Blog Post

More Heat Than Light: Six Wrong Ways to Daylight a Building

Thanks to LEED and other standards, everyone's doing daylighting now--but not everyone is getting it right. Here's how it goes wrong--and how to do it right.

The Seattle Central Library has been lauded for its daylighting features, but many library patrons and staff have trouble with overheating and glare at workstations like these. Photo: Nadav Malin

You can't turn around these days without seeing a case study that mentions the use of natural daylight to help save energy and enhance the well-being and productivity of occupants--especially students and employees.

Unfortunately, almost as common are horror stories of fabulous green buildings that make their occupants miserable. Here at BuildingGreen, we've heard a tale or three about librarians wearing sun visors on the job, office workers using open umbrellas as parasols in their cubicles, and schoolteachers in award-winning buildings who keep the blinds closed constantly.

For our recent EBN feature article, "Doing Daylighting Right," we collected some of these stories, along with some really great tips from leading daylighting experts who have accomplished successful daylighting designs resulting in happy, productive building occupants and lower energy bills. But in case you're interested in how to get your daylighting design just wrong, we've put together six key tips for you below.

Overglaze it

If a little daylight is a good thing, then an all-glass building must be the ultimate, right?

Well, not so much. True design for daylighting involves intentional use of carefully chosen glazing. "There's been lots of work done by lots of people that shows that the more glass you have, the more energy you use," says Fiona Cousins, P.E., principal at Arup in New York. A 30%–40% window-to-wall ratio should provide plenty of daylight if the glass is located in the right place--high up to optimize penetration deeper into the space--Cousins adds. But if you want to forego the potential energy savings and make occupants as uncomfortable as possible, 100% curtainwall is definitely the way to go.

In seriousness, judicious use of high-performance curtainwall can be part of an energy-efficient building that still has the dazzle many designers and building owners prefer. Our research director Jennifer Atlee just put together some great guidance on standout curtainwall systems from GreenSpec and how to use curtainwalls with care.


BuildingGreen relies on our premium members, not on advertisers. Help make our work possible.

See membership options »

Ignore orientation

Don't let little details like where the sun rises and sets get in the way! Looking for "connection with nature"? How about full-in-the-face glare that really gets our building occupants noticing the awesome power and life-giving force of the sun? Seeing their computer screens would only detract from this goal.

On the other hand, if you wanted to make it possible for people to work and study comfortably in their buildings, you'd end up with a lot of untidy asymmetry: shading systems that are different on the south than they are on the east or west; glazing that's "tuned" based on orientation; and clerestories or roof monitors that face north and south, never east and west.

Emphasize views and call it daylighting anyway

One of the most aesthetically pleasing ways to get daylighting wrong is to emphasize expansive views and then assume that any window area brings in useful daylight, even if the window extends all the way to the floor or is on the west orientation of the building.

A more thoughtful, occupant-focused daylighting design would separate the view windows from the daylighting windows and ensure that separate shading can be used for each. It would also provide solar shades for view windows to preserve the views while minimizing glare, relying on sophisticated modeling software to help determine the correct openness factor for such devices.

Skip the automated controls (or skimp on commissioning)

Studies have shown time and time again that you're more likely to realize energy savings from daylighting if an automatic daylight dimming system is installed in the building. One of the easiest ways to get daylighting wrong is to skip this system altogether in order to help your clients save money--or, failing that, to value-engineer commissioning of the daylight dimming system out of the budget.

If you would instead prefer to provide a workable daylighting system that will eventually pay for itself, experts agree that you'll fight tooth and nail to keep the automated controls in, and you'll work closely with the control system manufacturer, the commissioning agent, and the building owner to ensure that the system works exactly the way it should. This goes for automated shading as well.

Bump up the contrast

One of the lesser-known ways to spoil a well-designed daylighting system is through interior design. Because daylight modeling depends heavily on surface reflectance, a bold color palette can be a key part of darkening rooms, ensuring people turn on the lights more often and waste as much energy on electric lighting during daylight hours as possible. High contrast can also cause eyestrain--an emerging strategy for maximizing occupant discomfort, particularly in schools.

The lower panels in this office at the Yale Sculpture Building are filled with light-diffusing silica aerogel to provide insulation while bringing in daylight. Despite their translucence, the panels had to be covered with fiberboard in some rooms to control daylight entry. Photo: Alex Wilson

Keep occupants out of the loop

Unlike most other aspects of design, the success of daylighting depends heavily on occupant behavior, and occupant satisfaction is a key measure of success. There's nothing like a failure to communicate to really put the icing on the cake of poor daylighting performance. Occupants who don't know what interior lightshelves are for might stack books on them; occupants who don't understand how the lighting controls work might tape over the sensors; and occupants who aren't aware of the benefits of daylighting might just keep the blinds closed all the time.

In contrast, a project team trying to do good daylighting design will anticipate and design for occupant needs and habits--and will engage directly with building owners, managers, and occupants about how the lighting system works--in order to realize performance benefits from daylighting.

Doing daylighting right

If for some reason you're not satisfied with our six tips on how to do daylighting wrong and you're interested in more information on how to do it successfully, this month's EBN feature article takes a deeper look at the following issues and strategies:

  • The importance of integrated design
  • Preventing glare and excessive heat gain
  • Balancing electric lighting with daylight
  • Addressing cultural issues that make people turn on lights
  • Starting space planning earlier than you might be used to
  • Metrics and standards for daylighting
  • Exciting innovations in wireless lighting control systems
  • Guidance on daylighting products, such as lightshelves
  • Integrating daylight simulations with energy models
  • The importance of daylighting in everyday buildings

Published April 2, 2012

(2012, April 2). More Heat Than Light: Six Wrong Ways to Daylight a Building. Retrieved from

Add new comment

To post a comment, you need to register for a BuildingGreen Basic membership (free) or login to your existing profile.


December 26, 2016 - 5:37 am

It was really good. Thanks for the comment.

May 2, 2012 - 9:17 am

Mamun, I assume you are referring to the picture from the Seattle library? These desks are not for patrons but for library staff, and they may have been closed when the picture was taken. The points made are not about whether patrons use the library--as they most certainly do. The photo is not making any claims to the contrary. The points made are about glare and overheating at workstations. I do hope that someone will do some data collection on this building, which seems to be loved by some and hated by others. That would be the work of a master's or doctoral thesis, though, not a blog post. I did recently read an excellent dissertation on a different building by Kyle Stan Konis called "Effective Daylighting: Evaluating Daylighting Performance in the San Francisco Federal Building from the Perspective of Building Occupants." It's available here:

May 2, 2012 - 5:31 am

The researchers conveniently missed other aspect of users' perception. I have a photo that shows the the area is actually buzzing with patrons all over the place. Not a single seating appears to be empty. As seen here, I wonder when (/which day) was the photo taken! What about other days/times, when the space is full? Puns are good for Newspaper/web article, not for research. Please put out more validated information, so that we can seriously rectify the mistake of architects. Thanks.- Mamun, researcher.

April 10, 2012 - 5:25 am

Thanks Melanie- I think the problem often lies at the design stage in the EE's office- many times I have have practically begged them to at least circuit the lighting such that an alert owner might someday decide to control the lights in accordance w/ daylight. But if the lights are circuited all together with no regard to which ones might want to be off for say 17 hours a day in the summer...then it becomes very difficult to justify the controls later.

April 9, 2012 - 11:38 pm

Before the electric light was invented, and for a good while after that too, designing buildings so that daylight could enter interior spaces was a necessity. Yet despite a long history of using daylighting as a design strategy, building owners, architects, engineers and lighting designers are only just beginning to understand how to use it effectively.


April 9, 2012 - 10:55 pm

I have done a significant amount of daylight modelling and feedback to architectural design teams. I know everyone talks about what is taught in architectural shools and is common sense. Far to often I have found that from the modelling those common sense decisions turn out to be wrong, becuase not all the aspects as highlighted in this article are taken into account.
Yes the first 3 items are taught in universities, but they do not work in isolation. The facade design must consider all the aspects, and the common sense concepts work really well and can be easily applied to simple geometry. It takes a highly skilled and experienced architect to apply the design principle to complex geometries (curved facades, etc) and get it right.
Good passive design is the key to daylight and energy efficiency, automatic controls only work as long as they WORK, i.e. the maintenance problem. Once they are broken the building can be worse than a much simpler less technical building.
Situation, Local weather, Orientation, Glass Area, Glass performance, shading design, interior layout, interior finishes, effect on HVAC system, lighting control, occupant needs, access to views, glare.

April 9, 2012 - 4:23 pm

I agree with the common sense folks. I am not a believer in following idealogies. IF it makes sense and is cost effecfive then do it. IF you want to splurge a little and be ahead of things as long as it is YOUR money you want to spend then fine.
Daylighting, feng shui and all that other stuff is really just a marketing gimmick and is part of Good Design. My .02

April 6, 2012 - 4:30 pm

For those who think all this daylighting stuff is common sense, I urge you to look at the photos included with the post. In many aspects of life, what we like to call "common" sense can be surprisingly rare. There is a clear and genuine need for professionals to refresh their memories about daylighting principles.

I also want to add that the feature article referenced in this blog post goes into quite a bit more depth about each of the issues listed at the end of the post. So if you're looking for more detailed guidance, that would be a good place to start.

I'm curious what you were taught in arch school about occupants' needs and habits around daylighting.

April 6, 2012 - 10:22 am

I agree with the first comment: Aside from the controls, we covered these basic design strategies in Architecture school. And we demonstrated the concepts without the aid of computer generated shadows or modeling! Because they are such basic best- practice measures, I was surprised to see them outlined in an article meant for professionals.

April 5, 2012 - 6:43 pm

Even in Washington where temps are mild, I recently heard that many of the new "green" schools in the Pacific NW have experienced increased heating bills due to the addition of all these beautiful windows - unfortunately negating some of the other energy saving features. You offer very practical, detailed information. Proper orientation and well placed "sources of daylight" near light-colored, reflective surfaces can offer so much in bouncing light around. Even elevation of structures in relation to what's close by outside and vegitation considerations can impact light coming into a space more than people realize. Don't forget Solatube Skylights! Gathering daylight from the roof in all directions versus more limited light from windows will bring more consistent light throughout the day without the glare and without the heat gain or loss. In conjunction with with automated lighting this is a great way to go! Solatubes are Built Green and LEED Certified options for homes and commercial structures and the only brand able to travel 20 and 30 feet offering full spectrum daylight.

April 5, 2012 - 2:59 pm

Very informative article. As a lighting control manufacturer, sometimes I feel I'm the only one talking to my customers that proper daylight/electrical light control is key to most projects. It's nice to see other folks talking about the importance of such integrated system not only for energy reduction but for employee productivity.

April 4, 2012 - 7:26 am

Hi- I like the article about the 6 things done wrong, but I think it needed one more- lack of controls or use of controls in daylit spaces. I just went thru 4 airports last week and noticed in all of them some nicley daylit spaces (sunny days). Problem is every artificial light was still on! I mean all the lights that are designed for nightime! Even cove lighting along the glass! This is so bad that these brand new spaces can have this occur, I wish I knew how to affect change when I see these things. Thanks.

April 4, 2012 - 8:32 am

Tom, thanks for your comment. Skipping the automated controls (or skimping on commissioning of them) is one of the "bad daylighting strategies" already listed above. Sounds like you've witnessed that one firsthand. Thanks for the story; let us know if you find a way to alert the building owners about what you witnessed.

April 4, 2012 - 8:55 am

It's surprising this subject should even have to be discussed. It is filled with common sense, and the concepts were taught to me in architecture school at GA Tech 40 years ago.