ASHRAE Journal - January 2021 - 6

INDUSTRY NEWS

How CBECS Affects 90.1
ATLANTA-In November, the U.S. Energy Information Ad-

ministration released the first estimates from the 2018
Commercial Buildings Energy Consumption Survey
(CBECS), which provides information about the U.S.
commercial building stock. The data can be used to
quantify the energy reduction impact of the most recent
versions of ANSI/ASHRAE/IES Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings.
Standing Standards Project Committee 90.1 members
Don Brundage, P.E., Member ASHRAE, chair of SSPC
90.1; Richard Lord, Fellow ASHRAE, co-vice chair of
SSPC 90.1; Michael Rosenberg, Fellow ASHRAE; and
Len Sciarra, AIA, Member ASHRAE, discuss how CBECS
affects Standard 90.1.
What is the significance of the most recent CBECS?
CBECS is a very important information source on
energy use and equipment stock in the United States
for nonresidential buildings. It is used in countless
different planning activities related to energy use and
forecasting by many different public and private organizations. CBECS is produced by the Energy Information
Administration, part of the United States Department of
Energy (DOE).
How does CBECS affect Standard 90.1?
SSPC 90.1 uses CBECS data for a variety of purposes,
including as an important data source for the standard's
Progress Indicator. The Progress Indicator measures the
reduction in energy use from one edition of Standard
90.1 to the next one, such as between the 2016 edition and the 2019 edition. Pacific Northwest National
Laboratory (PNNL) uses the Progress Indicator methodology to track the national impact of Standard 90.1
throughout the three-year development cycle and periodically reports the results to SSPC 90.1.
The Progress Indicator applies the requirements of
two different editions of the standard-the new edition
compared to the previous-to a suite of established prototype energy models,1 including 16 building types in the
16 ASHRAE climate zones found in the U.S. The savings
are computed and the results aggregated across building
6

ASHRAE JOURNAL

ashrae.org

JAN UARY 2021

types and climate zones using weighting factors based
on new-building permit data to provide a single national
savings number. The characteristics of buildings in
CBECS inform the configuration of the prototype buildings for areas such as building form, heating sources,
HVAC system types, wall construction and window-towall area.
The DOE is required by federal law (the Energy
Conservation and Production Act [ECPA], as amended)
to issue a determination whether the latest edition of
Standard 90.1 will improve energy efficiency in commercial buildings. DOE has 12 months to publish its
determination in the Federal Register, triggered by each
new edition of the standard. The same federal law then
provides states two years from the publication of the
determination to review and update their energy code,
including demonstration that the state code meets
or exceeds the provisions of the updated edition of
Standard 90.1 (in this case Standard 90.1-2019). PNNL
builds on the Progress Indicator approach to provide the
analysis that serves as the basis for the determination.
In addition to the Progress Indicator and the DOE
determination, CBECS and other data sources are used
to determine the economic justification for new proposals to make sure they are cost-effective.
What do ASHRAE members need to know?
CBECS is a rich information source for existing building construction and equipment. This is important
information for different types of planning and forecasting. The U.S. government provides data for free to anyone who wants to use it.
To explore the 2018 CBECS preliminary results, visit
https://www.eia.gov/consumption/commercial

References

1. DOE. 2020. " Commercial Prototype Building Models. "
https://tinyurl.com/yy7p3jkd

To read more about how CBECS affects 90.1, visit
https://tinyurl.com/yahrw2ze to read the full Q&A.

https://www.eia.gov/consumption/commercial https://www.tinyurl.com/yy7p3jkd https://www.tinyurl.com/yahrw2ze https://www.ashrae.org/

ASHRAE Journal - January 2021

Table of Contents for the Digital Edition of ASHRAE Journal - January 2021