David Goldstein, Energy Program Co-Director, San Francisco
Part of NRDC's Year-End Series Reviewing 2015 Energy Developments
The Paris climate talks gave strong impetus to the world's determination to curtail climate pollution through policies that create jobs and economic growth while simultaneously cutting emissions. While they may be a lower profile solution, improved building codes are a cornerstone of a successful climate policy.
One reason for the paucity of discussion of codes is that climate policy is made on a national level, while in the United States and many other countries, energy codes are adopted and enforced primarily at the state or even local level.
Nevertheless, new energy codes have the potential to save 160 MMTCE
(million metric tons of carbon equivalent) of climate pollution in
America by 2030--some 3 percent of emissions of the entire nation--
merely by adopting model codes that already exist. Adopting the 2015
version of the International Energy Conservation Code (IECC) would
result in emissions savings with an economic benefit of a quarter of a trillion dollars over the next 15 years. These
savings compound over time: by 2050 the savings will be about double
the savings in 2030, just because the codes apply to more and more
buildings that have been constructed since 2015.
Savings will also get much larger for two reasons explored next:
Savings from flexibility to builders
NRDC
actively works with coalitions of businesses and other nonprofits to
raise the bar on energy codes. Figure 1 shows the progress of codes.
Figure 1. progress of model codes in the United States
The IECC code applies most commonly to residential buildings, while the ASHRAE standard
is exclusively for commercial buildings. Both standards are voluntary
models, but all U.S. states are required by law to adopt or consider
them, and some foreign jurisdictions adopt them or modify and adopt them
as well.
Figure 1 demonstrates the accelerating progress we have
made since the 2004-6 codes, which were hardly changed compared to 1975.
From 2006 until 2012, coalitions in support of stronger codes succeeded
in getting a reduction in energy use of some 30 percent.
During
the debate over the code for 2015, NRDC believed that there was still
potential for more savings. By offering home builders something they
really wanted--flexibility and the reduction of administrative
burden--in return for increased savings, NRDC successfully helped to
create an alternative path for homebuilders to comply with the code. The 2015 IECC contains a new tradeoff method that allows a home to meet an Energy Rating Index (ERI), the most prevalent of which is the HERS index.
Using the ERI path to comply with the 2015 code requires savings of at
least 45 percent compared to 2006, but allows for increased flexibility
with how the savings are achieved.
The ERI is like a miles-per-gallon rating for homes,
in which a score of 100 means the home meets the 2006 IECC code and a
score of zero means that home has no net energy consumption. Thus a
score of 60 means an energy savings of 40 percent.
Inclusion of
the ERI is valuable to consumers: it tells the buyer how efficient the
home is and how much money they should expect to spend on utility costs.
The HERS score makes efficiency visible by allowing comparisons between
homes. As about one-third of all new homes sold in 2014 were rated with
a HERS score, there is competition between builders for a lower score.
Thus, even though the tightest codes result in the average home having a
HERS score of about 69, and even though most jurisdictions enforce the
weaker 2009 code, the average HERS score last year was 63, showing that
the existence of HERS scores on a wide basis is causing competition
among builders over how much better than code their efficiency is.
This
year, the 2015 code has been adopted in several states, including
Vermont and Maryland, and is in the process of adoption in several
others. Even in states that did not cleanly adopt the model 2015
IECC building code, we still saw some progress. For example, in Texas,
the largest new homes market in the country, the legislature passed a
law that adopts the same prescriptive check-list of required insulation
levels, etc., as in the 2015 IECC as well as the optional ERI method.
While the Texas code contains ERI scores that are higher (therefore,
weaker) than the 2015 model code, either method of compliance is a
substantial improvement over the 2009 code.
Savings from continual improvement
Most
studies of efficiency potential answer the question of how much we
would save if we used technologies current at the time of the analysis,
but do not assume any improvement in those technologies. But in areas
where we have tried consistently to improve efficiency through
up-to-date policies, we have seen rates of improvement in energy consumption of 6 percent per year or more. The study whose results I cited abovedistinguishes itself by modeling an improvement of 5 percent for every code cycle.
Code cycles occur every three years, so this is a very modest assumption.
As noted above, we have been able to achieve savings of about 15
percent every code cycle since 2006. An improvement rate of 6 percent
per year--which we have achieved in the California energy code since
1975--would yield a 20 percent improvement per triennial cycle. This
would lead to a much larger savings projection, especially for 2050. Other areas where we have been able to achieve continual improvement rates of 6 percent annually are noted in my book, "Invisible Energy: Strategies to Rescue the Economy and Save the Planet."
What's next?
In
advance of the next code cycle beginning in 2018, NRDC is working with a
broad variety of stakeholders both to tighten efficiency requirements
by about 5 to 10 percent and to set minimum requirements for savings
from efficiency alone before accounting for solar generation. Currently,
it is unclear whether the version of the ERI score used in the IECC
counts energy savings from solar.
NRDC supports a middle-ground
proposal that will allow some solar tradeoff but also guarantee a
minimum level of efficiency. While investing in energy efficiency is
ultimately cheaper to the consumer, there are attractive financing
options and tax credits that help reduce the upfront costs to the
builder of solar generation equipment and thus create a non-level
playing field. NRDC fully supports efforts to increase solar power, but
solar must be coupled with appropriate levels of efficiency to be most
effective. This type of limited tradeoff for solar power is already
being used in Vermont and Massachusetts.
Energy Codes in California
So
far we have talked about codes in most states, which rely on national
models. But California maintains its own code, which is usually more
advanced than those of other states. This year the California Energy
Commission adopted code upgrades that will save some 25 percent of
energy use compared to the previous code, following a 2016 update that
itself saves some 25 percent. We are working with the Commission and
with stakeholders to assure that the 2019 California code is consistent
with the state's goal of zero-net-energy homes by 2020 (meaning the
home's total annual energy use is roughly equal to the amount of
renewable energy created onsite).
We are also working
collaboratively with builders to try to harmonize California's HERS
system with the national system. Currently, the California system is
minimally used: builders and retrofitters find it too bureaucratic. Its
outputs do not agree with those of the national system, so that a HERS
80 home in California may use less energy than a HERS 65 in Nevada.
While some advanced features of the California system should be
retained, and perhaps extended to the national system, in other areas
the two systems disagree without any good reason. This is a barrier to
using HERS ratings for consumer transparency in California--a barrier we
hope to eliminate in 2016.
Energy codes are a powerful tool for
cutting emissions and lifting the economy. NRDC plans to begin the next
three-year processes of continually improving energy codes at the
national and state levels and anticipates strong success in 2016 and
beyond. We encourage states and cities to adopt the most current codes
to maximize emissions savings and job creation.
http://www.theenergycollective.com/nrdcswitchboard/2304592/building-energy-codes-2015-foundation-cutting-climate-pollution
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