This is a legacy version of the WELL Building Standard. Please check the latest version here.

Air infiltration management

Indoor air quality and thermal comfort can be compromised by leaks and gaps that break the building’s air barrier. These weak points are not only wasteful but can also lead to conditions conducive to growth of molds and the infiltration of pests or polluted air.

This feature requires testing to check for air leakages in the building envelope. Such tests are often used to optimize a building's energy efficiency and can also be used to maintain indoor air quality and comfort. It also prescribes thermal breaks and water-impervious materials which may be difficult in existing buildings but are best practice in modern construction.

Part 1: Air Leakage Testing

The following is performed after substantial completion and prior to occupancy to ensure the structure is airtight:

a.1 Envelope commissioning in accordance with ASHRAE Guideline 0-2005 and the National Institute of Building Sciences (NIBS) Guideline 3-2012 (for new construction or structural renovation).
b. Detailed plan for action and remediation of unacceptable conditions.
Part 2: Leak Tests for Residences

One of the following methods is used to evaluate the building envelope:

a. Blower door testing.
b. Infrared thermography.
c. Hot-wire anemometer.

Applicability Matrix

Core & Shell New & Existing Buildings New & Existing Interiors
Part 1: Air Leakage Testing O O O
Part 2: Leak Tests for Residences - - -
Commercial Kitchen Education Multifamily Residential Restaurant Retail
Part 1: Air Leakage Testing O O - O O
Part 2: Leak Tests for Residences - - O - -

Verification Methods Matrix

Letters of Assurance Annotated Documents On-Site Checks
Part 1: Air Leakage Testing Commissioning Report
Part 2: Leak Tests for Residences Contractor Leak Test Report

U.S. Green Building Council. LEED v4: Reference Guide for Building Design and Construction. Washington D.C.: U.S. Green Building Council; 2013: 37, 43-44, 541-552, 567, 605, 623, 645-53, 658-61, 682-3, 685-6, 723-4.


LEED v4 BD+C: Enhanced commissioning provides two options for the credit, one of which involves following commissioning processes for the building's thermal envelope in accordance with ASHRAE Guideline 0-2005 and NIBS Guideline 3-2012.