August 3, 2010
by: Carl Yost

Event: Integration Series 101: Bridging the Roles of Architect and Engineer: 101 Fundamentals of ASHRAE 90.1
Location: Center for Architecture, 07.28.10
Speakers: Michael Waite, PE, CEM, LEED AP — Senior Building Technology Engineer, Simpson Gumpertz & Heger; Fiona Cousins, PE, LEED AP — Principal, Arup
Moderator: Ilana Judah, Intl. Assoc. AIA, OAQ, LEED AP — Director of Sustainability, FXFOWLE Architects
Organizers: AIANY COTE Committee; ASHRAE NY Sustainability Committee

Many designers hesitate to dig too deeply into engineering standards and codes — ASHRAE 90.1, for instance. But as moderator Ilana Judah, Intl. Assoc. AIA, said, “It’s something we could certainly engage with more as architects, in order to ask better questions of our engineers, and to form a more integrated design process.” Furthermore, if technical issues aren’t considered early on, it could lead to costly redesigns down the road.

What is ASHRAE 90.1? This standard determines minimum energy-efficiency guidelines for all buildings (except for residences shorter than four-stories). Many jurisdictions — New York included — have adopted the standard as code. It is developed triennially by a commission of architects, engineers, and product manufacturers, and all proposed updates are subjected to public review.

The standard was born of the 1973 oil crisis, with the first version released in January 1975. Michael Waite, PE, CEM, LEED AP, noted the speediness of its creation: “This is a total of 15 months between the onset of a crisis and the development of a brand new energy efficiency standard — it shows that if you really put your mind to it and the put the effort behind it, you can do big things.” Interestingly, Fiona Cousins, PE, LEED AP, noted that ASHRAE 90.1 was developed in the 1970s to minimize energy costs, not necessarily consumption, which puts the standard at a slight philosophical distance from today’s conception of sustainability. But however it’s measured, given that renewable sources account for only 7% of current-day energy production, energy efficiency remains vitally important.

ASHRAE 90.1 is divided into sections according to building systems: the building envelope, HVAC, and lighting, for example. The way the standard works, most sections have “prescriptive,” “trade-off,” and “performance rated” or “simulation” methods for determining compliance. The prescriptive method (the simplest) lists baseline energy performance criteria for a particular system or assembly — if all areas meet the criteria, the building is compliant. The trade-off method allows diminished performance in one area, as long as it is offset by increased performance in another. For more complex building designs, simulations and computer modeling can be used to determine compliance.

In the future, ASHRAE 90.1 will become more and more stringent — the 2010 edition aims to increase efficiency by 30% over the 2004 standard. The new edition’s scope will expand as well, addressing building operations and maintenance, on-site renewable energy sources, and industrial processes — which will create new challenges for architects.

Carl Yost is the marketing and publicity coordinator for Gabellini Sheppard Associates. He has written for, Architectural Record, and The Architect’s Newspaper, among other publications.


Our website has detected that you are using a browser that will prevent you from accessing certain features. An upgrade is recommended to experience. Use the links below to upgrade your exisiting browser.