An air-handler fan pressurization method can be used to estimate envelope leakage in large or tall buildings. However, because the size of a building's air handling system is designed only to meet heating and cooling demands, there may be many unanticipated problems on the test site. For example, one may not be able to perform the envelope leakage test using the air-handler fan(s) with relatively high pressure differences across the building envelope (e.g. 50-75 Pa). In order to overcome the insufficient pressurization problem faced during the air handler fan pressurization test, a combination of an air-handler and a blower door is proposed and verified by performing a pressurization test in an office building. It was found that the proposed method is feasible for evaluating the overall envelope leakage in large or tall buildings. (C) 2013 Elsevier B.V. All rights reserved.