only 26 states are using the latest residential codes or their equivalent, and only 25 states have adopted
the latest and most energy efficient commercial codes.
In addition, many states lack consistent
enforcement and support programs, resulting in a shortfall in energy performance.
The DOE's Building Energy Codes Program has worked for 25 years with the building industry,
state and local governments, public interest groups, and others to improve the design and implementation
of building codes. The program provides information and a comprehensive set of support tools to help
builders, designers, and code officials to upgrade and comply with energy codes. In particular, DOE has
produced widely disseminated software tools to simplify and improve code compliance, and supporting
materials such as a consolidated workbook with prescriptive compliance tables. The National Association
of Home Builders incorporated these tools into their builder manual in early 1996; as a result, these tools
are now widely used by both builders and code officials. The DOE Building Energy Codes Program budget
in recent years has been approximately $8 million, about half of which goes to state agencies.
An estimated 0.15 quads of energy were saved in 1998 and 3.55 MMTC were avoided as a result
of energy code upgrades through 1998
(this represents about 1 percent of the 318 MMTC emitted
from the building sector in 2002). This estimate of past impacts assumes that roughly half of the poten
tial energy savings are actually achieved actual energy performance is not as energy efficient as rated
performance. Even with this conservative assumption, consumers nationwide saved around $1.1 billion in
1998 (1994$) as a result of the adoption and implementation of improved energy codes, equivalent to
about 1 percent of expenditures for space heating and cooling in all buildings. These savings are limited
in part by the slow turnover of the nation's building stock. Savings will grow over time, however, as more
buildings are constructed and more jurisdictions adopt state of the art codes.
Rosenquist and coauthors estimate the nationwide energy savings potential from upgrading resi
dential and commercial building codes in 2010 and again in 2020.
Residential building codes are
modeled in terms of improvements to shell measures such as insulation, glazing, and infiltration that
reduce heating and cooling loads. Commercial building codes are modeled in terms of improved space
heating, air conditioning, and commercial sector lighting.
The result is an estimated cumulative energy
savings of 2.2 quads for residential building codes and 3.0 quads for commercial codes totaling
5.2 quads over the 20 year period or an annual estimated potential savings of 0.26 quads.
estimate assumes complete code compliance combined with some ongoing technology improvements
Towards a Climate Friendly