Skip to main content

Climate Based Daylight Modelling (CBDM)

Good levels of natural daylight are important in the design of new buildings, and Method has been particularly successful in executing Climate Based Daylight Modelling (CBDM) analysis on our ESFA projects. Having invested in new software and a large amount of time, we have a process that works and achieves compliance with the determining target metrics.

Climate-based modelling delivers predictions of the natural light that will enter a building based on its location, building orientation and in addition the building’s composition and configuration.

With some benefits over Daylight Factors, (Daylight Factors are a point in time analysis, CBDM is a year round analysis), CBDM is designed to help reduce energy demand, and balance the amount of daylight received to optimise façade design, reduce glare, etc. CBDM is a more detailed analysis that provides more useful results.

In 2013 the UK Education Funding Agency (EFA) made climate-based daylight modelling a mandatory requirement for the evaluation of designs submitted for the Priority Schools Building Programme (PSBP). New school designs that are submitted to the Priority School Building Programme now need to achieve certain minimum criteria for the spatial Daylight Autonomy (sDA) and Useful Daylight Illuminance (UDI).

CBDM is also used to show compliance with the WELL building standard & BREEAM Hea01; the BCO guidance recommends it as well. The new legislation EN 17037, which is likely to replace BS 8206-2, allows for CBDM rather than Daylight Factor.

For more information please call 01793 822044.