The proposal adopts a risk-based assessment which distinguishes between Greater London (Significant Risk) and the rest of England (Moderate Risk). Depending on the fabric elements (glazing exposed to the outside) and the provision of cross ventilation, the ability to limit solar gains and the removal of excess heat must be proven using the simplified methodology. A simplified assessment means that some design restrictions would be applied, or alternatively compliance can be demonstrated through dynamic simulation.

AES Sustainability Consultants have looked at practical examples of what the implications of the simplified method could look like. Outside of London, we do not anticipate any major problems meeting the maximum glazed area. The challenge for the designer will rather lie in the provision of sufficient free area for natural ventilation.

We welcome the proposed new method as it will provide an incentive to address maximum glazing and minimum free area early in the design process but also allow the flexibility to go to dynamic simulation assessment. Please click here for further information on the consultation response.