ASHRAE 90.1

The American Society of Heating, Refrigerating, and Air-Conditioning publishes technical standards for improving energy efficiency, indoor air quality, building service engineering, and the sustainable development of HVAC&R technology. One of the publications they have is Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings. This is an ANSI standard that has been published by ASHRAE and sponsored by the IES. ASHRAE 90.1, just like most of the society’s material, is updated every three years. The last update for this standard took place in 2019.

The scope of ASHRAE 90.1 revolves around energy efficiency requirements for the design, construction, maintenance, and operation of the following types of buildings:

• New buildings
• New construction on already existing buildings
• New systems installed in existing buildings
• Both new equipment and new building systems that have been specifically identified in the standard as a part of a manufacturing or any other industrial process.

The standard does not apply to single-family homes or multifamily homes that are three stories or less. It does not apply to mobile homes or modular homes. And lastly, ASHRAE 90.1 does not apply to buildings that do not use both electricity or fossil fuel.

Within the standard, there are two different paths an engineer can take to be compliant with ASHRAE 90.1:

• The prescriptive path involves following the minimum requirements put forth by the standard.
• The performance path involves establishing a baseline energy cost budget, or ECB, and then running a building performance simulation on a proposed building design. The ECB here should be equal to or less than the baseline ECB specified to stay in compliance with the standard.

It is important to remember that ASHRAE 90.1 is a guide for building operations. Its purpose is not to push aside any safety, health, or environmental requirements put forth by other standard setting organizations or government agencies like OSHA. In fact, it should work alongside those standards and regulations to create a wholistic approach to safety for the building’s occupants.