Understanding the viability of development is an important requirement of the planning system.  It is critical to the overall assessment of the deliverability of plans and planning policies. This is particularly important in relation to growth areas and the largest and most strategic sites such as new urban extensions, new communities and garden cities/villages.

Rob Smith, Director at Hyas, has created the Garden City & Large Sites (GCLS) Financial Model to enable practitioners to work through scheme viability via a free to use, open source spreadsheet based financial model.

The GCLS Model is high level financial appraisal tool that can enable viability testing of long term, large scale sites (and in particular Garden City proposals) at an early stage in the planning process. It is an open source model capable of being used by relative non-professionals and without the requirement for specialist software. It is designed for use on large scale schemes with a development period of up to forty years.

The GCLS Model has been created primarily to enable early awareness raising on viability implications of strategic options. It can help support an informed dialogue between Local Authorities, scheme promoters and potentially Central Government at an early stage in decision making. A key aspect of the model is that it is ‘open’ in the sense that all parties can see all data and computations.

More information about the Model, together with related downloads is available on the Resources page.