The Assessment Methodology for Building Energy Rating (AMBER) project will provide a set of guidelines to minimise the performance gap in A-rated buildings, complemented by design best practices and user comfort and wellness recommendations. These guidelines will support compliance policies to ensure that design, construction and operation of A-rated buildings achieve high energy efficiency while supporting high levels of user comfort. To produce these guidelines, BER and sensor data from 100 domestic and 25-40 commercial A-rated buildings will be analyzed utilizing the suite of intelligent building software provided by IES Ltd.