Executive summary - viability assessment

Standardised Inputs to Viability Assessment

The minimum requirements necessary to be submitted as part of a viability appraisal executive summary include the following parameters:

  • Gross development value
  • Benchmark land value including landowner premium
  • Costs:
    • Build costs
    • Abnormals
    • Site Specific infrastructure
    • Policy requirements (Section 106/Community Infrastructure Levy)
    • Financing (e.g. loans)
    • Professional fees (e.g. marketing, legal, architects, overheads)
    • Contingency
    • Other (Please Detail)
  • Developer return
  • How the viability assessment has informed the planning application
  • Developer contributions compared to policy requirements

Definitions of Content Requirement

Principles for carrying out a viability assessment

Viability assessment is a process of assessing whether a site is financially viable, by looking at whether the value generated by a development is more than the cost of developing it. This includes looking at the key elements of gross development value, costs, land value, landowner premium, and developer return.

National Planning Guidance sets out the government’s recommended approach to viability assessment for planning. The approach supports accountability for communities by enabling them to understand the key inputs to and outcomes of viability assessment.

Any viability assessment should be supported by appropriate available evidence informed by engagement with developers, landowners, and infrastructure and affordable housing providers. Any viability assessment should follow the government’s recommended approach to assessing viability as set out in this National Planning Guidance and be proportionate, simple, transparent and publicly available. Improving transparency of data associated with viability assessment will, over time, improve the data available for future assessment as well as provide more accountability regarding how viability informs decision-making.

In plan making and decision-making viability helps to strike a balance between the aspirations of developers and landowners, in terms of returns against risk, and the aims of the planning system to secure maximum benefits in the public interest through the granting of planning permission.

How should gross development value be defined for the purpose of viability assessment?

Gross development value is an assessment of the value of development. For residential development, this may be total sales and/or capitalised net rental income from developments. Grant and other external sources of funding should be considered. For commercial development broad assessment of value in line with industry practice may be necessary.

For broad area-wide or site typology assessment at the plan making stage, average figures can be used, with adjustment to take into account land use, form, scale, location, rents and yields, disregarding outliers in the data. For housing, historic information about delivery rates can be informative.

For viability assessment of a specific site or development, market evidence (rather than average figures) from the actual site or from existing developments can be used. Any market evidence used should be adjusted to take into account variations in use, form, scale, location, rents and yields, disregarding outliers. Under no circumstances will the price paid for land be a relevant justification for failing to accord with relevant policies in the plan.

How should costs be defined for the purpose of viability assessment?

Assessment of costs should be based on evidence which is reflective of local market conditions. As far as possible, costs should be identified at the plan making stage. Plan makers should identify where costs are unknown and identify where further viability assessment may support a planning application.

Costs include:

  • build costs based on appropriate data, for example that of the Building Cost Information Service
  • abnormal costs, including those associated with treatment for contaminated sites or listed buildings, or costs associated with brownfield, phased or complex sites. These costs should be taken into account when defining benchmark land value
  • site-specific infrastructure costs, which might include access roads, sustainable drainage systems, green infrastructure, connection to utilities and decentralised energy. These costs should be taken into account when defining benchmark land value
  • the total cost of all relevant policy requirements including contributions towards affordable housing and infrastructure, Community Infrastructure Levy charges, and any other relevant policies or standards. These costs should be taken into account when defining benchmark land value
  • general finance costs including those incurred through loans
  • professional, project management, sales, marketing and legal costs incorporating organisational overheads associated with the site. Any professional site fees should also be taken into account when defining benchmark land value
  • explicit reference to project contingency costs should be included in circumstances where scheme specific assessment is deemed necessary, with a justification for contingency relative to project risk and developers return.

How should land value be defined for the purpose of viability assessment?

  • To define land value for any viability assessment, a benchmark land value should be established on the basis of the existing use value (EUV) of the land, plus a premium for the landowner. The premium for the landowner should reflect the minimum return at which it is considered a reasonable landowner would be willing to sell their land. The premium should provide a reasonable incentive, in comparison with other options available, for the landowner to sell land for development while allowing a sufficient contribution to comply with policy requirements. This approach is often called ‘existing use value plus’ (EUV+).
  • In order to establish benchmark land value, plan makers, landowners, developers, infrastructure and affordable housing providers should engage and provide evidence to inform this iterative and collaborative process.

What factors should be considered to establish benchmark land value?

Benchmark land value should:

  • be based upon existing use value
  • allow for a premium to landowners (including equity resulting from those building their own homes)
  • reflect the implications of abnormal costs; site-specific infrastructure costs; and professional site fees and
  • be informed by market evidence including current uses, costs and values wherever possible. Where recent market evidence is used to inform assessment of benchmark land value this evidence should be based on developments which are compliant with policies, including for affordable housing. Where this evidence is not available plan makers and applicants should identify and evidence any adjustments to reflect the cost of policy compliance. This is so that historic benchmark land values of non-policy compliant developments are not used to inflate values over time.

In plan making, the landowner premium should be tested and balanced against emerging policies. In decision-making, the cost implications of all relevant policy requirements, including planning obligations and, where relevant, any Community Infrastructure Levy (CIL) charge should be taken into account.

Where viability assessment is used to inform decision-making under no circumstances will the price paid for land be a relevant justification for failing to accord with relevant policies in the plan. Local authorities can request data on the price paid for land (or the price expected to be paid through an option agreement).

What is meant by existing use value in viability assessment?

Existing use value (EUV) is the first component of calculating benchmark land value. EUV is the value of the land in its existing use together with the right to implement any development for which there are policy compliant extant planning consents, including realistic deemed consents, but without regard to alternative uses. Existing use value is not the price paid and should disregard hope value. Existing use values will vary depending on the type of site and development types. EUV can be established in collaboration between plan makers, developers and landowners by assessing the value of the specific site or type of site using published sources of information such as agricultural or industrial land values, or if appropriate capitalised rental levels at an appropriate yield. Sources of data can include (but are not limited to): land registry records of transactions; real estate licensed software packages; real estate market reports; real estate research; estate agent websites; property auction results; valuation office agency data; public sector estate/property teams’ locally held evidence.

How should the premium to the landowner be defined for viability assessment?

The premium (or the ‘plus’ in EUV+) is the second component of benchmark land value. It is the amount above existing use value (EUV) that goes to the landowner. The premium should provide a reasonable incentive for a landowner to bring forward land for development while allowing a sufficient contribution to comply with policy requirements.

Plan makers should establish a reasonable premium to the landowner for the purpose of assessing the viability of their plan. This will be an iterative process informed by professional judgement and must be based upon the best available evidence informed by cross sector collaboration. For any viability assessment data sources to inform the establishment the landowner premium should include market evidence and can include benchmark land values from other viability assessments. Any data used should reasonably identify any adjustments necessary to reflect the cost of policy compliance (including for affordable housing), or differences in the quality of land, site scale, market performance of different building use types and reasonable expectations of local landowners. Local authorities can request data on the price paid for land (or the price expected to be paid through an option agreement).

Can alternative uses be used in establishing benchmark land value?

For the purpose of viability assessment alternative use value (AUV) refers to the value of land for uses other than its current permitted use, and other than other potential development that requires planning consent, technical consent or unrealistic permitted development with different associated values. AUV of the land may be informative in establishing benchmark land value. If applying alternative uses when establishing benchmark land value these should be limited to those uses which have an existing implementable permission for that use. Where there is no existing implementable permission, plan makers can set out in which circumstances alternative uses can be used. This might include if there is evidence that the alternative use would fully comply with development plan policies, if it can be demonstrated that the alternative use could be implemented on the site in question, if it can be demonstrated there is market demand for that use, and if there is an explanation as to why the alternative use has not been pursued. Where AUV is used this should be supported by evidence of the costs and values of the alternative use to justify the land value. Valuation based on AUV includes the premium to the landowner. If evidence of AUV is being considered the premium to the landowner must not be double counted.

How should a return to developers be defined for the purpose of viability assessment?

Potential risk is accounted for in the assumed return for developers at the plan making stage. It is the role of developers, not plan makers or decision makers, to mitigate these risks. The cost of complying with policy requirements should be accounted for in benchmark land value. Under no circumstances will the price paid for land be relevant justification for failing to accord with relevant policies in the plan.

For the purpose of plan making an assumption of 15-20% of gross development value (GDV) may be considered a suitable return to developers in order to establish the viability of plan policies. Plan makers may choose to apply alternative figures where there is evidence to support this according to the type, scale and risk profile of planned development. A lower figure may be more appropriate in consideration of delivery of affordable housing in circumstances where this guarantees an end sale at a known value and reduces risk. Alternative figures may also be appropriate for different development types.

How does viability assessment apply to the build to rent sector?

The economics of build to rent schemes differ from build for sale as they depend on a long term income stream. For build to rent it is expected that the normal form of affordable housing provision will be affordable private rent. Where plan makers wish to set affordable private rent proportions or discount levels at a level differing from national planning policy and guidance, this can be justified through a viability assessment at the plan making stage. Developers will be expected to comply with build to rent policy requirements.

However, for individual schemes, developers may propose alternatives to the policy, such as variations to the discount and proportions of affordable private rent units across a development, and the ability to review the value of a scheme (rent levels) over the duration of its life. Plan makers can set out in plans where review mechanisms will be used for build to rent schemes.

Scheme level viability assessment may be improved through the inclusion of two sets of figures, one based on a build to rent scheme and another for an alternative build for sale scheme. This would enable authorities to compare and understand the differences, and agree any necessary adjustments to the affordable private rent contribution.


Last Updated on Thursday, January 11, 2024