Advanced energy codes lead to major savings
State and local jurisdictions around the country are examining advanced alternatives to the traditional national Model Energy Codes, including ASHRAE 90.1 and the International Energy Conservation Code (IECC).
In 2006 the American Institute for Architects (AIA) developed the “ 2030 Challenge ,” an aggressive energy-efficiency goal that is now being promoted by Architecture 2030. The Challenge calls for a 60% reduction in energy use in existing buildings by 2010, with efficiency ratcheting upward to 2030, when all buildings, residential and commercial, have achieved a zero net energy (ZNE) status. In practical terms, this means a 60% to 80% reduction in the buildings’ energy use coupled with on-site or nearby renewable sources of energy to drop energy use to near or at zero. The 2030 ZNE goal has been adopted by the U.S. Conference of Mayors, a growing number of local jurisdictions and states, as well as the U.S. Green Building Council (USGBC), ASHRAE , AIA, and the Illuminating Engineering Society of North America , among other national trade groups. The Challenge has greatly boosted interest in advanced codes and standards.
In addition, the Energy Independence and Security Act (EISA) of 2007 requires that total energy use in federal buildings be reduced 30% from 2005 levels by 2015. EISA also requires that fossil-fuel energy use—relative to the 2003 level—be reduced 55% by 2010 and eliminated by 2030.
Management and reduction of greenhouse gas emissions from the buildings sector, which consumes 40% of U.S. energy, requires substantially reduced energy use in buildings. Even the latest ASHRAE and IECC standards do not provide efficiency levels that are technically achievable and cost-effective.
Programs like the USGBC LEED or the Green Building Initiative Green Globes are also promoting enhanced standards and codes, since they require higher energy efficiency standards in buildings seeking program certification. These two programs acknowledge that energy-efficiency levels above the national standards are both possible and highly valued in the buildings marketplace.
Given this policy setting, much of the code community and building industry is looking at two quantum levels of improvement to address the climate challenge: (1) A near-term 30% energy use reduction over the conventional national standards noted above, based on off-the-shelf technologies and widely accepted, although little practiced, integrated design strategies; and (2) a medium-term 50% improvement over prevailing national standards, based on anticipated improvements in technologies (e.g., solid-state lighting) and new design, operation, and human factors in the built environment.
Existing national energy standards
There are two major categories of energy codes for commercial buildings: those based on national standards, and those developed by individual states or local jurisdictions. Each state can adopt whatever energy code approach it chooses (see Figure 1). Where state law permits the option for local jurisdictions to exceed the statewide standard, assuming there is one, a variety of energy standards can exist.
Advanced energy codes and standards
A number of existing and proposed energy standards either have been adopted as enforceable code language or are voluntary in nature. It is likely that some of the components and approaches of the voluntary standards may become the basis for advanced codes resulting in approximately 30% to 50% reductions in energy use and cost. The generally assumed base case for measuring codes’ comparative energy savings is ASHRAE 90.1-2004, but the 90.1-2007 standard will be referenced as the energy baseline to be exceeded in LEED 2009, the ASHRAE Standard 189 still in development, and Green Globes.
Although the ASHRAE 90.1%%MDASSML%%2010 goal is a 30% savings level over the 2004 standard, state or local adoption of the 2010 standard would roll out at least two, and more often three or more, years (or not all) after its adoption by ASHRAE.
The New Buildings Institute (NBI) Core Performance platform provides a prescriptive path for retail, office, and schools up to 70,000 sq ft to reduce energy consumption 20% to 30% from the 90.1-2004/IECC standards. NBI expects to have the requirements in Core Performance available in IECC code enforceable language/format in January 2009.
USGBC’s LEED program recognizes Core Performance Requirements and Enhanced Strategies for office, public assembly, retail, and schools under 100,000 sq ft. Projects can achieve up to five credits under New Construction (NC), Energy and Atmosphere (EA): Optimizing Energy Performance, without the building energy modeling requirement.
LEED will also consider projects built to the AEDG Design Guides for NC EA credit without the energy modeling requirement.
Toward 50% reductions and beyond
Some states, like Oregon, are moving rapidly toward statewide advanced building codes, but with a local option in place. In early 2008, Oregon Governor Ted Kulongoski announced the formation of several workgroups to recommend legislation for 2009 that would help achieve the state’s goals toward greenhouse gas reductions.
One of the final recommendations sent to the governor was titled “Increase Energy Code Stringency to Help Achieve Carbon Neutral Energy Homes and Buildings by 2030.” As extensive research has shown, codes provide significant cost-effective energy savings from the buildings sector, which can account for up to 40% of total emissions.
Energy efficiency in commercial construction is one of the most cost-effective measures to achieve greenhouse gas reductions and manage the growing need for electric utilities to meet peak load requirements. These concerns are driving the need for rapid evolution in building energy codes.
Many national, state, and local organizations and governments are developing responses to this need for more energy-efficient buildings. In the near term and in the future, more energy- and cost-efficient building energy code strategies will be available, as an important “tool in the toolbox” to help meet the climate change challenge.
|Special thanks to David Cohan of the Northwest Energy Efficiency Alliance, the primary author of the legislative concept. Additional thanks to all Workgroup members and the Oregon Department of Energy staff who contributed to a successful Workgroup process and product.|
|Jim Edelson is a consultant to non-governmental organizations on energy efficiency and climate policy. Mark Cherniack manages NBI’s Advanced Buildings Program, HVAC, and fault detection and diagnostics work. He has been working in the sustainable energy in the US and in Asia for almost 30 years.|
Major national energy standards platforms
• ASHRAE Standard 90.1-1999/2001/2004/2007; 90.1-2010 to be 30% above 90.1-2004; may include a plug load component
• IECC 2003/2006 + 2007 Supplement; 2009 standard being adopted; residential
• New Buildings Institute Core Performance: currently 20% to 30% above 90.1-2004; 15% above 90.1-2007; plug loads included
• ASHRAE Advanced Energy Design Guides: 30% above 90.1-1999
• Proposed ASHRAE Standard 189:eferences 90.1-2007; includes “green” requirements
• USGBC LEED: references current ASHRAE + 15%; LEED 2009 references 90.1-2007
• Green Globes: references ASHRAE 90.1-2007 + sliding 5% to 15% above 90.1 %%MDASSML%% 2007 + green requirements
• Federal Buildings: 50% total energy reduction by 2015; 55% fossil fuel reduction by 2010, zero fossil fuels by 2030—zero carbon; includes green requirements.