WELL Building Standard focus on maintaining healthy circadian lighting stimulus

Many in the building design and construction field are familiar with the LEED standard with its focus on environmental conservation and energy efficiency. Lighting efficiency and daylighting has played a significant role in gaining points through this well recognized system.

Now, the WELL Building Standard goes farther in addressing how buildings affect the health and wellness of its occupants. The contribution daylight and electric light and outdoor views are all considered, as is the quantity of light needed during the daytime hours to affect circadian stimulus.

In other words, it is not acceptable to gain efficiency by underlighting spaces occupied by people during daytime hours. While this was never the intent of reduced lighting power densities (LPD) there has been a tendency to reduce illuminance requirements (in footcandles) in some environments like schools mainly to save energy.

Although sophisticated white-tunable light systems are being promoted by some lighting manufacturers, there are also simpler ways to achieve the lighting objectives of the WELL Standard. Yes, rooms will need to have the potential for higher light levels, but dimming systems that do not create noticeable flicker become essential.

I refer you to the following article published by the Illuminating Engineering Society that goes a bit farther in describing differences between WELL and LEED related to lighting requirements.


Letter to a lighting efficiency program administrator

Dear Sir,

While I will continue to do lighting retrofits, there seems to be little incentive out there for participation in the EVT Lighting Designer program.   My lighting design practice, while using the most energy efficient lighting systems, now focuses on saving customers money on lighting product costs over more typical spec methods.   Did you know that currently almost all commercial lighting specs in VT are done by the manufacturers reps?   "or equal" is used by electrical engineers and architects- with the unintended effect of allowing lower cost, typically lower quality products to be substituted by competing rep agencies.  This leads to "a race to the bottom" in lighting quality.  Unfortunately, few engineers and architects understand enough about lighting to prevent this.    Project owners are the losers, as the contractors and suppliers enjoy sizable markups on inferior products.

I save customers money by eliminating the high markups, and specifying and supplying the right products to meet the client's needs at a fair price.  Because the contractor does not see the cost of the lighting fixtures, this also saves on installation cost.  Its typical for electricians to use 2x the fixture cost for their installed cost, which for higher quality products can be too much.

The focus of more of my projects now is on ensuring that my clients benefit not only with energy savings, but also with quality lighting designed to ensure health and wellness. Circadian stimulus is a key health component as determined by the Lighting Research Center at RPI and international lighting agencies.   Some energy retrofits have reduced light levels to the point that the spaces can have a negative impact on daylong occupants.  Others were overlighted, and then rely on dimming to reach proper light levels- sometimes resulting in noticeable flicker from low cost drivers.    I have seen a number of retrofits using magnetic LED strip that are severely underlit, as well as schools which have been delamped to the point that learning is affected.   I'd like to help address these issues, but where does one begin?

If you don't have resources available to assist in these types of projects, I quite understand, as Health and wellness are not part of EVT's goals.

Donna Leban, AIA LC

Light and Health Video Series

To learn about circadian lighting and your health, check out the new Lighting and Health Video Series from the LIghting Research Center at Rensselaer Polytechnic Institute (RPI) in Troy, NY. Its a step by step explanation about why we need to be mindful about the effect of light on our sleep.

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Lighting for Human Needs: Where does Lighting for Health fit in?

This could be a great topic for a philosophical discussion or a full-day training session.  Rather than addressing the question scientifically or even as a lighting designer/architect, I will simply ask:  What does the average worker understands about their own lighting needs? 

These are my guesses, although I’m sure some may see priorities differently. 

1.       Need to find the way.

2.       Ability to do work.

3.       Understanding the time of day, and how this affects one’s schedule.

4.       Need for connection to nature, with daylight and views being a major factor.

5.       Psychological need for comfort and support with ability to vary lighting.

Assuming I have correctly tuned into the psyche of the average American (other cultures may rank these differently) it would appear that the health and wellness aspects of lighting are not invisible to the average person.  Based on buildings that most people work in, however, it seems that only the top two are common to nearly all buildings.  Office buildings usually have views to the outside, but these may not be universally accessible to all who work there.  With hermitically sealed windows, the connection to nature is rather limited. 

Psychological and lighting needs vary throughout the work day.  It follows that having the ability to dim and raise the light level or even change the warmth or coolness of the light color would be important if more people realized that such features can be achievable with LED lighting.  

Employees are the most valuable resource in an office building, so logic would tell us that rather than designing and retrofitting lighting mainly for energy efficiency reasons, we should instead be looking to retrofit worker occupied buildings to dimmable and even white-tunable LED light to ensure that we support and nurture the best workforce.  

Recall that in the economics of the workplace:

1.       That $3/square foot (sf) of the cost of a business office is for utilities to run the building.

2.       That $30/sf of the cost of the business is for the real estate and infrastructure cost.

3.       That $300/sf of the cost of running a business is the employees and their benefits which include healthcare and sick time. 

A stressful work environment, exacerbated by a glary lighting system with no manual controls is not conducive to a health work environment.   It would follow that understanding the effect that lighting has on our health and well-being, we also would want our workplaces designed to provide more than adequate illuminance for way finding and performance of work tasks.  And yet, utility costs are the factors driving many lighting retrofits.

Isn’t it time to reevaluate?    

Beating the winter blues with light

Do you ever think about what you can do to beat the winter blues?  Some “snow birds” head south for the winter, assuming that warmer weather is the solution.   As a not-yet-retired lighting designer and architect living in Vermont, I’m looking for a local, less costly option.  Besides, I like snow!

I know from research being conducted at the University of Vermont Medical Center (UVMC) that Seasonal Affective Disorder (SAD) is prevalent in women but also men during long winters in northern climates.   SAD has been recognized as an official medical diagnosis since the early 1980’s.  This is also roughly the time when special retinal eye cells were discovered that had nothing to do with vision, but were associated with melatonin production and the setting of the body’s circadian clock.   The two topics are related, although there are factors other than exposure to adequate light in determining one’s susceptibility to SAD.

Fortunately, I do not suffer from SAD.  I do, however, recognize a loss of energy and motivation starting around November of every year and ending as the last winter snow banks disappear.  This less severe form of “winter blues” is very common.  Most people are able to cope with it by getting outdoors- whether it is sunny or not- and getting a sufficient amount of exercise.  This does work for me much of the time, but it takes effort when the weather turns nasty. 

Researchers at Renssallaer Polytechnic Institute’s Lighting Research Center (RPI-LRC) are showing how sufficient amounts of artificial lighting can be used to affect a response similar to direct exposure to sunlight.   How much light?  That would be another great blog topic!   Remember, more light alone is not necessarily sufficient to treat SAD, but can be effective in combating the more common effects of reduced winter light.  You may have heard the term “human-centric lighting” to describe designing spaces with the right amount and color of light from morning to night.  The concept is likely going to gain in popularity as these changes are enabled by highly effective (and efficient) LED lighting and control technologies.

The magic of light on a winter’s day- it can chase away the blues if you surround yourself with it.

The magic of light on a winter’s day- it can chase away the blues if you surround yourself with it.

It is certainly the case that the combined daylight and artificial daytime light we get in our homes, places of work and play help affect not only our ability to get a good night’s sleep, but our general outlook during the wintertime as well.   Does this surprise anyone, or does it sound obvious?   

So, can we beat the winter blues with light?   Yep.  My next blog topics will focus on lighting that can help prepare ourselves to avoid next winter’s blues.  The good news is that some options do not involve spending money.   For those who must be indoors much of the time, creative use of existing light sources can be part of the solution.  And, for those who like to be on the cutting edge of technology, we’ll consider the growing options that are already out there.       

If you are in any way connected with K-12 or higher education, I would love to hear from you about lighting in classrooms and academic settings.  Your school could become a case study for combining the best of lighting science and energy efficiency.   Just email me at info@lightspacedesign.biz  

What is Circadian Lighting? Why is it important?

When we adopt good daylighting practices in a building design, we are incorporating circadian lighting.  Circadian lighting, by definition, is ambient light that simulates the color spectrum and intensity of daylight.   Of course, we don’t live in a climate where every day is perfectly sunny.  We also live on a planet where there are many more hours of available daylight in the summer than in the winter, unless you live in the tropics. 

Factoid:  Burlington, VT has an average of 58 sunny days (up to 30% cloud cover) and 101 partly sunny days (40-70% cloud cover during the daytime).   Over the year, we get 49% of the potential available sunshine.

Suffice it to say that circadian lighting in buildings is more important in some climates and parts of the world than others.  Or is it?   Very few buildings have critical access to daylight in every occupied space during the day.  So, anyone who spends a majority of their time indoors is likely not experiencing anything close to circadian lighting unless it is brightly lighted (more than 50 footcandles) with neutral to cool color light in the late morning hours.   Unless you live in a glass house, the amount of natural daylight we experience when indoors is usually not sufficient to provide “circadian stimulus”.

Circadian stimulus.  This is a new metric created by researchers at Renssaellaer Polytechnic Institute (RPI).  It is a calculated measurement that allows us to describe the amount and color characteristics of light needed for effective circadian light exposure in architectural spaces.   It is important to note that effective circadian stimulus can be achieved with either daylight or artificial light, or a combination of the two.  While the quantity and color spectrum of the light is important in terms of circadian stimulus, the timing of exposure is critical.  Late morning exposure to light is critical to regular resetting of circadian cycles.  Late day exposure to bright, cool color light is detrimental to these same cycles.  This has to do with the regulation of the body’s own production or suppression of melatonin.  

Why is melatonin production and circadian stimulus important for human health?  Light is the main stimulus that helps reset the body’s circadian rhythm.  If disruption occurs to this 24-hr cycle, we experience detrimental effects to physiological functions, neurobehavioral performance, and sleep.  This is why we need to pay more attention to not only the kind of light we are using, but also when we are experiencing it. 

An excellent example of daylight and artificial lighting combined for morning circadian stimulus.    Lumenpulse image credit.

An excellent example of daylight and artificial lighting combined for morning circadian stimulus. Lumenpulse image credit.

Uncovering the Secrets of Commercial Fixture Pricing

Here’s a topic that architects and engineers, and anyone who’s ever specified or purchased commercial lighting products can relate to.

Why is it so difficult to get pricing on commercial grade products?  When designing a project that needs to be brought in on-budget, it’ impossible sometimes to know how much the desired product will cost.  The lighting industry persists in using an antiquated, multi-layered system of sale and delivery that ensures that new, innovative products are priced higher to recover development costs, at least until others produce a similar product.

There is some logic involved, although the logic is based onseveral confounding issues:

  1. Many contractors and suppliers persist in demanding the lowest cost products, since they don’t think the customer cares about quality and performance.
  2. Mfrs of new and higher quality products resist publicizing prices to avoid others undercutting their price and taking away market share.
  3. Manufacturers often copy each other’s products.  Even though the products may look similar, they may not be equal in quality and performance.   It sometimes takes a knowledgeable lighting pro to tell the difference, at least before the fixture is installed and the difference may be more obvious.
  4. Once a type of product is manufactured by enough companies, it becomes a commodity with a typical price point, and these products become ubiquitous.

I am often called to look at lighting installations where inexpensive, but energy efficient products were installed in locations that demanded a better shielded and better looking luminaire.   Sometimes these products were installed for little or no cost by an energy service company or efficiency program.

As the old addage goes, “You get what you pay for”.   Paying a little more often gets you a lot more in benefits, and an installation you’ll be happy with for many years.

LED Outdoor Lighting Comes of Age


LED streetlighting.  An easy way for utilities and communities to save on electrical consumption and $$$’s.

This is the reason that of all LED uses, outdoor lighting took off the fastest.  Many of the luminaires are made in the USA – so federal funding from ARRA (American Relief and Recovery Act) were well spent by many communities on their streetlighting facilities.

Benefits include:

  • Significantly reduced maintenance
  • One for one replacements save roughly half the energy used
  • LED directional light source places the light where it is needed.
  • Wide light distribution provides lower contrast than other light sources, which improves safety.
  • Costs continue to come down as higher efficacy LED sources are developed, and fixture design improves.

Light/Space/Design is currently working with Lebanon, New Hampshire in upgrading its streetlighting and outdoor area lighting.   An open public informational meeting is planned for June 19th.  Contact Lebanon Town Hall for details.

Using Solatubes to add top lighting in classrooms


This post was inspired by a story recently told to me from a friend who is working with architects in the renovation of a school building.   When asked to provide daylighting in classrooms that otherwise had no windows, the architect suggested solar tubes, otherwise known as SDD’s for Solar Delivery Devices.  Good idea!

However, these classrooms where on the first floor of a 2-story building, and only one SDD was proposed for each classroom.  This would not work out very well.


Rather than spend rather a lot of money going this route, there are excellent ways of providing simulated daylight in interior spaces.  Since the diffusers from the solar tubes look a lot like light fixtures anyway, one might even take the simulated ones for real.

Here are two photos of other architect’s projects where SDD’s were well utilized.

Designing with new light sources, where to start?

A lighting blog for designers and as well as those who enjoy shaping their environment.  Is there room in the blogosphere for such a thing?   Do business and home owners want to know more about lighting beyond the energy savings potential of CFL’s and LED’s?

When I go to retail lighting stores and big box home stores, and even to wholesale lighting distributors, it seems like lots of folks are scratching their heads about what seem to be expensive choices in new lighting sources.   Why is there such a difference in cost from the old standards which may no longer be available.  And where can you even get new products that you may see in magazines but are not available in local stores?

Yes, energy efficiency is important.  Even more important, however, is how lighting allows us to feel and perform as we occupy a space.  How does the color of light affect the mood?  How do lighting controls allow us to adapt our environment to our needs?   Can one make up for a lack of daylight with artificial lighting, and still have a space that feels right?

Its a new world of lighting out there.  Lets make this a great meeting place to talk about it.

DJ -The Lighting Lionness