Validation of the climatic zoning defined by ASHRAE standard 169-2013

Climatic zoning has a direct impact on building energy efficiency policies. Currently, most countries adopt simplified weather parameters to define their climatic zoning, with the degree-day method being the most widely used. This widespread use of degree-days has been substantially influenced by the adoption of this indicator by ASHRAE on its climatic zoning, which is a core element for the prescription of requirements for buildings based on their location. However, there is no scientific evidence regarding the agreement between building energy performance and the ASHRAE climatic zones. The objective here was to quantify the mismatch between buildings’ energy performance in each given location and the expected energy performance in the climatic zone they are placed. The study uses a performance-based assessment method relying on building energy simulation and GIS. Climatic zoning performance indicators were calculated based on the energy demand of 52 archetype buildings of the U.S. building stock complying with the ASHRAE Standard 90.1–2013. Results suggest that the stipulated climatic zone misclassifies 10% of the area evaluated, potentially misclassifying highly populated urban areas. These misclassifications have direct impact on the building energy efficiency policies of a given location, which may not be the most adequate for its climate. •Degree-day climatic zoning accuracy was assessed using simulation of 52 archetypes.•Assessment addressed the zoning of three states in the southern east coast of USA.•A performance-based validation was applied to quantify the accuracy of this zoning.•10% of the area under analysis is potentially misclassified, affecting 10 million people.•This potential inaccuracy should be taken into account in the policy-making process.