A DALI Checklist: Things to Keep in Mind

January 5, 2011 / no comments

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DALI is one of the latest buzz words in the lighting industry. Widely used in Europe, DALI is still in its infancy in the U.S., even though it was first introduced in the late ’90s. DALI stands for “digital addressable lighting interface”, a control protocol based on digital commands that are sent between ballasts and the control system. DALI has many benefits which make it a very attractive system for commercial lighting applications, however, there are a number of things to keep in mind when designing a DALI system.

How does DALI work? DALI is a standard digital communication protocol which allows DALI-compliant devices, regardless of manufacturer, to talk to one another. These devices include controllers, ballasts, switches and sensors. Since DALI is an open protocol rather than a proprietary system, there are a number of ballast manufacturers and control companies that offer DALI products.

A DALI system can include up to 64 individual DALI devices on a single loop, with each device having its own address. DALI ballasts can be individually configured, and that custom configuration resides in the electronics within the ballast itself. DALI ballasts are able to set light levels, fade time and fade rate, and individual address. These ballasts are able to be configured as part of multiple lighting scenes which can be selected by wallbox control devices or a central control system.

DALI ballasts feature two-way communication, which means that they receive digital signals from the control system telling them how to operate, while also allowing the ballast to provide feedback through the network, for instance, indicating if the ballast is on or off, how much energy it is using, and whether the lamp and ballast are functioning.

DALI systems have many attributes which make them worthy of consideration for commercial applications:

  • With DALI, wiring is easier than in a traditional system and there is less of it. The electricians don’t have to care about how they circuit the fixtures. They just run power to fixtures the easiest way they can until they load up a circuit. Fixtures are controlled solely through the digital control wire, which can also be run arbitrarily to each device.
  • The ballasts are individually addressable, allowing for control zones to be configured in the field – rather than on paper, prior to construction. Because control zones are not hard-wired, they can be easily reconfigured based on real usage. Programming zones and scenes is done through software, regardless of how the fixtures are circuited.
  • DALI ballasts can be tied into Building Management Systems, which can monitor energy usage and identify lamp failures, making DALI an ideal system for clients interested in sustainability.
  • DALI ballasts can dim to 1% for linear lamps and 3% for compact fluorescent lamps – this is of particular interest when considering daylight dimming along perimeter zones.

While there are quite a few positive features to a DALI system, there are a number of things to keep in mind when designing such a system:

  • At the moment, there are a limited number of ballast types available. While the choices are vast in Europe, as of this writing, U.S. manufacturers only offer DALI ballasts for four-foot linear fluorescent lamps (T8, T5, and T5H0), two-foot T5 lamps, 18/26/32-watt quad- and triple-tube compact fluorescent lamps, and 40-watt biax lamps. There are no manufacturers in the U.S. currently offering a three-foot linear fluorescent DALI ballast. This proves problematic if designing continuous coves or slots, which can require three-foot units to make up a continuous lighted run.
  • Something else to consider is the inability to locate a DALI-compliant ballast remotely. Lighting fixtures are becoming smaller and smaller due to the demands of both designers and architects, and in some cases the ballasts just don’t fit inside the fixture housings. For a DALI system, designers can select only fixtures with integral ballasts, because as of this writing, DALI ballasts cannot be located outside the fixture.
  • Another factor is that many people are hesitant about implementing a DALI system because they just don’t know enough about how it works. There is the notion that a DALI system will cost more than a traditional system, however, one must consider the lower cost of installation and simplified wiring configurations.

While DALI might not be right for every application, and it does indeed have some drawbacks, the time might be right for more DALI installations in the U.S., and perhaps the U.S. ballast manufacturers will soon start developing and offering more options for DALI ballast/lamp combinations – especially when it comes to three-foot lamps!

Photo Credit: © Carlene Geraci/Lam Partners

The Color of Light

November 15, 2010 / no comments

Despite some of their current shortcomings, we are all enamored with the hope and promise of LEDs. When we begin a design session with a client these days, it’s a matter of minutes until someone asks “can we use LEDs for that?!” We respond with the usual overview that there are some very good LED products on the market now, but there are also a lot of poorly-made products, snake-oil sales claims, and companies without a proven track record. In essence, “proceed with caution” is our approach.

One of the things that has bothered me most about LED fixtures is their visual color temperature. The products that I have seen and tested give off a light that is too cool for my preference. But, the world is changing and perhaps my perspective is starting to change a bit too. The following is A Tale of Two Task Lights: a Recently Acquired Fixture and the Lessons Learned.


Good tales often begin with a historic perspective, and so shall this one. Throughout the ages, people have associated low-level lighting with the warmth of firelight or of a candle. I confess that I love the warmer color temperature of a halogen task light. My desk lamps and even the under-cabinet lighting in my kitchen have always been halogen.

The indirect fluorescent lighting that I also have in the kitchen provides a very energy-efficient and comfortable ambient light level in the evenings, but the color does not deliver the same warm glow as the halogen. When the under-cabinet halogen lights are dimmed, they get even warmer and more ‘buttery’. I have yet to achieve that same warm, low light level with LED, compact fluorescent, or linear fluorescent products.

From among the outpouring of new LED products, I purchased my first LED task light this year. I did this to begin to wean myself off of my halogen diet, or at least to try in good faith to live with this new technology. Perhaps it also relates to the overall picture of striving to live healthier and in a more sustainable way. I suppose a parallel could be made with eating healthier – using less butter and more olive oil, for example. Yes, I started to compost as well.


I put my 50-watt, 2850K halogen task light into storage, and began to use my sleek new 9-watt LED desk fixture. The color temperature is specified at 3000K. For the first month or two I had a knee-jerk negative reaction whenever I turned it on. Too cool – as in temperature, not hip factor. I missed that warm buttery glow. However, over the course of a few months, I am beginning to grow accustomed to its cooler cast. The fixture has excellent glare control and the output is comfortable. If the fixture produced glare, or was either too dim or too bright, those factors would have certainly biased me against the LED task light. But I couldn’t find fault with it in those areas.

It has been about six months and I am now acclimated to the light quality of my new task light. I enjoy using it and the color temperature has sort of grown on me. Does making healthy choices involve accommodation and adjusting our standards, or is it the retooling our thinking and attitudes, which open us up to new options?


I believe that, as LEDs become more widespread in offices and homes, retail, street lighting, parking garages, etc. in the next few years, their shortcomings – particularly in the area of color temperature and glare control – will cause a backlash among users. The marvels and mysteries of LEDs as the great hope for our future will be tarnished by products that don’t live up to their promises and our expectations. While I do believe that the industry will have to deal with these shortcomings, what I have learned is that people are surprisingly adaptable to new technologies.

The visual issues that manufacturer’s have been dealing with – glare, multiple shadowing, effective dimming, cooler color temperature, and that strong desire for warmer color temperatures when dimmed – will get worked out over time as we grow accustomed to a new light.

Photo Credits: Schani (1), Lam Partners (2, 3)

By the Time You Read This, Your Compact Fluorescent Lamps Will Have Come up to Full Brightness

October 26, 2010 / no comments


Ever walk into a room, turn on the lights, and think, “This is really not as bright as I would like it to be,” then walk out and come back later to find the lighting is actually just fine? The reason for this lag in full brightness is the same whether for a commercial office project lighted with compact fluorescent (CFL) downlights, or at home where screw-in base retrofit CFL lamps have been used in formerly incandescent table lamps and pendants. That reason – amalgam technology.

I know you’re thinking that this is just not going to be something you need to know – unless you are trapped at a really boring party – but as fluorescent lamps become de rigueur in replacing inefficient incandescent lamps, it really is good to know a little bit about their inner workings.

All fluorescent lamps, whether linear tube or compact fluorescent lamps, contain MERCURY. The mercury, when heated by the incoming electrical current, is vaporized and converts electrical energy into ultraviolet radiation. The phosphor coating on the inside of the glass tube absorbs the ultraviolet radiation, and converts it into visible light.

In linear fluorescents, mercury is provided in a liquid or pellet form. But all of the twists and bends in a CFL cause liquid mercury to pool when the lamp is installed in different orientations. As a result, the mercury does not vaporize or distribute effectively. To resolve these issues, amalgam technology, in which mercury is imbedded in a metal alloy, was created to allow more stable light output, independent of burning position. Since the mercury is contained within the amalgam, the lag time to heat the amalgam and release mercury vapor creates the lag in light output; CFL lamps will take as long as 110 seconds to produce 80% of their total lumen output.


Mercury is the dark side to the green story of fluorescent lighting; it’s essential, and it’s a poison. During the lifetime of a lamp, the mercury that is available to be energized is used up – bonded to the glass and phosphors. This reduced level of mercury will, for a time, allow the lamp to create light, but not enough to overcome the presence of the argon gas within the tube, resulting in a fatal, eerie bright pink glow.

The glass tube of the fluorescent lamp does create a sealed environment, so although the lamp no longer produces useful light, mercury is still present. Should a lamp break, whether linear or CFL, extreme care should be taken in disposing of not only the shards of broken glass, but also the powdery phosphors, which have now bonded with vaporized mercury.

Even though some lower-mercury lamps labeled as TCLP compliant are touted as having mercury levels lower than those regulated as hazardous waste, and could avoid additional disposal costs, recycling is still the best way to allow mercury to be reclaimed and stay out of the landfill environment. Recycling of screw-in base compact fluorescent lamps also allows the ballast components in the base of the lamp to be recycled.

And while amalgam technology allows for better recycling of mercury, it does mean that slightly more mercury is going into the lamp system. The LEED program is now allowing Innovation in Design credits to be awarded for the use of low-mercury lighting. This recognizes that while mercury is a fact of life in energy-efficient lighting, there are ways to minimize the total amount of mercury on a project (this includes high-intensity discharge lamps as well). Satisfying this credit entails meeting the target maximum for mercury content, and ensuring that 90% of the lamps purchased for a project comply with this target level – this puts amalgam technology CFLs at a disadvantage compared to linear fluorescents.

So, think incandescent lamps are a way to avoid this messy bit of mercury business? While incandescent lamps do not require mercury to operate, fluorescent lamp and sustainability advocates have computed the theoretical environmental mercury exposure created by the use of incandescent lamps powered by electricity from coal-burning power plants. This number is over three times the amount from compact fluorescent lamps.


Photo Credits: Horia Varlin (1), Michael Hicks (2), Wikipemedia Commons image (3)


Works Cited:

“Amalgam for Use in Fluorescent Lamps Comprising Lead, Tin, Mercury Together with Another of the Group Silver, Magnesium, Copper, Nickel, Gold and Platinum. – US Patent 5952780 Description.” PatentStorm: U.S. Patents. 14 Sept. 1999. Web. 15 Oct. 2010.

“Amalgam Technology.” Megaman Global: Green Room. Web. 15 Oct. 2010.

“Compact Fluorescent Lamp.” Wikipedia, the Free Encyclopedia. Web. 15 Oct. 2010.

“Fluorescent Lamp Containing a Mercury Zinc Amalgam and a Method of Manufacture – US Patent 5882237 Description.” PatentStorm: U.S. Patents. 16 Mar. 1999. Web. 15 Oct. 2010.

“Fluorescent Lamp.” Wikipedia, the Free Encyclopedia. Web. 15 Oct. 2010.

Harris, Tom. “HowStuffWorks “How Fluorescent Lamps Work””. Howstuffworks “Home and Garden” Web. 15 Oct. 2010.

A Daylighting Pattern Language: Deep Apertures

September 27, 2010 / no comments

Le Thoronet is one of three wonderful Cistercian abbeys in Provence, built around 1170. In the mid-twelfth century this part of southern France was not a major tourist destination. The monks who built Le Thoronet were avoiding the political intrigues and feudal power struggles of the cities by locating in a remote area, and they weren’t necessarily welcoming company. And they were building for eternity, too, so the walls are thick, sometimes over three feet thick. As with a lot of ancient masonry construction, this has a salutary effect on the way daylight works in the interior. Why?

In contrast to today’s vogue for all-glass buildings, how is it that massive masonry construction can result in wonderful daylighting? This has a lot to do with contrast control, which is related to the deep apertures created through the thick walls.

Because sunlight is such a powerful light source, a major challenge with daylighting is to moderate the contrast between very bright exterior views and the relatively much darker interior surfaces. In particular, the interior face of the wall containing the window often tends to be the darkest surface in the entire space, since it may receive no direct daylight at all. This can result in very harsh contrast at the apertures. But, when the aperture has depth, the sides of the opening provide extensive surfaces with a brightness that is intermediate between exterior and interior, graduating the contrast.

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Without this kind of buffer, the contrast is often more than the eye can comfortably accommodate. If splay or architectural ornamentation is present in that zone, the contrast gradient is even more improved; the ornamentation itself is beautifully rendered by the raking light and brightness gradient from exterior to interior.

In addition, those surfaces, especially the sill, diffusely reflect daylight into the interior – for example, illuminating the ceiling even though most of the original daylight source is heading for the floor.

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These are daylighting principles we would do well to emulate in our designs today. We’re rarely going to have walls three feet thick to work with, but we can accomplish similar effects by, for example, positioning our apertures against flanking walls or piers. In this house by Tadao Ando, the room surfaces perpendicular to the apertures have a brightness intermediate between the view outside and the darker interior surfaces. In addition, they diffuse daylight back onto the inside surface containing the aperture, which further softens contrasts.

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The deep aperture approach lies in stark contrast to just treating daylight apertures like simple holes in the wall. Besides improving contrasts, the deep aperture uses daylight as a powerful expression of the extension of space.

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Photo Credits: Betina (1), Nicola Comodo (2), Glen Craney (3), Lam Partners (4-5)

Specification Grade Sustainability

September 13, 2010 / no comments


Recently a lighting company came into our office to show us their new LED fixture. I prepared myself for the usual spiel: tight quality binning, a high-performance heat sink, ELV dimming option. However, this particular fixture had been designed in a way that we haven’t seen from many other companies: the entire fixture, an LED cove/grazer product, was actually designed along sustainable manufacturing principles. Its connected load is more energy-efficient than that of its fluorescent counterparts (finally), but more impressively, the materials used to construct it had been thought through in a way few other products seem to manage.

The housing was not anodized aluminum, the standard seen in LED fixtures required for heat dissipation, but a zinc-based alloy that is less energy-intensive to make, and requires none of the toxic anodizing processes. The fixture is highly segmented for adaptability, and all components may easily be removed if failure occurs, allowing for easy replacement of parts. I was shocked.

Two years ago, before I left Lam Partners to pursue a Masters of Architecture at the University of Michigan Taubman College of Architecture, white LEDs were standard in steplights and other specialty fixtures, but only just catching on in mainstream lighting design, with a few linear fixtures, floods and downlights. Those fixtures were not terribly competitive at the time.

Since returning to the firm for the summer, at least once a week a manufacturer has come to promote their new LED products. As one lighting manufacturer’s representative correctly noted, I’ve stepped into the future. The once over-priced and under-performing LEDs now stand beside traditional sources, and in many cases outperform them; costs are dropping while efficiencies continue to rise.

The LED revolution is obviously the greatest thing since sliced bread, the introduction of fluorescence, or of incandescence before that. But just as growing pains occurred at those phase-changes, this revolution too has seen a dark side. In this new world, the slightly ignorant marketer walks into our conference room spouting how their fixture is ‘sustainable’ simply because it uses LEDs, or maybe includes some recycled decorative glass. It seems fair to say that many manufacturers misuse the term ‘sustainable’ as a marketing ploy, with mixed knowledge of what is needed to create truly sustainable products.

I was therefore pleasantly surprised when this particular company actually walked the walk. They’ve produced a product that begins to address some unspoken facts of the lighting industry: lighting fixtures require vast quantities of energy to produce, ship, and install, and poorly designed fixtures equal waste.


The discourse on life-cycle costing was made popular by William McDonough and Michael Braungart in their book “Cradle to Cradle,” and for some manufacturers of architectural materials, it transformed the way in which their product is conceived, produced, bought, and utilized. Moreover, the general adoption of LEED standards has greatly influenced the purchasing power of clients, who, through their architects, now regularly seek architectural products that account for embodied energy in some way, such as sustainably harvested wood or recycled or re-purposed metals.

However, LEED does not currently allow MEP equipment to count toward credits for material usage, with the understanding that the material quantities are considered negligible, they are not permanent to the architecture, and ultimately their ability to efficiently use energy trumps any material concerns. This seems like a missed opportunity, as the material in MEP equipment is hardly insignificant, and in many cases could comprise recycled or re-purposed materials.

While operational energy accounts for the amount of energy consumed (power x time) by the product during use, embodied energy represents energy required to produce and transport the fixture, and how that energy becomes ‘trapped’ when the product enters the waste stream. A brick, for instance, has a relatively low embodied energy, requiring only the energy to collect the clay, fire it, and transport it, and then may be used multiple times before it crumbles and must be reformed (of course never once requiring connected load). The light fixture by comparison must be fabricated from an array of energy-intensive materials, like aluminum, steel, glass, plastics, and mined phosphorous (reserves of which, according to Wikipedia, we’re on track to deplete sometime in the next 100 to 300 years). These materials must then be assembled, requiring additional energy-consuming processes.


The current debate over LED lamps and fixtures exemplifies the necessity to think more constructively about lamp/fixture embodied energies and life-cycle costs. This is a two-part issue. First, LEDs are finding homes as retrofits: replacement lamps for old fixtures, and complete fixture replacements (as have also been seen with compact fluorescent or metal halide retrofits). If the fixture must be completely removed, the old product is often sent to the landfill, and in large-scale retrofits, this may be quite a sizable quantity of wasted metals.

Secondly, in the rush to get products out to market (for both retrofit and new construction), many manufacturers have created LED products with no option to replace failed components in the field, notably LED boards and drivers. Manufacturers tend to argue that, in order to achieve the desired output and long life, LED boards must be permanently attached to their heat-sinks, usually with some sort of thermal glue. This then gets extended to additional aspects of the fixture, including housings or reflectors. Apparently, to most manufacturers, in some glorious undetermined future utopia we won’t even have to worry about waste disposal… LEDs will last until our civilizations have long since perished, so it’s not even worth bothering with end-of-life issues. Unfortunately this leaves the end user with only one option when the fixture does, some time in the next 20 years (a brief blip in the realistic lifespan of a building), fail: completely remove the dead fixture and replace it with a new one. No governing body exists that demands that old MEP or lighting equipment be recycled or re-used in any way, so the manufacturer is off the hook.

One manufacturer suggested, as an option until they “figure out their policy on refurbishing dead fixtures”, that the specifier add the phone number of an ‘approved’ recycler into the notes column of the fixture specification, for the end user to contact at failure. This option certainly plays into the notion of American capitalism, but it is ultimately laziness on the part of the manufacturer. I would much rather put a note into the fixture schedule recommending that the end user contact the manufacturer or local representative to buy a replacement, at a discount in return for the dead fixture (assuming the fixture dies after the warranty period).


The manufacturer should be thrilled at this concept. They potentially regain a host of usable parts, which should be refurbishable, and moreover, they retain the business of the customer. This is already happening in the computer industry, as an alternative to shipping dead electronics to third-world countries where workers strip equipment under highly hazardous conditions.

For example, I currently have a three-year-old Macbook Pro. Still works, but running slow, and I’ll need to upgrade soon for school. Recently I went onto Apple’s website, and found that I could get a quote for my old laptop based on the model and working quality of specific parts (even if it was dead for some reason, I’d still get money back). By offering a trade-in for my old laptop that can be put toward the purchase of a new computer, Apple is not only able to recapture the energy they spent creating the old one (which can be refurbished and resold, or stripped for individual components), but they also retain my business for the new product.

Granted, Apple’s ubiquitous presence in local retail far exceeds that of any fixture manufacturer, so an alternative might involve local lighting representatives to build up quantities before shipping, which suggests that buying local MEP equipment also matters. Regardless, few if any lighting manufacturers have thus far marketed their products in this way.

The push to create highly energy-efficient, long-lasting LED replacements for inefficient technologies does allow for minimization of waste. But countless inefficient light fixtures are currently being pulled from ceilings in an effort to reduce energy consumption, arriving either in landfills (to be mined by future generations) or at recycling plants that must perform energy-intensive procedures to recapture materials. I would like to see future companies retrofitting old light fixtures with new light source technologies in the factory setting, and selling them alongside ‘new’ products. I look forward to the day when a high-visibility architectural project has only refurbished light fixtures installed. It may be my project.



As I implore manufacturers and lighting designers to consider life cycle as well as aesthetics and connected-load performance, the following are recommendations I would like to see incorporated into the ethos of the lighting industry:

To the Manufacturers:

In order to meet current LEED criteria pertaining to lighting, lighting must be incorporated into a design by an experienced design professional who is able to balance connected load energy usage and reduce light pollution across a complete layout of fixtures. In no way can an individual fixture really “help meet LEED” on its own terms. Blanket statements like these reveal the manufacturer as using jargon and marketing instead of truly attempting to make sustainable products.

Regardless of current LEED criteria, every material choice within a lighting product requires energy for production and disposal, beyond just connected load. These choices will begin to matter more to consumers in coming years. Prove that your fixtures were created sustainably, shipped sustainably, and can easily adapt to changes in technology or component failure for the lifetime of the architecture.

Components that may fail must be replaceable without requiring costly and wasteful entire fixture assemblies. When a fixture truly reaches the end of its useful life, provide robust programs that allow end users to return fixtures beyond warranty periods for rebates on replacements. Refurbishing the components of dead fixtures equal potential savings by keeping highly usable materials out of the landfill.

If in fact your products do go the distance, market these specifications! Is the fixture made of 100% recycled aluminum? Put that on the spec sheet! Can the plastics be disassembled and recycled? Clearly stamp those materials with the well-known ‘recyclable’ symbol with material type (in a location that will not affect light performance).

And finally, or course all manufacturers should commit to ‘greening’ operations and products – but do not roll out one product as your ‘sustainable fixture’ without also providing a plan to overhaul the rest of your product line and manufacturing operations. It’s hypocritical.

To the Designers:

Why not specify refurbished lighting products? Must the back-of-house troffers be made of pristine aluminum? Actively look for ways to minimize not only watts, but material-heavy fixtures, with preference given to the lighter, refurbished, or recycled products. Minimize the use of fixtures made from materials with energy-intensive or toxic manufacturing processes.

How can the architecture itself serve as a lighting system? Thoughful design can allow for replacement of the minimum quantity of material when technology changes, and allows renewable materials to do some of the lighting work, such as in valances or coves.

Finally, demand more from your product manufacturers. Lighting may be a relatively small piece of the puzzle, but it’s the piece over which you have control. Make the most of it. Specify high-performance sustainability.

Photo Credits: Dan Weissman / Lam Partners Inc


New Energy Codes, New Challenges

May 10, 2010 / no comments


Readers of this blog have already heard about the new Green Building codes, but there are new versions in the works, both of the energy code standard ASHRAE/IES 90.1, and of the International Conservation Code (IECC). What will these codes look like, and how will they affect the work of architectural lighting designers?

The 2010 version of ASHRAE/IES 90.1 will be published this fall. Standard 90.1 is the benchmark model energy code. Although rarely adopted directly as code, it is an alternative path for IECC compliance; it’s also the energy performance reference for both the US Department of Energy and the LEED rating systems, and is highly influential, like California’s Title 24, as a trendsetter.

ASHRAE’s goal for the 2010 version of 90.1 is to be 30% more stringent than the 2004 version. Standard 90.1-2010 will have lighting power allowances that are significantly lower than the 2004 and 2007 versions. Additionally, there will be many new controls requirements such as mandatory use of occupancy sensors in some spaces, incentives for daylight responsive controls, exterior lighting after-hours shut-off, and controls commissioning requirements, among other things.

The IECC is currently in the middle of its three-year development cycle. IECC-2012 will be published in April 2011. The goal of the Department of Energy and other stakeholders in IECC development is for IECC-2012 to be 30% more stringent than the 2006 version. It’s a little early to know for sure what will be in the next version, but expect reduced power allowances, and the addition of a space-by-space method for determining lighting power densities. Another concept that’s been proposed is the “Additional Efficiency Package Options”. To comply, the project will have to pick one option from a menu of energy-efficiency provisions like more efficient mechanical equipment, onsite renewable energy, or reduced lighting power allowances.

But here’s the thing to keep in mind: even though these new standards will be published soon, they don’t become code until they are adopted by individual states. By federal law, the DOE must evaluate each new version of 90.1 to determine if it is more efficient than the previous version (and because IECC offers 90.1 as an alternative compliance path, it piggybacks on the DOE determination). If the standard is found to be more efficient (and it will be), states are required to adopt an equally stringent code within two years.

But, enforcing this provision and getting the states to adopt the latest code is easier said than done. Currently, only ten states have adopted the most recent standard, IECC-2009/90.1-2007. At the other end, eleven 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. This lag is typical, but I expect it will decrease, given the global push to reduce energy consumption and greenhouse gas emissions. If states follow the example of my home state of Massachusetts, then code lag 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.

One school of thought says that these new standards will be overly stringent and will make it impossible for designers to produce quality results. I don’t agree with this opinion. Through my work as Chairman of the IALD Energy and Sustainability Committee, I’m pretty familiar with what is likely to be in these standards. We’ve been working hard to make sure that the codes are as aggressive as possible, but without prohibiting quality design. I believe that the new standards will only codify what any responsible designer should already be doing to reduce the negative environmental impact of their design. And, I do not think that they will prevent us from producing effective, comfortable, and beautiful spaces.

Yes, it will be harder. The “cushion” will be gone; we will have to be very careful with our use of energy in order to meet code. Competency in lighting design will require deep knowledge of code requirements, the skill to get the most out of limited power budgets, and expertise in lighting controls technology and system design.

Image Credit: D-32

Will Green Building Codes Leave You Seeing Red?

February 24, 2010 / no comments


Now that ASHRAE/USGBC/IES Standard 189.1 has been published, it’s time for the building design and construction communities to consider the implications of the new green building codes coming out.

What is a green building code, and why do we need one? Imagine LEED written in code language – site sustainability, water use, energy, indoor environmental quality, materials and resources. We need green building codes because LEED is not a code; it is a voluntary rating system, not a mandatory code.

Many cities and states desire a green building standard that they can apply as code or ordinance, or through “green” legislation. To meet this need, some cities have adopted LEED as a requirement. For example, Boston requires that projects over 50,000 square feet be “LEED certifiable”. The City can’t require you to be officially LEED certified, and because LEED is a points-based rating system, there are many ways to achieve “certifiabilty”. Messy, hard to enforce – LEED is not a legal code and the USGBC does not want it used as a code.

Thus, the motivation for ASHRAE, the USGBC, and the IES to team up and create a green building standard, written in code language and ready to be adopted by any municipal or state government. It has taken several years and four public review drafts to finally get Standard 189.1 on the street. And it is still a work in progress; proposals are already being accepted by ASHRAE for changes to the standard.


Fine, you say? Sounds like a good idea, let’s see what happens? Sorry, it’s not going to be so easy – there is another green building code in the works! Have you heard of the IGCC, the International Green Construction Code? Same idea, but this time from the ICC and the AIA! (The ICC is the International Code Council who brings you the IBC and the IECC) This code has been in the works since last summer and the first draft for public review is expected March 15th. The code will be finalized at the end of next year and published in March 2012.


So what will happen? Which code will be adopted? Will they be adopted at all?

Standard 189.1 has the advantage in that it is already available, a full two years before IGCC will be ready. But the IGCC will be from the “code guys” who provide all the building codes typically being adopted in the US, so perhaps it is a more likely candidate. Worst-case scenario: in three years we have two green building codes being adopted by towns and states scattered across the country. Building design and construction professionals will have to be conversant in two different green building codes – in addition to LEED! And for each city and state we will have to keep track of which code applies, and how it is used. Perhaps one city decides that they will only apply the green code to city-funded projects, or to projects larger than 25,000 square feet, or…?

The other thing to think about is the relationship of green building codes to energy codes. The assumption is that the energy provisions in a green building code are more stringent than the applicable energy code, which would be superseded. But what if a state or locality adopts an energy code that is more stringent than the green building code they have previously adopted? Someone will have to sort this out.

And if your head isn’t already hurting, try this: you are designing a LEED project in a town that has adopted a green building code. So, now you have to design to two different green standards -every design option would have to be tested twice. And you’d have to do the calculations and documentation twice to prove compliance with each provision.

I hope someone at the USGBC is thinking about this. I know that those of us on the IALD’s Energy and Sustainability Committee have been thinking about it. Through our work on standards drafting committees, and through public review commenting, we are striving for consistency between all electric lighting and daylighting related provisions in 189.1, IGCC, and LEED.

But have you heard about CALGREEN, California’s new mandatory Green Building code? Oh, my.


Image Credits: ASHRAE (1), ICC (2), Lam Partners (3)

Dawn of the Daylighting Codes

December 21, 2009 / no comments

It’s pretty safe to say that people like daylight and sunlight. Daylight is good for people, since it sets our biological rhythms, gives us a connection to the weather and time, keeps us physically and mentally healthy, and obviously allows us to perform visual tasks. It’s no wonder then, that architects through the ages have designed architecture to effectively introduce sunshine and daylight into building interiors – not only to sustain human life, but to allow it to flourish.

Daylighting has been an integral part of the built environment throughout architectural history, and structures that are thousands of years old are still revered for their daylighting qualities. “The history of Architecture is the history of man’s struggle for light – the history of the window,” wrote Mies van der Rohe.

It’s only within the last 75 years or so that daylighting has been supplanted by electric lighting as the primary source of interior daytime illumination. Ever since the introduction of air-conditioning, and especially of modular gas-discharge lighting (i.e. modern fluorescent lamps), windows and skylights have been getting smaller and floor plates have been getting larger. Our luminous environments have been deemed adequate and appropriate based on a simple numerical criterion, horizontal footcandles. However, in recent years, especially with the ‘green’ movement, there has been much more pressure to re-introduce daylight back into our interiors and create daylit architecture once again.


But what exactly is ‘Daylit Architecture’? It’s difficult to define. For architects it may be about beauty and ergonomics; for engineers it tends to be focused on energy and economics. Fortunately, with recent studies, we finally have hard evidence showing that daylight in schools improves test scores, and daylight in the workplace improves productivity. In retail, it boosts sales; in hospitals, it reduces recovery time. These studies embolden the stance of the ‘quality’ seekers.

But, on the other side are the energy tyrants. They want to see fewer windows in architecture since windows are terrible insulators. The criticism is real. News stories are unfolding about LEED buildings and how they are not living up to their touted energy claims. But the LEED points for daylighting and views have nothing to do with saving energy. It’s all about interior environmental quality.

So now, there is a bigger push to improve energy usage and enforce ‘green’ building codes. LEED, CHPS, and other programs give you the option of getting daylighting points. A ‘green’ code will require it. There has been overwhelming support for some type of daylighting requirement or code, but the problem seems to be in writing one. Most would agree that, if introduced properly, daylighting can save energy associated with interior illumination. The more difficult aspect is quantifying quality. How do you require architecture to beautifully introduce daylight and sunlight into itself?

Codes requiring access to daylighting are relatively new to the United States. Title 24 in California already requires daylighting in certain buildings. There’s a rich history of codes requiring access to daylight. An English law dating back to 1663, Ancient Lights, is a form of easement that gives owners of a building with windows a right to maintain access to daylight. Justinian Code in the sixth century AD included sun rights, laws to ensure that every homeowner had reasonable access to the sun. And, many modern European codes require daylight and views for workspaces and classrooms.

Get ready for daylighting codes across the United States. Come late spring 2010, ASHRAE will have introduced its new Standard 189.1, which is basically a ‘green’ standard that goes beyond the energy-saving measures published in ASHRAE Standard 90.1. It also contains a lot of language about minimum amounts of windows and required illuminance from daylight. The other big player is the International Code Council, with their new proclamation, the IgCC, or ‘International Green Construction Code’. In that particular code, the daylighting portion will most likely be broken into two sections: energy and indoor environmental quality. This approach makes the most sense for both camps. We want enough daylight and views to elevate the human spirit, but not so much as to cause glare or unnecessary energy usage associated with excessive cooling loads.

It won’t just be footcandles and daylight factors anymore. Relatively new metrics such as Daylight Autonomy, Daylight Saturation Percentage, Useful Daylight Illuminance, and Daylight Glare Probability may become common language within these new daylighting codes.


It’s probably time that we have some sort of code that protects and even encourages our access to our greatest energy source, the sun. How it is written makes all the difference. It cannot reward poor design, or suffocate good design.

Great daylit architecture comes from the brilliant architects and designers who create it, not from a formula or code. But gone are the days of overly-glazed façades used in the name of ‘daylight’. Responsible practice must produce sustainable architecture, even if it has to be mandated.

Photo Credits: Elinnea (1), Roryrory (2), Stephen Lee (3), Lam Partners Inc (4)

How Much Energy Do You Use on Your Commute To Work?

November 30, 2009 / no comments


Lighting systems have gotten vastly more efficient in the last decade. This is thanks to better bulbs, better luminaires and controls, and better lighting design – and let’s all keep working hard to make them even more efficient as technologies and design methods continue to improve. But, let’s also give ourselves a little credit for the great progress that’s already been made. For example, we’re now designing office lighting using one-sixth of the electricity typically used just 25 years ago. Imagine if we had made the same kind of progress with automobiles.

Stop reading for a minute and ask yourself: how much energy do you think you use driving to work, versus how much you use to light your personal share of your workplace? What is just the rough proportion you would guess? Let’s put some numbers to that:

Let’s say you drive a new car at the US average of 16 miles per day each way, and you average the current federal standard, 27.5 miles per gallon. That consumes a bit over a gallon of gas per day.

The same amount of fuel oil, burned in a typical power plant and distributed to your building through the grid, at an overall efficiency of 30%, will generate 14 kilowatt-hours. If you work in a 200-square-foot office and your workspace lighting power conforms to current ASHRAE standards, that gallon or so of gas will light your workspace for over 65 hours. Or, to put it another way, the fuel you use getting to work each day will light, for ten hours, not just your 200 square feet but actually 1,300 square feet – enough space for you and half a dozen friends.

How is that possible? Well, for one thing, when you stomp the accelerator on your base four-cylinder Accord (177 horsepower), in electrical terms your modest sedan is generating over 130,000 watts, and it’s doing it inefficiently. At that rate, it would take you less than 60 seconds to burn up enough fuel to light your workspace for ten hours.


Actually, our estimate is very conservative. If we get more realistic and factor in the inefficiency of refining and transporting gasoline, and we recognize that new buildings are required to have motion sensors to turn your lights off when you don’t need them, and we also recognize that the average American commuter vehicle doesn’t average anywhere close to 27.5 mpg (okay, and maybe your office is less than 200 square feet), we can come closer to a realistic answer to our initial question. And that answer is that if your workplace meets today’s lighting energy standard, your commute likely uses at least ten times as much fossil fuel as your workspace lighting each day.

So, how did you do on your guess?

Photo Credits: Skippyjon (1), MadMarv00 (2)

Solar Decathlon: Not So Sunny, But Full of Energy!

October 19, 2009 / no comments


Interior honeycomb shades provide privacy and additional insulation, and are a part of the nighttime ambient lighting system in Team Boston's house.

I was fortunate to be able to spend the weekend visiting the Solar Decathlon houses on the Mall in Washington, D.C. (see the Solar Decathlon website and Amber’s last blog article “Curious” About Sustainable Design?).

Miserable weather meant that the houses weren’t generating much electricity, but the energy produced by the students attracted many people like me willing to stand in long lines in the rain and mud to see their work. I was impressed by the sheer immensity of what the students had accomplished (none more so than the Lam-sponsored Team Boston!) and the many ways in which each team solved the same sets of design problems. It was fascinating to see how they balanced the tensions between having to make a highly efficient house that also functions well, would be a nice place to live in, and is beautiful. You could see the compromises: the house that was super-insulated but didn’t have many windows, or the house with large south-facing windows but no architecturally integrated shading to block the summer sun (perhaps because it would have violated the purity of the architecture) – or the house that kept the lighting energy so low that the lighting quality suffered.


Team Boston's southern façade featured an integrated shading overhang and innovative roll-up exterior louvers for no summer solar heat gain.

But the thing that struck me most about the competition was not something I saw on the Mall, but an entry in Thursday’s Daily Journal on the Solar Decathlon website. In describing the winners of the Lighting Design competition, it said: “A Minnesota team member commented that their goal was to use only 500 watts (or the equivalent of five incandescent light bulbs) to light the entire house”. Now, I appreciate the attempt to make the information accessible to the average consumer, but this comment is so telling about the incorrect way that the world considers lighting energy efficiency.


This type of vanity mirror seen in Penn State's bathroom showed up in a few other houses, too. Love the skylights!

The Solar Decathlon is a contest that measures (among many things) energy-efficiency, not total watts. Energy is Watts x Time (see my blog article Fight the Power! ) So I could have 2,000 watts of total lighting in my Solar Decathlon house, but if I only needed to turn some of it on for a small amount of time each day, I could use less energy than a house with 200 watts of total lighting that had to have all the lights on most of the time. If they only measured watts at the Solar Decathlon, then all they’d need to do is hook up the houses to a meter, make them turn on every system and appliance, and the house with the lowest wattage would be the winner. Well, that would be easy – but it would be dumb. So why, then, do we talk about lighting performance this way?!

So there I was on Saturday in one of the houses and a charming student tells us that all their lighting uses only 200 watts. Sigh. And then later that afternoon, in another house a student tells us how their LED fixtures use just 3 watts each. Arrgghh. So OK, we’ve done a bad job educating our students about how to measure lighting energy efficiency, but this also brings up another timely issue: lighting quality. What if you only use 200 watts but lighting quality is poor?


Finelite's LED task lights provide great bedtime reading lights for Team Boston.

And then, as expected, the LEDs were everywhere along with the hype. Several houses proclaimed that all their lighting was LED, as if just saying that indicates some special level of energy efficiency. And of course, as we were told at one house, “LEDs are seven times more efficient than an incandescent light”, when realistically they are maybe half that. Where do they get this stuff? And it’s not just efficiency misinformation, but the lighting quality issue too. Far too often, the LED sources that I observed were glary and had a ghoulish cool color. If the Solar Decathlon is a predictor of trends in residential lighting, then we might conclude that we have a lot of glare in our future.

Another comment I overheard that I thought was telling went something like this, from a gentleman standing below one of those glary LED accent lights: “Gee, if we could only get LEDs that were good for ambient lighting”. I almost went up to him and said, “You have a much better source already – linear fluorescent – twice as efficacious as LED, and much less expensive.” But I kept my mouth shut and wandered out into the rain and mud thinking that we Lighting Designers have to do a much better job educating students and the world about how to achieve true lighting energy efficiency and lighting quality.


Some serious lighting bling from Team Germany.

Photos Credit: Glenn Heinmiller / Lam Partners Inc