You’ll need to implement an ongoing IAQ plan based on the U.S. Environmental Protection Agency (EPA) document, Building Air Quality: A Guide for Building Owners and Facility Managers, EPA reference number 402-F-91-102, December 1991 (see Resources). This document is long (over 200 pages!) and covers the general IAQ issues in addition to mold that you’ll need to address for your IAQ plan. See the Documentation Toolkit for the IAQ Management Plan Guidelines, which gives specific guidance on sections of the EPA document to pay close attention to.

Some projects already have to limit their RH to 60% or below to meet the requirements of ASHRAE-55 for IEQc7.1. However, ASHRAE-55 has a larger window of acceptable RH levels, and the levels vary depending on temperature and air speed. IEQc10 does not provide the flexibility that ASHRAE-55 does. All projects irrespective of temperature and air speed, must limit RH to 60% or below. ASHRAE-55 also focuses on occupant comfort and does not address unoccupied spaces and times. IEQc10, however, demands that humidity is controlled at all times.

The HVAC system must be able to limit interior relative humidity (RH) to 60% or below during all hours, occupied and unoccupied.

If operational expenses have not been tracked effectively over time, documenting the building’s historical data may be costly because of the amount of staff time required to capture this information. If your building uses an effective accounting management system, however, the cost of documenting this credit will be lower.

If the LEED performance period is less than one year, extrapolate costs based on historical trends so that they represent the best estimate of annualized performance period costs.

The LEED Online credit form requires this data to compare to historical operating costs and determine the simple payback of sustainability initiatives.

Track overall operating costs for the project building over the performance period and record the costs associated with significant sustainability actions taken during the performance period.

Become familiar with the required data and begin tracking cost impacts early in the LEED process. It is much easier to document costs as you go than to investigate costs retroactively.

Work closely with the accounting division of your organization to identify this information. For buildings with relatively detailed records and a willing accounting department, this credit should be very achievable.

Most buildings have this data in some form, but project teams need to compile reliable figures and categorize costs accurately to provide the documentation required by LEED.