Which standard specifically designates a specific use building preparation method?

The correct choice is ISO 9971:2015. This standard is significant because it outlines the procedures for determining the airtightness of buildings, focusing specifically on the methods for preparing buildings for testing. It provides detailed guidance on the building preparation process, ensuring that the test results are accurate and reliable.

ISO 9972:2015, while related to airtightness testing, focuses more on the measurement techniques and performance requirements rather than specifying the preparation methods used prior to testing. ASTM E1827 and EN 13829 also cover performance measurement for building airtightness but do not delve into designated preparation methods in the same comprehensive manner as ISO 9971:2015. Understanding the specific context and focus of ISO 9971:2015 is essential for anyone involved in building performance testing and ensures adherence to best practices in test preparation.