Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Analysis of the NIST Commercial and Institutional Building Envelope Leakage Database



Steven J. Emmerich, Andrew K. Persily


In 1998, NIST published a review of commercial and institutional building airtightness data that found significant levels of air leakage and debunked the “myth” of the airtight commercial building (Persily 1998). Since then, NIST has expanded and maintained a database of whole building envelope leakage measurements of U.S. commercial and institutional buildings. In addition to building leakage values collected from research publications, low-energy building programs and private pressurization testing firms, the database includes basic building characteristics such as year built, building type, floor area, number of stories, location, and wall construction type for many of the buildings. The purpose of the database is to establish default values for building simulation, to estimate the energy savings potential of airtightness requirements in standards and codes, and to identify opportunities for additional improvements in building airtightness performance. This paper presents an update of the currently available airtightness data from the NIST commercial building air leakage database. The U.S. commercial building envelope leakage database now contains data for almost 350 buildings including more than 50 constructed in the past decade. The data were analysed to determine the impact on airtightness of factors such as building type and height. Significantly, recent additions to the database include numerous buildings constructed to meet the specifications of sustainable or high performance building programs such as the U.S. Green Building Council’s LEED rating system as well as buildings designed and constructed with air barriers, both of which tend to correlate with lower building envelope air leakage.
Air Infiltration and Ventilation Centre


Airtightness, air barrier, fan pressurization test, infiltration, sustainable buildings


Emmerich, S. and Persily, A. (2013), Analysis of the NIST Commercial and Institutional Building Envelope Leakage Database, Air Infiltration and Ventilation Centre, [online], (Accessed April 18, 2024)
Created May 22, 2013, Updated February 19, 2017