Lighting of exterior environments not only provides for safe navigation during hours of darkness, but can reveal design elements, both built and natural, that are lost in daylight, returning delight to the hours without sun. With all of our energy focused on lighting the ground, the importance of vertical illumination is getting lost in the darkness.

Early versions of LEED SS Credit 8 (Light Pollution Reduction), with stringent requirements to limit all light above the horizontal plane with the exception of very low-brightness fixtures, was an effort to push dark-sky agendas forward without acknowledging what a well-lighted exterior environment actually requires, or what it contributes to the urban environment. Downlight with sufficient uniformity can facilitate movement across plazas and walkways, but where are people headed? Lighted pavement alone can provide orientation only without end or destination.

While obscuration of the heavens through urban sky glow is one of the most unfortunate results of the urbanization and industrialization of our planet, the metrics for nocturnal illumination cannot be based upon the assumption that the primary task of humans in an urban environment is to go and gaze at stars. Even when these standards are met, the results can still have a negative impact: a modestly lighted parking lot with light-colored concrete pavement lit to the minimum IES recommendations, using only cut-off fixtures, can substantially degrade a dark residential environment if that pavement is within view of residences – and the reflected light from the pavement is going into the sky, even though the fixture itself does not emit light above horizontal. (This is a great opportunity to advocate for tree cover – not only does it provide parking lots with cooling shade during the summer and soften their appearance during the day, but it blocks reflected light from trespassing upwards! That’s not accounted for in the requirements).

The Lighting Research Center at Rensselaer Polytechnic Institute has developed a metric for evaluating and designing exterior lighted environments, known as Outdoor Site-Lighting Performance (OSP), that accurately documents the effect of electric illumination on a project. OSP acknowledges that glare, light trespass beyond the physical limits of the site, and sky glow are all important factors that warrant consideration. However, by using modeling tools that measure the amount of uplight trespassing off the site – not only light emitted by fixtures, but also the reflected light off of surfaces such as the parking lot mentioned above – a more realistic picture of the lighting effect can be examined. Similarly, current and future versions of LEED SS Credit 8 do allow for some amount of uplight in the urban environment.

What about projects where reliance on cut-off downlight fixtures is not a good fit architecturally? Can they still meet the intent of a sensitively lighted nighttime environment? Lam Partners’ Hermann Park Lake Plaza project avoides pole-mounted fixtures, equipment that is, in effect, prescribed by LEED and other dark-sky guidelines. Determined not to use pole-mounted lighting along the water’s edge to avoid distracting reflections in the water, the designers devised a fully integrated approach. One-watt LED button steplights illuminate and guide, tracing the arc of steps around the lake; ground-recessed ceramic metal halide tree uplights create a welcoming border.

The graceful composition remains uncluttered by hardware, focusing solely on form and line. The arrangement is serene and contemplative in early evening, then emerges dazzling and energetic as night descends. Because awakening the appearance of surfaces and landscape forms was critical to attracting visitors after dark while fostering safety and security, tree trunks and wall surfaces are boldly illuminated.

The team deliberately relinquished the LEED light pollution credit (although the project did achieve LEED status), and yet, the uplit trees are magical during nighttime strolls. As darkness conceals architectural stonework, the wooded procession comes to life through light. From across the lake, the trees form an illuminated horizon, and indirectly lighted walls form the edges of this exterior room.

Photo Credits: Anton Grassl / Esto (1), Walmart Stores (2), Overland Partners (3, 4)

While LED technology has been the darling of fixture designers, linear fluorescent lamp and ballast manufacturers have been continuing to develop a diverse range of products that round out a comprehensive toolbox for sustainable design. In addition to providing smooth light output, high color rendering, a variety of color temperature options, and good value pricing, linear fluorescent lamp-life has slowly been increasing, bringing it in line with the rated life claims of LED systems.

Are LEDS really the best option for a light source with an extended rated life? Rated life of white light LED systems currently hovers around 50,000 hours. Of course, that exciting number needs to have IES standard LM-79-2008 and/or LM-80-2008 testing to give it credibility – and LED life is dependent on thermal management, meaning that long life can be compromised by excessive heat being trapped at the diodes.

Meanwhile, lamp manufacturers are introducing new T5 and T8 fluorescent lamps with similarly extended lifespans. Newer T8 lamps on instant-start ballasts can last as long as LEDs, or, with program-start ballasts, even 55,000 hours.

However, one thing the LED has done for fluorescent technology is reinforce the importance of the entire lighting system, in this case bringing the combination of lamp, ballast, and controls to the forefront. In linear fluorescent fixtures, it is the total package – lamp, ballast, and system efficiency – that counts. A common myth persists that T5 and T5HO lamps are more efficient than T8 because they’re a newer format, but in reality T8 lamps win the race, consistently offering better efficacy (light output, or lumens per watt).

Standard-output 28-watt T5 lamps produce around 2,900 lumens with a connected load of 34 watts (85 lumens per watt); high-output 54-watt T5HO lamps produce 5,000 lumens for 62 watts (81 lumens per watt). In contrast, a 32-watt T8 lamp with 3100 lumens on a high-efficiency ballast (0.88 ballast factor ballast) offers 28 watts – 97 lumens per watt.

T5 and T5HO are still priced at two to three times the cost of T8 lamps. The real potential of T5 and T5HO lamps is that their smaller diameter allows better optical control, resulting in better reflector design, smaller fixture profiles using less material, and the opportunity for more efficient photometric performance.

To use T8 lamps successfully, there are lots of options to keep in mind. Four-foot T8 lamps come in many varieties: F32T8, F28T8, and F25T8 which allows for the design of tailored systems, with light levels and power densities to suit a project’s needs. But, should you need a controllable system that requires dimming, then the F32T8 in most cases is the only lamp that dimming ballasts want to work with (although ballast manufacturers are working on products to fill this gap).

Take charge and specify ballasts to write a better energy story. High-efficiency ballasts can result in higher system efficacy, using less power, but they need to be identified in fixture specifications in order to be provided. Otherwise you will end up with generic electronic ballasts (GEB) at the manufacturer’s discretion. High-efficiency, high-ballast-factor ballasts can over-drive T8 lamps to produce more light when needed, within allowable power-density criteria, without compromising rated lamp-life. This option is helpful in situations where one lamp is not quite enough light, but a project can’t allow the power density of adding a second lamp. When one lamp is too much, low-ballast-factor ballasts with high-efficacy lamps can provide a cost-effective continuous glowing cove, such as those used at the University of Chicago’s Gordon Center for Integrative Science, where a glow was desired to create a lantern-like effect.

High/low ballasts offer cost-effective switching options for meeting code requirements when the budget can’t afford a dimming system. However, care should be taken to determine if the 50% power level of this type of ballast delivers light levels appropriate for the space – otherwise the lights will always be switched to full output by the users.

Dimming ballasts save energy, and have been finding their way onto more mainstream projects (to support daylight-responsive dimming, or lower light levels during classroom projection), but the reality is that at full power, dimmable ballasts consume more energy than a standard high-efficiency ballast. There is a campaign for code criteria to recognize that power consumption over time is a more accurate way to document power and energy savings than connected load. Until that happens, dimmed fluorescent lamps use little energy, but in power-density calculations, they still exact a premium in terms of connected load.

Photo Credits: Arria Belli (tortoise), Polandeze (hare), Anton Grassl/Esto (project)

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.

Post-Script

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

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)

Integrated LED steplights create a processional approach to the plaza and reinforce the bridge’s architectural rhythm.

What happens when a heavily worn piece of an urban park gets a little well-deserved attention? And what role does lighting play in all of this?

Newly renovated Lake Plaza is the crown jewel in Houston’s popular Hermann Park. Run by the Hermann Park Conservancy, a non-profit citizens’ organization, in partnership with the City, this project has attained LEED certification through energy efficiency and sensitive restoration of landscape, as well as comprehensive site water management.

New train, new station, open for business.

A new main station for the park’s miniature train railroad, a gift shop, pedestrian bridge, pedal-boat rental, café, and service buildings all support recreation and rejuvenation in the heart of the city. While the plaza is used often during the day as a staging area for school groups attending the zoo, until the renovation, it had languished at night, despite the plaza’s proximity to the Miller Outdoor Theatre and its quarter of a million annual visitors.

The existing train pavilion prior to renovation.

Lighting guides and invites movement, making visual and architectural connections. Existing pathway lighting in Hermann Park relied upon historic “acorn” metal halide post-top lanterns. While well-designed historic lanterns can work well, many of the park’s fixtures had been installed in a piecemeal fashion, and they’d been over-lamped in a well-intended attempt to increase the sense of security. The layout of the lanterns did not provide the necessary visual connection from the Miller Theatre to the plaza, and existing lanterns in the plaza were overly bright, dominating the landscape (the eye always goes to the brightest thing in the line of view). It actually created the perception of less light because distracting glare constricted visitors’ pupils.

The gift shop by day: an airy structure that relates nicely with the wooded surroundings.

The design team chose to rework the plaza without the existing lanterns, and relocated them along the winding paths, where trees could mitigate their brightness, restoring the visual connection of the pathways to the rest of the park.

At night, the illuminated pavilions take on a different character and anchor the park’s destination points.

Illuminated, not by lanterns, but by the landscape and buildings surrounding it, the plaza beckons. Transformed at night into a composition of glowing pavilions, these structures create a welcoming destination and backdrop for evening strolls. Exactingly integrated compact fluorescent uplight sconces give the structures a fixtureless appearance, revealing finely crafted architectural details that are shaded during the day.

Tree uplights highlight rhythm and textures, while LED steplights reinforce the stepped form of the water’s edge.

Photo Credits: Overland Partners, except #3 by Lam Partners

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)