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Viability Assessments for the Replacement Local Development Plan (RLDP)

The Council requires all candidate sites for residential (excluding gypsy and traveller accommodation) and commercial development submitted in accordance with the prescribed minimum site thresholds (and densities) to be accompanied by an initial site viability appraisal. A viability assessment will not be required where a candidate site submission seeks the protection of land to maintain the existing use.



The submission of an initial viability appraisal provides an indication of the likely deliverability of a site as well as the intentions of a site promoter to bring the site forward during the Plan period. For the initial viability assessment, you may want to consider your proposed site against the current policy requirements set out in the adopted LDP and relevant Supplementary Planning Guidance (SPG). However, this should be considered as a starting point for an assessment. The Council is interested in whether the proposed site is viable satisfying broad parameters with sufficient financial headroom to accommodate all of the existing LDP policy requirements.


It is recognised that certainty on the deliverability of a site may not always be definitive until more detailed viability information is known as the Plan progresses. Therefore, the Council may request further information proportionate to the nature and scale of the development proposed in order to enable the site to be assessed in detail as to its suitability for allocation in the Deposit RLDP.


The Council will inform site proposers and ask them for a more detailed viability assessment if applicable. This process is to ensure that sites which progress to RLDP allocation can meet new policy requirements and remain viable and deliverable. There will be a charge at this stage for access to the viability model and staff time for analysis of this information.


The Council recognises some information required to demonstrate viability may be considered by the site promoter as commercially sensitive. However, as stated in the Welsh Government's Development Plans Manual (March 2020), this issue of sensitivity is not a sufficient reason to avoid providing the appropriate evidence (para. 5.96 refers). Each submitted Financial Viability Appraisal (FVA) will not be made publicly available and will be treated as confidential between the Council and the person or organisation that has submitted it. The primary purpose of the FVA is to demonstrate whether or not a development proposal and/or proposed site for allocation is likely to be "viable". Where it may be either necessary or appropriate for information from an FVA to be released as evidence, for example to support a specific site allocation in the Council's RLDP, the Council will discuss with the site promoter the extent to which such information may be released.


Viability Assessment Stages

For an RLDP there are three stages to the viability assessment process:


  • Stage 1: Initial Site Viability Assessment (Candidate Site Stage)

    The initial viability assessment must outline, in a proportionate manner, whether or not the site is viable, taking all the site’s infrastructure needs into consideration. At this stage, the Council needs to establish whether the site proposal is viable satisfying broad parameters with sufficient financial headroom to accommodate all of the LDP policy requirements.  After the Preferred Strategy Stage, further site-specific assessments evaluating the proposed development against the RLDP policies will be conducted.


  • Stage 2: High Level Plan Wide Viability Assessment (Preferred Strategy – Deposit Stage) 

    Information provided at Stage 1 will be used to inform a plan wide high-level viability assessment. Stage 2 of this assessment will inform the development of policies within the RLDP (e.g. affordable housing thresholds).
  • Stage 3: Site Specific Viability Assessment (Preferred Strategy – Deposit Stage) 

    Stage 3 involves site specific assessments on submissions the Council is looking to allocate within the RLDP.  At this stage, the Council will contact site proposers notifying them of the need for such an assessment. This step in the process is required in order to ensure that sites which progress to allocation within the RLDP can satisfy new policy requirements and remain viable and deliverable.


    Please note – At this stage, there will be a charge for access to the viability model and staff time for analysis of the information.


Development Viability Model (DVM)  

The DVM is a 'site-specific' appraisal tool that has been produced to work with Microsoft Excel for Office 365, running on Microsoft Windows and as further detailed within the accompanying User Guide (see below). Each copy of the model that is issued by the Council will be 'locked' to relate to a specific development site. The same copy of the model can, however, be re-used to assess more than one proposed scenario for development of that specific site.


A detailed User Guide has been created explaining how the DVM works; it also sets out the information users are required to input into the relevant cells. Each copy of the DVM incorporates a ‘Quick Guide’ too, this is aimed at those undertaking an assessment of a purely residential development site not significantly in excess of 2 hectares (5 acres).  Furthermore, ‘Help Notes’ reminding users of what to do have been built into the model and are embedded within the worksheets themselves.


Also provided below are links to some ‘how to’ videos on the use of the model. These are provided as another means of helping the user understand how the DVM works in a step-by-step guide.


Use of the DVM during the initial Call for Candidate Sites is free of charge. However, a fee will be charged for the use of the model at Stage 3 for sites where the Council requests additional information. Please contact the LDP Team to request a copy of the DVM. 


Please note – The Council intends to use this model for all viability assessments relating to the RLDP, as part of both the Candidate Site and Preferred Strategy - Deposit Stages. Therefore, in order to ensure consistency we would encourage all site proposers to use this model.


If you have any queries about the DVM, please email the Council’s Planning Policy Team:


1. Introduction 


2. Residential Overview


3. Residential Elements


4. Costs


5. Appraisal and Cashflow