies and Travellers when considering the suitability of sites for development as part of your duties under the Equality Act 2010 to all groups with protected characteristics.

You should assume that sites that are existing plan allocations or that have planning permission are suitable, available and achievable for development. You do not need to assess these sites unless there is evidence to suggest that circumstances may have changed that would require further assessment.

Filter out any obviously unsuitable sites

The first assessment task is an initial ‘sift’ of your sites. This is to rule out sites where constraints are so significant they are likely to make a site unsuitable for development, and where further detailed assessment of the site’s suitability would not be required.

You should only rule out sites at this stage where you are confident that the presence of those significant constraints would mean development of the site would be wholly inappropriate.

Examples of significant constraints are set out below. You should determine what to take into consideration based on the characteristics of your local area and the extent to which they would make a site unsuitable for development. Make sure you clearly record and justify your choices and reasoning.

Example constraints that may mean a site is considered unsuitable for development could include:
- Detailed Emergency Planning Zones
- Flood Zones 3a and 3b
- Health & Safety Executive Consultation Zones
- Public Safety Zones (such as airports)
Where a site is completely or mostly affected by one or more constraints, you should carefully consider whether that site could be suitable if you applied certain mitigations. Mitigations could include (but are not limited to):
- using only part of the site for development
- only certain land uses or types of development being suitable
- requiring infrastructure or enhancements which would make the site suitable for development
You should also consider if other potential sustainability benefits of developing the site could outweigh the constraints. Where this could be the case you should take these sites forward for further assessment of the suitability of the site.

Following ‘sifting’ you will have a list of sites considered ‘currently unsuitable for development’ that you have sifted out, and a list of ‘potentially suitable’ sites. You will need to include strong rationale in your evidence for any sites you decide to sift out at this stage. It is likely that you will have ruled out very few sites.

Where sites might be suitable with certain mitigations, you should record these along with the suggested mitigation and take them forward into the next step in the process.

Assessing suitability, availability, achievability

After your initial sift, you can start your full assessment of the sites you’ve carried forward as potentially suitable.

This means considering a site’s suitability, availability and achievability. You also need to consider whether the site is likely to be viable, taking into account mitigations that might be required. For sites proposed for housing use, this will then help you decide whether a site is likely to be considered deliverable or developable.

We recommend that sites are assessed by category. This is to help improve consistency in assessment and in decision making.

Suitability

A site can be considered suitable if it would provide an appropriate location for development when considered against:
- relevant constraints and their potential to be mitigated
- opportunities the development of the site could present
The suitability of a site is likely to vary depending on the proposed land use and the extent to which the constraints and potential opportunities affect each site. You should consider national planning policy and any relevant policies in a strategic development strategy for the area. The other factors you take into account will depend on the characteristics of your local area and the matters you want to consider. This could include:
- physical constraints such as land contamination and areas at risk of flooding or coastal change
- environmental constraints and designations such as national landscapes, biodiversity and habitat sites
- access to the highway network
- access to services and facilities
Do not rule out sites because a constraint or designation exists. Assess the implications of the constraint or designation and what impacts it may have on the potential for development of the site. This will help you determine if you should rule out a site because of the constraint or designation, or if it should be carried forward.

Availability

This is assessed on whether there is a reasonable prospect, based on current information , that the site will be available for development at a particular point in time. For example, a site should be considered available if the landowner or promoter has stated they intend to build on the site or sell it for development, and you are reasonably confident there are no known legal or ownership constraints to development.

Where such constraints exist you should consider the potential that they can be overcome and that the site could be considered available in the future.

Matters to consider when assessing a site’s availability could include:
- multiple ownerships with no agreements in place
- unresolved ransom strips
- tenancies
- covenants
You should have information from the evidence gathered so far, including through call for sites, to check the availability of a site. You can also use information from landowners and legal searches, where needed.

Consider the likely timescales for development of sites. You may have gathered information on delivery timescales from the call for sites, however you will want to form your own views on this.

For housing sites you could consider lead-in times for:
- different types and sizes of sites (the period of time it takes from submitting a planning application to when the first home is completed on the site)
- build out rates (the number of homes built per year on the site) on justified assumptions that take account of the form of development
This could include locally-based or national assumptions on delivery. You can also take account of local market knowledge from sources such as local developer forums and panels. This information will also be helpful for determining the likely viability and achievability of a site. You could apply similar principles to sites being assessed for their employment use potential.

For sites proposed for housing, it is recommended you assign each site into a 5 year timescale banding - for example, delivery could start within years 0 to 5 of the likely adoption date of the plan, delivery could start within years 6 to 10, and so on. This will help make it easier to determine if a site is considered deliverable or developable later in the process. You do not need to categorise sites that are considered not available.

Achievability

This is assessed on whether there is a reasonable prospect, based on the information available, that a site is capable of being developed at a particular point in time, including if the site is likely to be viable.

To assess likely achievability, you could undertake an initial high-level review of the viability of the sites using typologies or samples of sites. This is instead of making an assessment for each individual site.

These assessments could split the plan area into a few value areas or typologies which reflect price differences, including:
- likely market attractiveness
- development on previously developed / not-previously developed sites
- rural / urban development
- different sizes and density of development
- more marginally viable schemes
This will help you work out if any particular site typologies are likely to be considered unviable. Any sites with a typology that is unviable should be considered unachievable at this stage.

Your goal is to inform potential trade-offs in sites later in the process. A whole plan viability study at a later stage will check the viability of specific sites and any policy expectations your plan might need to consider.

Assessing achievability and viability is likely to require more of your judgement, taking into account the evidence available and any assumptions that you make. Again, you could use local developer forums and panels to get a better understanding of local market conditions and viability. If you determine a site is unachievable, set out the reasoning for this and the evidence that supports your decision.

Estimating development potential

Development potential (or site capacity) essentially means how much development a site could deliver. The development potential of a site is a significant factor that affects the economic viability of a site and its suitability for a particular use. Estimating development potential is therefore usually best undertaken alongside assessing the suitability, availability, and achievability of a site.

For sites submitted through the call for sites the responder may already have provided information on site capacity, but you will need to form your own view.

Housing

For housing sites development potential will depend on assumptions on how densely developments would be built and other factors like information provided through call for sites, size constraints and other constraints on land and development.

For all sites, proposals should make the most efficient use of the land.

You should think about:
- evidence gathered through the call for sites process
- the net developable area, depending on site type and constraints. You could apply gross-to-net ratios, reflecting that a greater proportion of land is likely to be needed for on-site infrastructure for larger sites
- indicative density multipliers - for example, size and location - based on existing densities, or consideration of what an appropriate density could be in the future
- any relevant adopted or emerging policies - for example, local density standards, national space / car parking standards, design policies, green infrastructure and biodiversity net gain requirements
- commercial viability - the types of development that are likely to be viable in the location
- site-specific opportunity - for example, very accessible urban locations suitable for higher density proposals that meet your local needs
Employment

For employment sites, the land use will be a significant factor in determining development potential. It’s likely that many employment sites will be able to support multiple employment uses relevant to the site’s context. You should assess all relevant site uses for site capacity.

You can use indicative plot ratios to estimate development potential based on the type of expected employment floorspace, or on site-specific evidence gathered from call for site respondents. You can also use employment development market intelligence to inform the ratio of buildings to land.

Sites in multiple categories

Having sites assessed for housing or employment, or a mix of uses is acceptable. But you should be careful not to double count a site and its development potential during this stage.

Scoring your sites

When assessing the suitability, availability and achievability of your sites, compare each site and give them a proportional score. Rather than a quantitative-based approach, you should use a RAG (red, amber, green) scoring method instead.

You should assess each site against the constraints and sustainability considerations that are relevant to your sites and local area.

Score each site’s suitability, availability and achievability as a red, amber or green depending on the impact the constraints have, and how you may mitigate them. To help you assign a score, you should consider each site’s strengths, weaknesses and opportunities.

Suitability - example scoring

Green means the site offers a suitable location for the land use, and any known constraints can be feasibly overcome with mitigation.

Amber means:
- the site offers a potentially suitable location for the land use, but has constraints which may impact development potential, or
- the site needs further assessment before it can be deemed suitable
Red means the site does not offer a suitable development location for the land use or there are known constraints which significantly impact development potential and cannot feasibly be overcome with mitigation.

Availability - example scoring

Green means there is a reasonable prospect the site will be available for development within the time envisioned and there are no known legal or ownership issues.

Amber means:
- the site has legal or ownership issues that are considered capable of being resolved and the site could be available for development within the time envisioned
- the site needs further assessment before it can be deemed available
Red means there is no reasonable prospect that the site could be available for development within the time envisioned.

Achievability - example scoring

Green means there is a reasonable prospect that the site is capable of being developed for the land use within the time envisioned.

Amber means:
- the site’s capability to deliver in the time envisioned is limited and the resolution or the timing of the resolution is unknown, or
- the site needs further assessments of some aspects of its achievability
Red means there is no reasonable prospect that the site could be capable of being developed for the land use within the time envisioned.

Overall final scoring

You should then give each site an overall RAG score (red, amber or green). You may need to compare a number of sites and use your judgement to establish a suitable score. The overall score will give everyone a clear indicator of which sites scored better than others at this time.

Example final scoring

Green means this site is a strong candidate for allocation in your local plan, with few or no constraints that need mitigation.

Amber means this site is currently a candidate for allocation, but has a number of constraints to be mitigated against or further assessment is required.

Red means this site is not currently a candidate for allocation in your local plan (although some red sites may need to be re-considered at later stages, depending on the outcomes of any consultation, examination or further assessment work).

Using this approach to scoring will mean you have followed a clear and logical method to scoring your sites, which helps ensure clarity for inspectors and consistency across assessments. You can use your planning judgement to create an alternative scoring, but you need to justify and explain the approach at gateway reviews and examination.

After scoring, you should only discount sites if you can clearly evidence that they are:
- unsuitable with constraints that you cannot feasibly mitigate
- unavailable or unachievable in the timescales envisioned
It should be clear which sites you will be taking forward at each stage, and which ones you will not. Give short, concise explanations for your scoring decisions. These should make it clear if you have changed your mind about a site during the process, and why you have done this.

Determining if sites proposed for housing use are deliverable or developable

Once you have considered a sites suitability, availability and achievability and given each sites an overall RAG score, you should now be able to determine a sites deliverability or developability. This only applies for sites being proposed for housing use.

The difference between a site being considered deliverable or developable is the time period in which it is likely to come forward for development. Deliverable sites are sites that can come forward for development early in the plan period, whereas developable sites are more likely to come forward later on. Use information on timescales you recorded when assessing a sites availability.

For a housing site to be considered deliverable it should be suitable for development, available now, with at least some development achievable within 5 years of the likely adoption date of the plan.

For a housing site to be considered developable it should be suitable for development, with a reasonable prospect it could be available and achievable at the time envisioned. This would normally mean at least some development could occur at some point in the plan period, after the first five years of the likely adoption date of the plan.

Finishing your Stage 2 assessment

When you have completed your detailed assessment, you should have a list of sites with the following information as a minimum:
- site name or reference
- Land use (existing and proposed)
- site location (this should also be mapped)
- site size
- site categorisation
- The sites development potential - how much could be built on each site
- when it might come forward for development
- a list of constraints to overcome
- any potential mitigations for the constraints
- individual RAG scores for suitability, availability and achievability
- overall RAG score
- justifications for overall score
- for sites proposed for housing use, is the site considered deliverable or developable
- indication of which sites you are taking forward to Stage 3 and which ones you are not, and the reasons why
What to do if you do not have enough sites

If you think you do not have enough sites at the end of your detailed assessment to take forward to stages 3 and 4, there are several steps you can take.

These include:
- reconsidering any sites you ruled out during stage 2, including if those sites could be more appropriate for different land uses to the use they were assessed against (for example a site may have been assessed for its suitability for employment use, however it may be more suitable for residential use)
- re-running the assessment process with different mitigation criteria and local considerations
- revisiting the sources of potential new sites previously considered at stage 1, including running another call for sites, which could be targeted towards particular locations or directions for growth, or types of development
- doing further work to find potential sources of sites not previously identified
- reconsidering assumptions around density and development potential
If you follow these approaches and still do not have enough sites, you should document why this is (https://www.gov.uk/guidance/confirming-draft-allocations-and-recording-decisions-for-local-plans-stage-4) and the steps you took to try and address the shortage.

Next steps

The next part of the sites process is Stage 3: Determining your draft allocations (https://www.gov.uk/guidance/determining-your-draft-allocations-for-local-plans-stage-3).