This CE Center article is no longer eligible for receiving credits.
Providing fenestration in exterior walls is driven by a variety of factors. In some cases, it is a primary form giver in the design of a building and has certainly been the key to many approaches leading to award-winning designs. In the interest of promoting well-being and healthy environments, fenestration has also been seen as an essential component in that effort. At the same time, fenestration has been the focus of intense advancement and development to address the need for energy conservation in buildings. In this regard, bringing natural light into a building can be an energy saver by allowing artificial lighting to be switched off, as long as that natural light doesn’t overpower the interior and create glare or a light level that is too intense. On the other hand, fenestration can allow more heat loss than an insulated wall or too much heat gain from sunlight passing through the glazing, either of which could increase the need for energy to heat or cool a building. Recognizing this array of interconnected variables, manufacturers of fenestration products offer choices in how these products can be sized, specified, and assembled so that architects can select and customize their products to suit the overall design, human needs, and energy performance requirements of many different buildings. With all of these points in mind, this course will look at some of the driving forces behind incorporating fenestration into buildings, latest technologies and products available, and design approaches to help balance light, connectivity, and energy conservation.
Photo courtesy of Saint-Gobain SageGlass
Fenestration can be implemented in buildings in many different ways to achieve a design concept balanced with performance requirements for natural light, energy use, and weather resistance.
The Power of Light
Many people are attuned to the cultural sentiment for well-lit spaces, but some scientific evidence based on research indicates that increased exposure to light makes people more productive and improves their sense of well-being, therefore improving overall wellness.1 Some specific studies have also looked at particular aspects of the impact of natural light on people, such as the following.
- Biophilic design: Human beings have moved relatively quickly from spending most of our time outdoors to most recently spending up to 97 percent of our time indoors.8 Nonetheless, we still have some psychological and deep-rooted connections to things in the natural world that have been traced to the earliest days of living on terrain like meadows and the savanna.2 Recognizing these connections has become the impetus behind an effort known as biophilic design.
- Exposure to light: Exposure to natural light has been shown to play an important role in a healthy sleep/wake cycle. More specifically the rhythmic pattern of dawn, day, dusk, and night affects our inherent circadian rhythms, influencing us in physical, mental, and behavioral manners. The rhythms of light and darkness in a person’s environment are recognized by a type of receptor in our eyes, while the sun as a light source connects to our internal clocks, telling us when to wake and sleep.3,4
- Lack of light: Research has shown that a lack of exposure to light can actually make people sick. In the 1980s, U.S. software firms discovered one of the most detrimental factors to engagement and productivity of their employees was a lack of natural daylight.5 Even worse, doctors began to diagnose patients who spent too much time in artificially lit, poorly ventilated spaces with Sick Building Syndrome, a condition affecting office workers that is attributed to unhealthy or stressful factors in the working environment.6 This has been recognized in Japan in a particular way where skyscrapers and intense urban density led to the concept of “nissho-ken,” which translates to “a right to sunlight.” After a string of “sunshine suits” in the late 1960s and early 1970s, more than 300 Japanese cities adopted “sunshine hour codes,” specifying penalties that developers must pay for casting shadows. “Sunshine is essential to a comfortable life,” the court opined, “and therefore a citizen’s right to enjoy sunshine at his home should be duly protected by law.’”7
In response to the significance of daylight, then, it becomes incumbent on architects to take this into account in the interest of designing buildings that protect and promote the health and welfare of the people who occupy them. There are, of course, many different ways to meet these needs that center on “designing with light.”
Photos courtesy of Marvin Windows and Doors
The concept of “designing with light” involves the judicious use of fenestration to provide connections between the indoor parts of a building and the natural, outdoor world.
Manufactured Windows
Manufactured unit windows are a common staple of many buildings whether residential, commercial, or even institutional. As a fabricated product, they need to have their own physical integrity for internal support and durability over time. In the past, that has meant heavy frame and sash members, usually made out of wood, which reduced the size of the glazing and therefore reduced the amount of light entering through the window.
Modern buildings tend to have more windows made with narrower frames. This increases the capacity for light to pass through the windows while also offering better views.
Those views to the exterior allow a direct connection to the healthy, natural state that people experienced when they spent most of their time outdoors. This speaks to biophilic design, since it brings the feeling of being in nature into the built environment. Manny Gonzalez, FAIA, LEED AP, is principal and director at KTGY, a Los Angeles-based architecture firm. He is sensitive to this biophilic approach, saying, “The feeling of being in nature stays with you, even while inside looking at trees, a garden, or patio. Your mind may not realize it, but your body wants that feeling of getting back to nature.”
Applying this human longing for connectivity to the outdoor environment is what Gonzales and others cite as designing around natural light. “Being able to control the lighting— whether it’s the natural light that you have, the UV rays that you get through a window, visibility, or window coverings—all those things start tying together when you’re creating the proper environment,” Gonzalez adds. “If you do a good job as an architect, the resident won’t even know that they’re experiencing biophilic design. They don’t even think about it—it just feels good.”
When a building design embraces and enhances the benefits of natural sunlight through deliberate window choices that strengthen our connection to the outdoors, those much-desired feelings of well-being are the natural result. The more exposure to the outdoors and light, the better we feel because we’re more in sync with the rhythms of daylight, and therefore more in tune with nature. “All of these things tie into healthy living, the ability to get the sleep that you need, the wellness everyone is talking about trying to get,” Gonzalez says. Window manufacturers recognize this point and have responded with updated products that provide minimal sightlines with larger expanses of glass. This combination helps provide a seamless, clutter-free appearance that makes it easier to engage with the outside world through windows and doors.
Christine Marvin, director of corporate strategy and design at Marvin Windows and Doors, is among the window company executives who are working to advance this approach. “People want to feel better and live healthier lives,” she notes. “Light has a huge impact on how people feel about their home.” In regard to the latest window products available on the market that maximize light and provide cleaner, more modern looks, she adds, “This enables homeowners to achieve what they seek in their home—connection, restoration, and freeness.”
Among the features that achieve the myriad design and performance demands of windows, Marvin notes that sightlines can remain unobstructed with less than 3 inches of framing visible across window products in prefabricated and preconfigured components that save on installation time. Further, improvements in the frame design help keep interior temperatures comfortable and address energy conservation as much as improvements in glazing. Durable materials including high-density fiberglass speak to the strength and longevity of the windows, including their ability to seal against unwanted air infiltration over time.
Photos courtesy of Marvin Windows and Doors
Windows are available with narrower framing to improve sightlines with cleaner appearances to maximize the view, receive natural daylight, and provide a sense of wellness to building occupants.
Providing fenestration in exterior walls is driven by a variety of factors. In some cases, it is a primary form giver in the design of a building and has certainly been the key to many approaches leading to award-winning designs. In the interest of promoting well-being and healthy environments, fenestration has also been seen as an essential component in that effort. At the same time, fenestration has been the focus of intense advancement and development to address the need for energy conservation in buildings. In this regard, bringing natural light into a building can be an energy saver by allowing artificial lighting to be switched off, as long as that natural light doesn’t overpower the interior and create glare or a light level that is too intense. On the other hand, fenestration can allow more heat loss than an insulated wall or too much heat gain from sunlight passing through the glazing, either of which could increase the need for energy to heat or cool a building. Recognizing this array of interconnected variables, manufacturers of fenestration products offer choices in how these products can be sized, specified, and assembled so that architects can select and customize their products to suit the overall design, human needs, and energy performance requirements of many different buildings. With all of these points in mind, this course will look at some of the driving forces behind incorporating fenestration into buildings, latest technologies and products available, and design approaches to help balance light, connectivity, and energy conservation.
Photo courtesy of Saint-Gobain SageGlass
Fenestration can be implemented in buildings in many different ways to achieve a design concept balanced with performance requirements for natural light, energy use, and weather resistance.
The Power of Light
Many people are attuned to the cultural sentiment for well-lit spaces, but some scientific evidence based on research indicates that increased exposure to light makes people more productive and improves their sense of well-being, therefore improving overall wellness.1 Some specific studies have also looked at particular aspects of the impact of natural light on people, such as the following.
- Biophilic design: Human beings have moved relatively quickly from spending most of our time outdoors to most recently spending up to 97 percent of our time indoors.8 Nonetheless, we still have some psychological and deep-rooted connections to things in the natural world that have been traced to the earliest days of living on terrain like meadows and the savanna.2 Recognizing these connections has become the impetus behind an effort known as biophilic design.
- Exposure to light: Exposure to natural light has been shown to play an important role in a healthy sleep/wake cycle. More specifically the rhythmic pattern of dawn, day, dusk, and night affects our inherent circadian rhythms, influencing us in physical, mental, and behavioral manners. The rhythms of light and darkness in a person’s environment are recognized by a type of receptor in our eyes, while the sun as a light source connects to our internal clocks, telling us when to wake and sleep.3,4
- Lack of light: Research has shown that a lack of exposure to light can actually make people sick. In the 1980s, U.S. software firms discovered one of the most detrimental factors to engagement and productivity of their employees was a lack of natural daylight.5 Even worse, doctors began to diagnose patients who spent too much time in artificially lit, poorly ventilated spaces with Sick Building Syndrome, a condition affecting office workers that is attributed to unhealthy or stressful factors in the working environment.6 This has been recognized in Japan in a particular way where skyscrapers and intense urban density led to the concept of “nissho-ken,” which translates to “a right to sunlight.” After a string of “sunshine suits” in the late 1960s and early 1970s, more than 300 Japanese cities adopted “sunshine hour codes,” specifying penalties that developers must pay for casting shadows. “Sunshine is essential to a comfortable life,” the court opined, “and therefore a citizen’s right to enjoy sunshine at his home should be duly protected by law.’”7
In response to the significance of daylight, then, it becomes incumbent on architects to take this into account in the interest of designing buildings that protect and promote the health and welfare of the people who occupy them. There are, of course, many different ways to meet these needs that center on “designing with light.”
Photos courtesy of Marvin Windows and Doors
The concept of “designing with light” involves the judicious use of fenestration to provide connections between the indoor parts of a building and the natural, outdoor world.
Manufactured Windows
Manufactured unit windows are a common staple of many buildings whether residential, commercial, or even institutional. As a fabricated product, they need to have their own physical integrity for internal support and durability over time. In the past, that has meant heavy frame and sash members, usually made out of wood, which reduced the size of the glazing and therefore reduced the amount of light entering through the window.
Modern buildings tend to have more windows made with narrower frames. This increases the capacity for light to pass through the windows while also offering better views.
Those views to the exterior allow a direct connection to the healthy, natural state that people experienced when they spent most of their time outdoors. This speaks to biophilic design, since it brings the feeling of being in nature into the built environment. Manny Gonzalez, FAIA, LEED AP, is principal and director at KTGY, a Los Angeles-based architecture firm. He is sensitive to this biophilic approach, saying, “The feeling of being in nature stays with you, even while inside looking at trees, a garden, or patio. Your mind may not realize it, but your body wants that feeling of getting back to nature.”
Applying this human longing for connectivity to the outdoor environment is what Gonzales and others cite as designing around natural light. “Being able to control the lighting— whether it’s the natural light that you have, the UV rays that you get through a window, visibility, or window coverings—all those things start tying together when you’re creating the proper environment,” Gonzalez adds. “If you do a good job as an architect, the resident won’t even know that they’re experiencing biophilic design. They don’t even think about it—it just feels good.”
When a building design embraces and enhances the benefits of natural sunlight through deliberate window choices that strengthen our connection to the outdoors, those much-desired feelings of well-being are the natural result. The more exposure to the outdoors and light, the better we feel because we’re more in sync with the rhythms of daylight, and therefore more in tune with nature. “All of these things tie into healthy living, the ability to get the sleep that you need, the wellness everyone is talking about trying to get,” Gonzalez says. Window manufacturers recognize this point and have responded with updated products that provide minimal sightlines with larger expanses of glass. This combination helps provide a seamless, clutter-free appearance that makes it easier to engage with the outside world through windows and doors.
Christine Marvin, director of corporate strategy and design at Marvin Windows and Doors, is among the window company executives who are working to advance this approach. “People want to feel better and live healthier lives,” she notes. “Light has a huge impact on how people feel about their home.” In regard to the latest window products available on the market that maximize light and provide cleaner, more modern looks, she adds, “This enables homeowners to achieve what they seek in their home—connection, restoration, and freeness.”
Among the features that achieve the myriad design and performance demands of windows, Marvin notes that sightlines can remain unobstructed with less than 3 inches of framing visible across window products in prefabricated and preconfigured components that save on installation time. Further, improvements in the frame design help keep interior temperatures comfortable and address energy conservation as much as improvements in glazing. Durable materials including high-density fiberglass speak to the strength and longevity of the windows, including their ability to seal against unwanted air infiltration over time.
Photos courtesy of Marvin Windows and Doors
Windows are available with narrower framing to improve sightlines with cleaner appearances to maximize the view, receive natural daylight, and provide a sense of wellness to building occupants.
Opening Glass Walls
In some building situations, there is a design intent or a user need to provide dramatic flexibility in the use of fenestration. The fullest extent of this approach is being able to open or close large sections of wall areas completely. A product that does just that is identified as an opening glass wall that uses large, door-sized glass panels that can be readily opened or closed on demand. Like any other type of building fenestration, this system does not carry any structural load from the building but is reliant on being appropriately attached to the building and operates within a structurally supported opening.
This type of flexible fenestration has been popularly used in a wide range of building types, including restaurants, retail, hospitality, education, sports venues, office buildings, and even residential projects, both single and multifamily. In retail settings, for example, opening up the entrance makes the entire street front a welcoming door by eliminating barriers. This creates a seamless transition between the street or mall and the store, helping to attract customers inside and increasing sales. When it is time to close up for the day, the glass wall continues to showcase the interior and provides a secure, energy-efficient, transparent facade that seals tight as a dust-control measure after hours. Restaurant owners like operable glass walls because additional seating space can be readily accessible by opening up the inside to the outside. This type of system can also provide comfortable and attractive four-season outdoor dining by enclosing a covered patio.
In hotels and other hospitality projects, similar benefits exist in using an opening glass wall when a large inviting entrance into the lobby area is created, producing a memorable first impression. It is also possible to incorporate beautiful views, hotel landscaping, natural daylight, and fresh air into the registration, dining, and guest room areas when the walls are open. They can even be used as interior divisions in hotels and restaurants to allow personnel to quickly and easily incorporate or close off adjacent retail space, dining areas, bars, terraces, or meeting rooms. Similarly, office buildings may include common entry or gathering areas that seek copious amounts of natural daylight and connectivity to the outdoors. Opening glass walls are an ideal product to use in those cases since they allow unfettered connections between indoors and outdoors when opened.
While many benefits of light, air, and connectivity can come about by using opening glass walls, the true measure of performance and quality is how they perform when closed. There are a number of different manufacturers of opening glass walls, and they do not all perform the same, so it is necessary to pay attention to the details of their fabrication and request independent test results. The first key performance attribute to look at is the energy-conservation capability of a product. When the opening glass wall is closed, the overall R-value or U-factor of the unit should be known based on verified testing. The unit should also be tested for air infiltration with the capability of using built-in seals and gaskets to assure that air leakage is reduced to meet standards for energy-efficient design. All of this will not only help improve the energy performance of the building, but it will also help the occupants be more comfortable by keeping the cold on the outside while maintaining warmth inside—even right up against the glass and frames.
In addition to energy performance, weather resistance is needed, as in all fenestration products, to seal out wind, rain, and other weather conditions. Manufacturers use a variety of specialized seals and panel designs to provide humidity and moisture control, with some reaching a very high level of performance in this regard. A key component is the design of the sill that the opening glass wall rests on to assure that it completely resists wind-driven water from entering the building. In some cases, the design needs account for extreme weather, such as hurricanes, tornadoes, or other similar extreme weather events. In that regard, at least one manufacturer uses moving structural posts to provide unparalleled strength in units that are approved by Miami-Dade County with AAMA hurricane ratings.
In addition to these factors, a performance review should include attention to details such as multipoint locking entry doors that may be equipped with tamper-resistant locking rods between panels to ensure they meet or exceed forced-entry testing for commercial-grade door panels. It may also include built-in adjustment and compensation points to ensure continued ease of operation if any building settling occurs. When closed, the opening glass walls should dampen sound transmission for the desired acoustical performance needed in the building.
Matt Thomas is the marketing manager of NanaWall Systems and says, “Large openings are easy to design, but it’s the performance when closed that matters most. Glass walls must perform during all seasons of the year—especially opening glass walls. Their performance is critical.” Since virtually all of these products involve some sort of custom design at the direction of the architect, Thomas goes on to say, “For us as a manufacturer, it’s important to supply a product that enables the architect to fulfill their vision but also to provide a product that lasts. These performance points are usually as important to the architect as the aesthetic appearance since we provide the product they are specifying on behalf of their client.” In the end, it is the building owner and users that benefit most from these opening glass wall systems in terms of design, connectivity, light, ventilation, and performance.
Photos courtesy of NanaWall Sytems
Opening glass walls provide the opportunity for large, controllable fenestration that can open up directly to the outdoors or be closed up tight to provide an energy-conserving enclosure.
Dynamic Glazing
The multiple benefits of natural daylight and views have been well documented, but there is another aspect of fenestration design that needs to be addressed, namely the design challenge of light balance and control, which is critical to a successful outcome. In this regard, it is important to recognize that daylighting has direct impacts on things beyond the provision of natural light and views. If the light is too intense or creates too much of a contrast within a space, then it will be regarded as uncomfortable glare that is not welcome by the occupants. The usual response is to find a way to cover or shade the offending opening, which will likely contradict the design intent and functionality of the fenestration if it is not part of the original design. Similarly, the constant exposure of materials and finishes to sunlight can also cause colors to fade and materials to break down.
One of the biggest issues in balancing the amount of natural light with the building is the fact that the solar light passing through fenestration also brings solar heat with it—all year long. That solar heat may be welcome in cool weather, contributing to greater occupant comfort while using less purchased energy for a mechanical heating system. However, during warm weather or in buildings that tend to require more cooling than heating, increased daylighting can bring an unintended penalty of too much solar heating, thus making people less comfortable, causing more air-conditioning to run, and consuming more energy—all the opposite of many original design intentions.
The key to good daylighting design in buildings, then, is to find ways to maximize the positive benefits of daylight and solar gain while minimizing the negative possibilities of glare, fading, and energy penalties. Conventional design approaches to find that balance have included some very specific strategies, most of which involve additional building components. For fenestration located on the east and west sides of a building, for example, horizontal or vertical louvers can be applied to the building either on the internal or external side of the wall. External louvers are usually fixed in place and fabricated out of aluminum or other durable materials. Internal louvers may include single or multiple light shelves, adjustable blinds, or similar products. Any of these can reflect light into the space and cause it to disperse; however, they will likely interfere with the view out of the windows. For fenestration that is facing south, horizontal light shelves or horizontal louvers installed either on the internal or external side of the wall work better than vertical ones. An exterior louvered overhang above solar glazing allows more daylight into a space while also blocking unwanted summer sun. For cases where flexibility is sought, adjustable blinds and louvers can be employed provided they are actually used properly on a day-to-day basis, either manually or automatically. They also need to be cleaned and maintained to reflect and operate properly.
All of these add-on approaches to light and glare control assume that the fenestration is glazed with clear or tinted glass that is permanent (i.e., static) for the entire life of the building. However, glazing used in fenestration is changing. Traditional static windows can be replaced by new dynamic options that do a much better job of balancing daylight, glare control, and energy efficiency. Specifically, dynamic glazing is an available glass product that tints automatically in response to the sun and can be supplemented with manual control as needed. As a thoroughly 21st century product, the tinting of the glass is controlled by electronic sensors and intelligent controls that allow for variations in the level and pattern of tinting. As such, dynamic glazing enhances occupant comfort and well-being while maintaining a connection to the outdoors. Perhaps equally significant, it changes and controls the light levels without the need for any additional products such as blinds, shades, louvers, or light shelves.
Jordan Doria is the senior channel marketing manager at Saint-Gobain SageGlass, a manufacturer of dynamic glazing. He sees first-hand the impact of this technology and says, “Dynamic Glazing represents a paradigm shift in the fenestration industry. It transforms glazing from a static building component to an active one, something that can be controlled and used to contribute to building performance goals relating to comfort and energy efficiency.”
Photo courtesy of Saint-Gobain SageGlass
Electrochromic dynamic glazing can be automatically or manually tinted to achieve different levels of light and solar heat gain control in response to changing sun conditions.
Of course, it should be noted that there are different types of dynamic glazing on the market. Some are based on treating the glass to respond to light (photochromic) or heat (thermochromic), allowing them to change tint based on the level of either heat or light detected in the environment around the glass. Eyeglasses that respond to the difference between indoor and outdoor light levels and tint or clear accordingly are a common example of this technology. There is, however, another type that is more specifically designed for use in buildings. This type is called electrochromic because it uses a very small amount of direct-current electricity to create different levels of tinting. The amount of electricity used is minimal and replaced many times over by the potential energy savings from its proper operation.
Electrochromic dynamic glazing is made from panes of conventional float glass that are sputter coated with ceramic layers of metal oxides. The specific processes are proprietary to the manufacturers but are similar to the way low-e glass is produced. In most cases, nanotechnology is used to control layers to a very fine degree. The total thickness of all the layers of an electrochromic coating is commonly less than 1⁄50 of the thickness of a human hair. When a small electronic charge is applied across the coatings, ions travel between layers, where a reversible solid-state change takes place, causing the coating to tint and absorb light. Reversing the polarity of the applied voltage causes the ions to migrate back to their original layer, and the glass returns to its clear state.
The coated panes of glass are fabricated into insulating glass units (IGUs) using another piece of glass (clear, tinted, or laminated) and a stainless steel spacer. These IGUs can be fashioned into windows, skylights, and curtain walls, making advanced electrochromic dynamic glazing as easy to specify and install as any conventional static glazing. These glazing products are available in an array of shapes, sizes, colors, and configurations and can be installed in windows, skylights, and curtain walls.
The control mechanisms to affect the dynamic tinting changes are typically based on strategies using up to four different tinting levels: clear, light tint, intermediate tint, and dark tint. These different levels help with varying levels of daylight control, glare control, building occupancy schedule, and other building specific factors. An electronic control system can be used to receive automated commands from other devices, such as a daylight sensor, occupancy sensor, or sensors tied into a central building management system (BMS). Commands to tint or clear can also be given manually by using wall switches or similar devices. Either way, depending on the sky conditions (cloudy vs. clear) and sun position, the control system will receive the commands to control tint level to achieve the desired, optimized foot-candle level for the daylit space. With overcast skies, the glass may be cleared to admit enough daylight to achieve optimum illumination. Conversely, with clear skies, the control system can darken or partially tint the glazing to limit daylight to obtain the same foot-candle target, while concurrently reducing solar gain. By using multiple sensors in multiple locations, the tint level can be linked directly to the amount of daylight or solar gain desired in any particular building space or even different panes of glazing. Daylighting controls based on seasonal variation can block solar gain in summer to reduce air-conditioning loads or allow more solar gain in winter to reduce heating needs. In this way, dynamic glazing provides much greater energy savings than any static glazing product can deliver.
Advances in electrochromic dynamic glazing offer some additional choices as well. The tinting can be arranged in zones within a series of panes of glass so that different tinting levels can be achieved as needed; for example, darker on top and lighter below. It is also possible to specify such zoned tinting within a single pane of dynamic glazing. The latest version of this product also allows for a gradual transitioning between the zones instead of a distinct line. These advancements reflect the continued growth and development of this innovative glazing product. As Doria looks at the state of the industry and sums it up, “Dynamic Glazing has nearly 30 years of development history behind it and is now a mainstream building product. Though still a small part of the overall architectural glazing market, it has proven its feasibility across applications, and its growth will be supported by macro-trends in the construction industry, such as designing for well-being and ultra-energy-efficient buildings.”
Photos courtesy of Saint-Gobain SageGlass
Electrochromic dynamic glazing has advanced to allow for different tint levels to be incorporated into different panes of glass or even within the same pane of glass to achieve desired results.
Conclusion
Fenestration provides many real benefits to buildings but can also create some unintended issues. It is therefore very important to assess and understand the design impacts in the amount, type, and characteristics of the fenestration provided in a building. It is equally important to understand the performance capabilities of different fenestration product types in order to achieve the intended overall building performance. Architects who embrace the depth and breadth of available fenestration information and assistance can create truly noteworthy buildings of all types in virtually any location.
End Notes
1“Applying Wellness Principles to Residential Construction.” NeoCon. June 2018.
2Browning, Bill. “The Economics of Biophilia: Why designing with nature in mind makes financial sense.” Terrapin Bright Green. 2014. Web. 8 January 2019.
3Circadian Rhythms. National Institute of General Medical Sciences. Web. 8 January 2019.
4Alice, Walton. “Your Body’s Internal Clock and How It Affects Your Overall Health.” The Atlantic. 20 March 2012. Web. 8 January 2019.
5Ford, Bob. “Harnessing the Power of Natural Light.” Work Design Magazine. 24 May 2017. Web. 8 January 2019.
6Joshi, Sumedha. “The sick building syndrome.” Indiana Journal of Occupational & Environmental Medicine. August 2008. Web. 8 January 2019.
7Grabar, Henry. “Welcome to the permanent dusk: Sunlight in cities is an endangered species.” Salon. 20 April 2014. Web. 8 January 2019.
8“Applying Wellness Principles to Residential Construction.” NeoCon. June 2018.
Peter J. Arsenault, FAIA, NCARB, LEED AP, is a nationally known architect, consultant, con-tinuing education presenter, and prolific author advancing building performance through better design. www.pjaarch.com, www.linkedin.com/in/pjaarch
