Air conditioning reports and energy performance certificates. It became law on 4 January 2011 for Building Owners and managers to undertake surveys every 5 years on all conditioning systems (be that an office, retail unit or shed) exceeding 12 kW. Such surveys are designed to enhance efficiency, reduce electricity consumption, operating costs and ultimately carbon emissions. As the replacement of refrigerant is now restricted in older systems (as established under F-Gas legislation), there is an additional incentive to improve or replace older systems with more modern energy efficient units.