The planning application related to a former hospital complex at Leybourne Grange near Maidstone. Project and cost management consultants Faithful+Gould acted as expert witnesses and carried out the calculations to demonstrate at appeal how retaining some of the buildings, rather than demolishing them, would contribute to sustainable development.
'Embodied energy' is the energy consumed during extraction, manufacture, transport and assembly of building components. Use of bricks and concrete yields a particularly large CO2 burden. Explains Ian Butterss, who led the Faithful+Gould team, "In theory it is possible to calculate the embodied energy associated with any building although the task is practically impossible when looking at older properties since research would be required to obtain details of brick types, factory locations and other variables. However it is practicable to work out the embodied energy that would be involved in re-constructing an existing building. Work undertaken in association with the Climate Change Levy has helped in setting out accepted average consumption and emission figures for some product types. Our study of the Kent development, therefore, centred on the extra CO2 emissions if the existing properties in question were demolished and new buildings erected."
Whilst, in this instance, the emphasis was on the benefits of retaining a number of existing structures in order to avoid adding to environmental loads through unnecessary construction, new buildings can be assessed in the same way, helping to identify the most appropriate construction materials.
Says Ian Butterss "At present use of embodied energy calculations as part of the planning approval process is extremely rare. However, it seems likely that there will be growing demand, given the emphasis on sustainability in almost every aspect of construction."
The land at Leybourne Grange is ultimately expected to be the site of some 600 homes, with the retained old hospital buildings being converted into apartments.