Credit: Headcase

Although architects who have practiced in both the United States and overseas often delegate compliance with energy codes to engineers, lighting designers, and other specialists, these regulations can be major determinants of design. Professionals familiar with the various code systems find that they differ enough, both over time and among legal jurisdictions, that it behooves all members of a design and construction team to become familiar with applicable codes, overcome compartmentalization, and coordinate compliance. Despite lax or uneven enforcement in some places, energy codes are the indispensable stick accompanying efficiency-incentive carrots, and they have been evolving toward ever-greater stringency.

Energy codes all share the goal of improving performance in lighting, mechanical systems, and other building components. They came about during the 1970s and 1980s after the Organization of the Petroleum Exporting Countries (OPEC) convulsed energy prices worldwide, a series of events that coincided with increased environmental awareness in the industrialized West. Variation in public-sector priorities and in attitudes toward regulation means that different standards have taken on the force of law in different locations. The multiplicity of applicable codes, administered at the state or local level in the U.S. and the national level in Europe (under European Commission oversight), can be confusing even for seasoned firms.

While all energy codes have grown tougher in recent years, what they emphasize and how they are implemented differ on the two sides of the Atlantic. “American codes are typically developed for, and enforced by, building code officials,” says Jack Bailey, partner at One Lux Studio in New York, “and building code officials have a longstanding tradition of not interfering with operations after the certificate of occupancy is issued. So in America, our codes tend to be focused almost exclusively on design and construction of buildings, and then take a very hands-off approach for how the building’s going to be operated.” (New York City’s Department of Buildings, he notes, is a rare exception in this regard—with its regular inspections, audits, and retro-commissioning; application of Greener, Greater Buildings Plan standards to existing structures; and public reporting of large buildings’ Energy Star scores.)

The European approach—which Bailey and others see as more progressive and effective, though more difficult to comply with—focuses on measured building performance. (This system is also used by Australia.) In Europe, buildings are assigned an overall annual allotment of energy use, but officials are agnostic about how the efficient use of energy is achieved, and tradeoffs among different components are common. Post-occupancy enforcement mechanisms also hold facility managers accountable.

Some European nations, influenced in part by wartime experiences, instituted energy codes well ahead of the OPEC crisis: Denmark, for example, first incorporated energy-consumption limits into building codes in 1961. In addition, the term “energy codes” carries a broader meaning in Europe, says code-compliance specialist Ryan Meres of the Institute for Market Transformation, including policies on energy rating and disclosure as well as specific building regulations.

Other countries, Bailey says, copy either the American or the European system—more often the former, since post-occupancy enforcement requires “a much more evolved legal tradition” that is not always available worldwide in some cases even for life safety, let alone energy. Having worked on buildings in the Middle East, Southeast Asia, Europe, and the U.S., and having helped to devise the daylighting component of the new International Green Construction Code (IgCC), Bailey recognizes that post-occupancy evaluation “comes with monstrous complexities for everybody involved,” but regards it as the most responsible approach when feasible.

U.S. Codes: Overlaps, Resistance, and Leapfrogging
The older of the two main code systems in use in the U.S. was developed by ASHRAE, formerly known as the American Society of Heating, Refrigeration, and Air-Conditioning Engineers, in conjunction with the Illuminating Engineering Society of North America (IES), and published originally in 1975. The updated American National Standards Institute (ANSI)/ASHRAE/IES Standard 90.1, started in 2001 and updated every three years since then, addresses specific performance metrics in three main areas: building envelope, mechanical systems, and lighting. But those sectors don’t really “talk” to each other that much says Glenn Heinmiller, principal at Cambridge, Mass.–based Lam Partners and chair of the Energy and Sustainability Committee of the International Association of Lighting Designers (IALD).

Expert committees base the standards on models of energy use by minimally code-compliant buildings prototyped at Pacific Northwest National Laboratory, determining ways to increase efficiencies in each area. Lighting standards are based on lighting power density, a budget for wattage per square foot based on building type, with additional requirements for automatic controls such as occupancy sensors for certain uses. The lighting power density limits have “come down, down, down” over the past decade, Heinmiller says, while mandates for occupancy sensors and daylight-response controls have increased.

The 2009 version of the International Energy Conservation Code (IECC) is the most commonly adopted system in the U.S. and covers about 80 percent of the nation’s population. Modified continuously on three-year cycles, similar to the ANSI/ASHRAE/IES standard 90.1, the IECC is a relative newcomer. It is regarded as easier to apply, and interchangeable with 90.1 if a building team considers the more complex code appropriate. (Since IECC 2009, however, this option must be implemented across an entire building’s systems, not mixed system-by-system if lighting designers and mechanical engineers disagree.) Meres says that IECC 2009 was a major milestone in several regards: It was the first iteration to address residential lighting (requiring 50 percent of lamps in permanent fixtures to meet high-efficiency specifications) and it has been a strong driver of lighting upgrades in retrofits, assisted by American Recovery and Reinvestment Act funding for improvements to government buildings.

Because codes are implemented at the state level or, in home-rule states, at the local level, the legal conditions applicable to any new building can be complex. Municipalities are often allowed to develop their own code or to add specific requirements that are more stringent than the state’s adopted code. Heinmiller emphasizes the distinction between national standards (including voluntary programs like LEED and Energy Star) and local codes; knowing which code is in effect in a project’s jurisdiction is essential, he says. “A lot of times people hear, ‘Oh, 90.1-2010 came out, so that’s the new energy code.’ Well, it’s the new model, but it isn’t code until somebody adopts it.”

As updated in September on the U.S. Department of Energy (DOE) online map (, commercial construction codes in 34 states and territories use the 2007 version of 90.1 or IECC 2009, both of which were regarded as game-changers. A few states adhere to different-generation codes, older or newer. “Some states have no statewide energy code at all,” Heinmiller adds, “even though technically the federal law requires [them] to adopt an energy code of a certain stringency. There’s no enforcement mechanism for [the] DOE to make the states do that, so some states just don’t.” For commercial buildings, these states are Alaska, Arizona, Wyoming, South Dakota, Kansas, Missouri, and Maine, as well as the U.S. territory of American Samoa, with Mississippi added to the list for residential buildings. Jurisdictions that are without codes tend to be those where most of the construction is smaller single-family residential, or where little construction occurs.

California, where per capita energy use has remained flat for a decade, has long regarded prevailing nationwide norms as inadequate. The state has its own code, the influential Title 24, along with the nation’s highest-developed industry of energy modelers and other compliance professionals. Massachusetts offers an optional “stretch code,” which is a municipal overlay of higher efficiency standards (about 20 percent better than the IECC 2009) covering new residential buildings and many new commercial ones in about 185 of the commonwealth’s 300-odd towns and cities. Firms working in Massachusetts need to know whether a project is sited in a stretch-code town.

Replacing this patchwork with a uniform national code would simplify matters greatly, but Heinmiller regards this as a political impossibility, given the philosophical contrasts between environmentally progressive leadership in some areas and “don’t tread on me” attitudes toward regulation in others. “If you overlaid the red state/blue state map on top” of the DOE’s map of state code adoption, One Lux Studio’s Jack Bailey says, “there’s probably a pretty high correlation.”

This situation may change as new standards emerge, if some states leapfrog from older versions (or none) to newer ones. Where municipal codes are more advanced, state-level adoption of a new version would render them moot. This may happen to New York City’s code, Bailey says, after New York State updates its code at the end of this year (it is projected to adopt IECC 2012), unless the city upgrades its code again after the mayoral turnover.

The prescriptive nature of U.S. codes, Meres says, is both a strength and a limitation. In locations where most construction is residential or small-scale commercial and architects are often not even involved, “a general contractor can very easily read the code, understand the prescriptive provision, install what it tells you to install, and be in compliance,” Meres says. “There is an argument for the simplicity on the prescriptive path, but I think that simplicity can deter innovation”—though codes, too, sometimes restrict use of new technologies. Manufacturers may improve products’ performance for the sake of above-code options such as LEED, Energy Star, or the Home Energy Rating System (HERS), but those programs’ relatively small market share means that the mass market has little incentive to go beyond requirements. “On the residential side, I’ve heard that about 40 percent of new homes get a HERS rating,” Meres says; the proportion of commercial construction meeting LEED standards is lower.

The periodic IECC revisions, Meres adds, are “quite frankly a crapshoot,” since they attract immense lobbying by commercial interest groups, which “can tweak those numbers to what they think is right, whether they’ve done the analysis or not. … With the prescriptive requirement, they can predict what products they need to make and what they’re going to sell, based on the states that adopt it. When you have a building-level requirement that sets an EUI [energy use intensity] or some other energy target, they have no idea; they just need to make a good product, and hope that builders are going to buy it and architects are going to specify it.”

His European colleagues find the IECC system puzzling, and Meres describes it diplomatically as “uniquely American.”

European Codes: Performance-Based and Standardized, yet Flexible
In the European Union, which is a free-trade zone as much as it is a political entity, the regulatory approach leans more toward consistency, says Peter Raynham, senior lecturer at the Bartlett School of Graduate Studies, University College London. “National standards which don’t follow the European standards are regarded as non-tariff barriers to trade,” Raynham says, “so they start to get removed.” The European Commission’s 2010 Energy Performance of Buildings directive requires each member nation to have a national method for calculating a building’s energy performance, such as Part L of the Building Regulations for England and Wales and equivalents in other areas, and each nation has to upgrade this method every five years.

“The very lazy nations,” Raynham says, adopt the continent-wide calculation format of the European Committee for Standardization (or CEN, which is short for Comité Européen de Normalisation). Lighting is covered in CEN EN 12464-1. “What they do in the U.K. and a lot of other places,” he says, “is, you assess the energy that’s going to be used in your building, and then you rerun the calculation inside the calculation model, using a notional building,” which the real building must outperform.

The approach is more dirigiste, but commentators note that by focusing on building-level metrics and refraining from prescriptive norms on specific components, it also allows a designer flexibility in meeting the energy threshold. As long as a building’s overall EUI per unit area is within the limits for the building type, regulators are largely indifferent about how it gets there. Raynham does note that the U.K.’s energy-certificate system has “backstop values for each subsystem” and A-through-F letter grades for both subsystems and the building as a whole. A building with a need for high light levels can compensate by having a higher-performing building shell or HVAC system. “Overall, in the EU, energy efficiency is more culturally expected,” Meres says. “It’s very much dictated from the top down, and I think some of their lighting innovations have come about just because it’s more culturally accepted, and others because they’re not held strictly to a lumens-per-watt [standard] or lighting power density, like we are under the U.S. prescriptive codes.”

The Simplified Building Energy Model (SBEM), which is a software tool developed by the Building Research Establishment in the U.K., calculates CO2 emission equivalents for new buildings and it assists in compliance with Part L. Other nations are implementing their own version or equivalent. “If you get a bunch of building engineers together,” Raynham says, “the one thing they’re going to complain most about is SBEM and how it’s useless.” Nevertheless, software-based performance analysis is advancing on both sides of the Atlantic. Meres has heard from code officials in California and Florida that 90 to 95 percent of new buildings in those two states are being built according to a European-style performance path, in part because user-friendly performance software has become available.

Germany’s legal requirements for office workers’ access to daylight have had an influence extending beyond their legal reach, affecting the wider design realm. Building envelopes meeting these standards tend to have ample fenestration, limited depth, and very large floor-to-ceiling heights—typically 4 meters (13.1 feet), compared with the 2.7-meter (8.85-foot) norm in the U.K. and comparable heights in the U.S. “If you look at the London market for office space [and at] rental values, it’s only the office space that meets the German rules that attracts the premium rent,” Raynham says. “You can’t see a law firm wanting to let their senior lawyer be more than 15 meters from a window. So they’re not as daft as they say.” (Bailey says that different nations have approached daylight regulations as a matter of protecting workers’ rights, as in Germany and other continental nations, or of property owners’ rights, as in the U.K. or Japan.)

Raynham, appointed by the British Standards Institution, currently leads a CEN working group (composed of lighting designers, engineers, academics, public officials, industry representatives, and trade-association representatives, with active members from 13 nations, who are developing a European standard for daylight performance that will define good working conditions, including certain amounts of daylight, views, and freedom from glare. These regulations are being written to be informative rather than normative, he says, to avoid contradicting multiple national laws until an EU directive can cover the subject. Local architectural traditions in northern and southern Europe, he notes, have long accounted for different levels of daylight, “so you have to write the standard in a way that promotes the use of daylight everywhere, but allows for the fact [that] the south wants to exclude it more than the north. It’s a nightmare for standard makers, but we try to be fair, and so you can’t destroy vernacular architectural styles with a standard like that.”

Another performance-oriented German innovation, the Passivhaus system, is attracting attention in both European and American markets, though it serves a niche market and is probably too rigorous for general use. Its lighting component emphasizes daylighting through building orientation and appropriate fenestration. Raynham notes that the impressive energy savings of Passivhaus can involve tradeoffs that lower overall sustainability. “It makes you do some strange things to buildings to make it work, and they’re not always that carbon-efficient”: e.g., specifying electric cooking rather than gas, so that air-exchange rates are lower. That’s “fair enough,” Raynham says, “but [as for] the carbon footprint of the electric cooking: Because the carbon’s outside the building, it doesn’t count.” As in so many aspects of environmental performance, there is no free lunch.

Yesterday’s Options, Tomorrow’s Mandates
Codes and the LEED system (or their equivalents, such as the U.K.’s BREEAM or the United Arab Emirates’ Estidama) are converging, particularly in lighting. Still, the U.S. Green Building Council is a private organization, and its point system does not have the force of law. With the 2013 version of the ANSI/ASHRAE/IES standard 90.1 nearing completion and IECC 2015 on the horizon (the final action hearings take place in Atlantic City, N.J., this October), Bailey says that LEED-point options five or six years ago may attain mandatory status in next-generation codes. Lighting power densities dropped significantly in the 2007 version of 90.1 and in the 2009 version of IECC but have not undergone such sharp reductions since, except for particular spaces such as lobbies. Instead, requirements for controls are accelerating. Within five years, Bailey predicts, codes will require daylight-responsive controls or occupancy sensors in most spaces. IECC 2015, he adds, should also benefit from unprecedented involvement by IALD members.

Adopted at statewide levels by five states as of July (Florida, Maryland, North Carolina, Oregon, and Rhode Island) and various municipalities, the IgCC may represent the future of codes, codifying principles that were previously voluntary. Unfortunately, Bailey points out that its implementation has lagged because of timing: It was published during the global economic slump, when little was being built, permit fees were scarce, and enforcement departments were on tight budgets. It was “exactly the wrong time to be coming out with a green code,” he says, “because people weren’t forward-looking.” He says the IgCC’s requirements, which he helped develop, are the first step toward mandated daylighting of major building-use groups (businesses, schools, factories, retail, and others) in any U.S.-based code. “Worker productivity, enhanced learning, absenteeism—all those issues are possibly less important than the biological impacts of light, which is something that we know a little bit about, but which is still not really informing design practice at all.” The IgCC also explicitly addresses a major limitation of LEED to date: the cost barriers to certification for smaller buildings.

The question of whether codes drive new technology or vice versa leads to chicken-or-egg speculation. For Heinmiller, codes have generally lagged behind technology. As an example, he points out that in the tungsten-lamp era, about 20 years ago, allowable lighting power densities were higher than they needed to be since more-efficient fluorescents were being released. Densities dropped with the 2004 iteration of 90.1, and they are likely to drop again in the next generation of both U.S. code systems as the transition to LEDs accelerates. The 2013 version of 90.1 reflects deliberations that began in 2011, Heinmiller says, when LED products had not gained significantly in efficiency; the reduction in lighting power densities may look alarming at first, but the LEDs that are likely to be in wide use in a few years will make them achievable.

Technological change and code revision “very much go hand in hand,” Raynham says. “The cynic would say that the technological change drives the law, because the people who have the technology also have the budget to go political lobbying.” In Europe, he observes, politicians “back away from it and push it out to the standards makers, [who] by and large are the experts” and are more insulated from commercial pressures.

He sees the integration of daylighting and electric lighting as a critical area for the new codes, raising certain challenging scenarios. “Technically, [when] lighting controls go into an installation, they’ve got to last 25 years. The problem is that, generally, you reconfigure your building every five years. The controls company that made it [the controls] goes broke in seven to 10 years, and that [means] the technology becomes unsupportable in that short period. So there are real nightmares in facilities management, and that’s probably an issue that needs to be dealt with. I think you have the same problems in the U.S. I just don’t think you’re quite as far down that particular path yet.”

The Achilles’ heel for any code system is enforcement. “The numbers on compliance rates will go all across the board,” says Meres, who describes his work with the Global Buildings Performance Network as “getting building departments to recognize that energy-code compliance is an issue and giving them the tools to do so.” Compliance with 90 of 100 specific requirements implies nothing about a building’s performance, because the noncompliant 10 percent may account for disproportionate effects. Across the U.S., he says, the best general compliance rates are found in the Pacific Northwest.

Colleagues in Paris have also told him that “they actually think compliance is a huge problem in Europe, but they’re not sure how to tackle it yet.” Post-occupancy evaluation and public disclosure of results, he says, are powerful tools, citing several salutary examples: EU-wide labeling requirements (despite varying implementation by member states); Washington, D.C.’s local requirement that Energy Star Target Finder scores be submitted with permit applications; and New York City’s requirement that private buildings disclose their energy consumption. As the green-building sector matures, increasing public attention to metrics and accountability creates a demand for clear, substantive information about what it means for a building’s components to be up to code.