This article originally appeared in theJuly/August isssue of ARCHITECTURAL LIGHTING magazine.

Ask any lighting designer what today's big issues are, and, after your get an earful about LEDs, you'll probably hear about energy codes and the U.S. Green Building Council's (USGBC) Leadership in Energy and Environmental Design (LEED) ratings systems. Energy codes and other “green” regulations and standards have become a hot topic, and the reasons are twofold. First, these codes and standards are becoming more stringent and more prevalent, so designers are running up against their limits more often. Second, lighting designers and their professional organizations, such as the International Association of Lighting Designers (IALD), have become more involved with code development. But there is also confusion, as energy codes and green building standards are notoriously complex and getting more complicated.

What do lighting professionals need to know? Let's start by looking at energy codes.

In trying to sort out the energy code development process in the U.S., the first thing to remember is that energy codes are generally adopted by states as part of their building codes. There are national model energy codes, but there is no federal energy code. Since 1992, federal legislation has required that states adopt an energy code as stringent as a model energy code (currently ASHRAE/IES 90.1-2004), but there is no mechanism to force states to do so. This means that the U.S. potentially has 50 different energy codes. In practice, most states fall into one of three groups:

  • Those who have adopted some version of the International Energy Conservation Code (IECC): The IECC is revised every three years, so you have to know which version is in effect in a particular state. Some states use the IECC as a model code but then make their own modifications when they adopt it.
  • Those who have their own in-state-developed code: California, Florida, Oregon, and Washington each have their own code and code development process.
  • Those who have no code at all: Eight states have no energy code for commercial buildings, and 10 others have energy codes that are less stringent than required by federal legislation. But in states with no mandatory statewide commercial energy code, there may be a code that applies to public buildings, or something that has been adopted by a local county, city, or municipality.

It is important to determine which version of which code is in effect in a particular state. Fortunately, there are two websites that have comprehensive information on energy code status in each state. The first is available through the Online Code Environment & Advocacy Network ( and the second can be found through the U.S. Department of Energy (DOE)'s Building Energy Codes Program (
There are two model energy codes in the U.S., ANSI/ASHRAE/IES Standard 90.1 and the International Energy Conservation Code (IECC). Both are comprehensive building energy codes, but the IECC has been the code of choice in recent years.

ANSI/ASHRAE/IES Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings, known as “ASHRAE” or “90.1” has its roots in the response to the energy crises of the 1970s. It is developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the Illuminating Engineering Society (IES). Standard 90.1 is the most familiar because it has been around the longest, and because IES and IALD members have been active on the 90.1 lighting subcommittee for decades.

The standard is developed according to ANSI and ASHRAE procedures in an open process centered on committees of experts. In the case of the lighting portion of 90.1, the hard work of developing the standard is overseen by the lighting subcommittee who work constantly on code development, proposing improvements, and organizing the development process. But anyone can propose a change to the standard by contacting the subcommittee, and all proposed changes go out for public review and comment. All comments must be responded to by the relevant subcommittee, with the goal to resolve each comment in a way satisfactory to both the subcommittee and the commenter. The standard is always being worked on in a process known as “continuous maintenance,” with complete new versions published every three years. The next version, 90.1-2010 is expected this fall.

The IECC is the relative newcomer. First issued in 1998, it is developed by the International Code Council (ICC), the organization that develops building codes in the U.S., and has become the code that states are adopting. It is also developed in an open process. Like 90.1, anyone can propose a change to the IECC. But instead of being considered by subcommittees of experts, proposed changes are debated in formal verbal testimony at open hearings, which last about a week and occur once every three years. The results of those hearings (where a committee rules on each proposal) are published, and then written public comments are accepted on the change proposals. Then, about one year after the first hearings, testimony is heard again at the “Final Action” hearings where only those ICC members who are code officials—and who show up at the hearings—vote on each change proposal. Proposals that pass will become revisions to the code. ICC staff then compiles and reconciles the results of the voting on each change proposal and publishes the next version of the IECC. New versions of IECC are issued every three years (but not on the same schedule as 90.1). The next version of IECC, known as IECC-2012 is in development and slated for publication in April 2011.

To understand the IECC, it's important to know that the IECC references 90.1 as an alternate compliance path. This means that if IECC is the adopted code, you can use IECC or 90.1. Originally, IECC was regarded as an easy-to-use code for basic projects, but if you had a complex or unique project that was not well addressed by the provisions of the IECC, you could use the more sophisticated (and complicated) Standard 90.1. The IECC lighting section was originally based on 90.1 and still contains some identical language. But as new versions of the IECC have been developed, new language and provisions have been added and the IECC has diverged from 90.1 and has grown more complex.

Before IECC-2009, you could mix and match the codes by discipline. For example, a lighting designer on a project could use 90.1, but the mechanical engineer could use IECC. With the 2009 version, you must choose one code for the entire building. Depending on which version of the IECC is in effect in that state determines whether the lighting designer has the flexibility to choose which energy code he or she will follow. Lighting designers who work nationwide need to be conversant in several versions of each of the two codes.

The IECC is the code that states are adopting when they update their energy code, or when they adopt a code for the first time. This is probably because the IECC is produced by the ICC, the source of other building codes used in the U.S. As of July 1, 31 states have adopted some version of the IECC. Only five states use a version of 90.1 by itself.

However, 90.1 will most likely remain significant for several reasons. First, the 1992 federal Energy Policy Act established it as the standard that the Department of Energy must use to evaluate state codes. If the code is not efficient enough, a state is required to adopt an equally stringent code within two years. (Although there is currently no way to enforce this.) Second, 90.1 is the energy performance standard used by LEED, and most LEED project must follow 90.1. Third, the work of the 90.1 committees and the addenda review and commenting process are an effective and valuable code development engine where new ideas are tested and refined. This is directly supported by the DOE with resources to perform modeling and analysis. For anyone interested in a more in-depth explanation of the energy code development and adoption process, read the Department of Energy's “Building Energy Codes 101,” which can be found at:

So what should architects and lighting designers expect to find in the forthcoming 90.1-2010 and IECC-2012? Because the 90.1-2010 development period came to a close in June and the final published version is expected soon, it is possible to list changes to 90.1 with some confidence. Most notable will be significant changes in lighting power allowances. The modeling used to determine the lighting power allowances for each building and space type was reviewed and revised to reflect current technology and design practice. Mainly because of improvements in light-source efficacy, such as in super T8 and ceramic metal halide, most lighting power allowances are going down.

But the allowances for a few space types are going up; the analysis showed that the power allowances had been incorrectly set too low. According to recent modeling performed by the Pacific Northwest National Laboratory for the DOE, buildings designed to the 90.1-2010 standard will use 30 percent less energy overall than buildings designed to the 2004 standard. Here are some lighting-related changes to expect:

  • Interior lighting power allowances revised (mostly down, some up). Additional allowances for high room-cavity ratios (tall, skinny spaces)
  • Separate lighting power allowances for exterior Lighting Zones 0 through 4. Projects in lower density, less developed areas get less.
  • Reduced lighting power allowances for retail displays • Manual-on (no auto-on) in many spaces
  • Control factors—additional power allowance as an incentive to use advanced controls
  • Bi-level switching
  • Stairwell occupancy control
  • Hotel room master switch
  • Exterior “after hours” control
  • Skylights required in some large spaces.
  • Window-to-wall ratio (WWR) reduced to 30 percent in the prescriptive method. A 40 percent WWR will be allowed in some climate zones if there are daylight responsive controls and the building is the right shape (long and skinny or with light wells).

Because the final action hearings for IECC-2012 do not occur until October, it is more difficult to predict what that code will look like. Based on the published proposals, however, expect a major rewrite of the entire document. This includes large chunks of the lighting section such as the lighting power allowance tables. Expect reduced lighting power allowances, and the addition of a space-by-space method for determining lighting power density.

Another concept that has been proposed is “Additional Efficiency Package Options.” To comply, this means a project will have to pick one option from a menu of energy-efficiency provisions such as more efficient mechanical equipment, on-site renewable energy, or reduced lighting power allowances. Here's a list of likely changes:

  • Lower lighting power allowances
  • Addition of the space-by-space method
  • Occupancy sensors required in some space types
  • Hotel room master switch
  • Separate metering of lighting, HVAC, and plug loads
  • Additional efficiency package options
  • Skylights required in some large spaces
  • WWR reduced to 30 percent in prescriptive method

It is important to remember that when a new version of a model code is published, it is not code until a state adopts the new version. Just because a state uses IECC does not mean that they automatically use the newest version. So far, the current version of IECC (IECC-2009, published in Jan. 2009) has been adopted by only nine states.
With the push for the architecture, engineering, design, and construction communities to reduce carbon footprints by significant amounts over the next 25 years, several trends are under way that will affect lighting regulation. The first is increased code efficiency. There is a big push from the DOE to revise the codes so that buildings will have to use significantly less energy than if they were built under previous versions. The targets for building energy performance are as follows:

U.S. federal goals for energy codes (compared to 90.1-2004) for total building energy:

  • 30 percent reduction by 2012
  • 50 percent reduction by 2017
  • 55 percent reduction by 2020
  • 60 percent reduction by 2023
  • 65 percent reduction by 2026
  • 70 percent reduction by 2029
  • 75 percent reduction by 2032
  • Zero Net Energy reduction by an unknown date

The second trend is less lighting “power allowance lag.” Lighting power density limits are developed to limit the maximum connected lighting load using the most efficacious light-source technology that is appropriate, without sacrificing lighting quality. In the past, the lighting power allowances have lagged behind light-source technology, leaving the designer with some cushion. Prior to 90.1-2004's release, it was easy to design lighting without worrying about bumping into code limits. This was because codes had not yet caught up with energy-efficient technologies and design practices.
Starting with 90.1-2004, lighting power allowances were reduced significantly, and you had to pay more attention to the limits. But it's still pretty easy to produce quality lighting design without much additional effort. The lighting power allowances that will be in 90.1-2010 are based on using high-performance T8 and ceramic metal-halide sources wherever appropriate. Quality lighting will be possible, but it will require extra effort and very careful design choices and light-source selection. IECC-2012 lighting power allowances will be even more stringent. Designers will have to be very careful with their use of energy in order to meet code. Expertise in lighting design will require a deep knowledge of code requirements, and the skill to get the most out of limited power budgets.

The third trend is less “adoption lag.” Getting states to adopt the latest code is easier said than done. Currently, only 10 states have adopted the most recent standard, IECC-2009 or 90.1-2007. Ten states have either no statewide energy code at all, or are using standards older than 90.1-1999. The remaining states use something in between the two. This lag is typical, but I expect that its length will decrease, given the global push to reduce energy consumption and greenhouse gas emissions. Often it can take states years to get through the process of adopting new energy codes. But if more states follow the recent example of Massachusetts, then code lag adoption time will be very short in the future.

Last year, Massachusetts not only adopted IECC-2009 but wrote into law that newer versions of the IECC will automatically become code soon after publication. Also, if a federal energy bill gets through Congress it is likely to have in it financial carrots for states who adopt and enforce stringent energy codes (and sticks for states who don't). Every state, in accepting money from the American Recovery and Reinvestment Act, has certified its intent to adopt a building energy code that meets or exceeds the requirements of 90.1-2007, although it is not clear if this will be enforced.

The fourth trend is outcome-based codes. From the design professional's point of view, the ideal energy code would tell us what the results need to be, and let us figure out how to get there. For example, don't tell us how much connected load we can have for lighting, or what type of HVAC equipment we need to use, just tell us how much energy our building can use and let us figure out how to get there. Of course this is easier said than done, but the code development community is starting to investigate how this could be accomplished in practical, usable, and effective ways.

The promise for designers is flexibility. But with that freedom would come the need for a truly integrated design process, expertise in building-energy-modeling software, and, for the lighting designer, the capability to design sophisticated lighting control systems. Once you establish a limit for how much energy a building can use, regulators could start requiring building owners to certify actual energy usage, instead of merely certifying that the building should perform to code based on its design. If codes start to regulate actual performance, design professionals will have to grapple with the professional liability issues. Can we be held responsible for the energy performance of our building design when we are not responsible for its operation?

The final trend is to go beyond code programs. Some local governments, businesses, and institutions understand that energy codes only set a minimum baseline for acceptable performance. They desire tools to push their community's energy use and carbon footprints even lower. Expect more better-than-code standards such as the Massachusetts Stretch Code. This is an appendix to the Massachusetts energy code that individual municipalities can adopt for their jurisdictions. It applies more stringent provisions on top of the energy code.

Anticipate increased energy performance requirements in green building ratings systems such as LEED and the Collaborative for High Performance Schools. And then there are the green building codes in development, which we will discuss next issue.

Glenn Heinmiller, IALD, is a principal at the architectural lighting design firm Lam Partners, based in Cambridge, Mass., and is the chair of the energy and sustainability committee of the International Association of Lighting Designers.

This article originally appeared in the July/August isssue of ARCHITECTURAL LIGHTING magazine. Part Two is available online here and appears in the September/October issue of ARCHITECTURAL LIGHTING.