Background

ASHRAE Standard 90.1-2004 has been the current energy code reference in the International Building Code (IBC) and the International Energy Conservation Code (IECC). As such, this standard defines code minimums for the classes of constructions covered.

The code has multiple compliance paths – from the simple, prescriptive compliance approach (checklist) to complex building energy simulations (performance-based compliance). When the prescriptive levels change (efficiency levels are increased) a new bar is also established for those seeking to use the more complicated energy simulation tools. The changes are climate zone and building type specific.

The ASHRAE Standard addresses building envelope and system requirements for commercial buildings, residential buildings higher than three stories, and semi-conditioned buildings (warehouses, etc.). It is the nation’s model standard for establishing the energy performance requirements of these building types.

ASHRAE 90.1-2007 – What’s Happening Now?

For the first time in over 19 years, ASHRAE (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) has increased the minimum required prescriptive R-value (resistance to heat flow) for roof and wall insulation levels in Standard 90.1– the national model energy code for commercial buildings.

The above-deck roof insulation requirements previously at R-15 go to R-20 – an increase of 33% – in every climate zone in the U.S. Similar increases were approved for walls. The increased roof and wall insulation values apply to all commercial and high-rise residential buildings covered by Standard 90.1. These changes now become a part of the newest edition of the Standard – 90.1-2007.

Let’s Look at some facts surrounding ASHRAE 90.1:

Much of this information was made possible by the efforts of PIMA, with whom Atlas Roofing Corporation is an active member.  For more information about PIMA initiatives, please visit www.pima.org.