Natural Light in Commercial, Industrial, or Agricultural Buildings

Daylighting offers many benefits to people and animals.  Whether it be skylights for metal roofs or natural light for a hen house, these additions can not only save money, but improve productivity and yield.  Polycarbonate panels offer the best daylighting solutions, whether it be eave lighting, skylights, or another installation method.  For adding natural lighting, polycarbonate sheets will outperform a Plexiglass roof and a Fiberglass roof in a variety of key measures.

Why add natural light?

Adding natural light to a location is an environmentally friendly option to reduce electrical costs while still providing all the benefits that come from harnessing the value of light.  Most of how our world functions revolves around cycles of light.  For centuries our working hours revolved around daylight.  Modern technology has changed our understanding and use of light over the last 100 years or so, but this relatively recent change has not altered how our world still revolves around cycles of light.  This is true for us in our lives and business, as well as for plants and for other animals too.


Within the continental US and into southern Canada, natural light is a resource that is plentiful in both summer and winter.  With as much as 10 hours of natural light in the winter and 17 hours in the summer, skylights and other daylighting solutions can provide much of your lighting needs on a typical day without electricity. Modern electrical sensors now exist that can measure light intensity and wavelengths to supplement natural light and optimize lighting conditions specific to a variety of environments.

natural light

What are the Benefits of Commercial Daylighting?

In industrial, office, and warehouse settings, natural light has been shown to improve wellbeing and promote productivity.  Daylight is the best source for vitamin D, synthesizing naturally in our bodies.  But during the winter where all the daylight hours dwindle, an employee could miss all the sun simply by working their typical 9 to 5 shift.  Natural light improves employee mood and morale, it can help with focus, and it has health benefits to the employee as well.

 Neuroscientists have shown that well incorporated natural lighting helped to improve learning & retention by 16% in class and meeting rooms.  Workers with offices with natural lighting were 15% more creative.  Quality daylight exposure also resulted in a 6.5% reduction in sick time.  The Department of Design & Environmental Analysis at Cornell University calculated that being near a window with natural light improved productivity by on average $100,000 per 100 workers each year. In the 10-year lifespan of a polycarbonate window or skylight, this would be $1m of added productivity or $10,000 per employee.

warehouse lighting

What are the Benefits of Agricultural Daylighting?

In agricultural and horticultural settings, the cycles of light are closely related to production yields and animal and plant wellness.  Natural light can be used in lieu of or to supplement artificial lighting to reduce costs as well as naturally contribute to the environmental temperature.

Dairy Lighting

Light in Chicken Coops

Before accounting for the heating of hen houses, daylighting your chicken coop could save up to 75% of your energy costs each year.  Much like in dairy production, light cycles help improve egg production yields.  Hens typically lay eggs during the springtime when there is usually the most sun.  Keeping your hens in lit environments for longer portions of the year increases the length of time in which they are productively laying eggs.

Natural light in your chicken house can eliminate the need for artificial light when the sun is in the sky for long hours and reduce the need for artificial light when the hours of sun are minimal.  In Canada, where energy costs are typically about 70% higher than the USA, these savings can be even more significant depending on the size of your structure.  Natural daylighting can also improve heating costs in colder climates and increase the lifespan of your lighting and heating electronics by minimizing their use when natural light is available.

Light in Chicken Coops

Light in Dairy Production

Proper lighting in barns can increase milk production from 6% to 10% .  The ideal light levels are similar to those in your bedroom or in a commercial warehouse for a period of 16 hours, followed by 8 hours of low/overnight light.  Within much of the Continental United States and Southern Canada natural light can account for 60% to 70% of the lighting need during a sunny winter and up to 100% of the need in summer.

Indirect lighting such as ridge and sidewall lighting (explained below) are best suited for this application because of the need for low intensity light.  It is important to consider the path of the sun and the side of the structure your lighting is on.  This can also be achieved with higher opacity skylights that have lower levels of light transmission.  Commercial lighting with sensors can be used to optimize the proper level of light during winter months and keep energy expenses down.

Artificial Lighting

The use of artificial lighting is a great way to supplement natural lighting in any environment.  Where lighting quality is important as well as hours or duration of light, it is important to consider the use of sensors to evaluate both the natural light and the quality of the artificial light.  Though LEDs have given operators the ability to manage color to a greater extent, decreased light output (Lumen Degradation) is still evident in LEDs at a fraction of their stated lifetime.  Since this occurs lumen degradation in LEDs occurs slowly, it might not be noticeable that at less than half its stated lifetime, the amount of light has decreased by nearly 25%.

The Best Material for Skylights

When considering metal or other post-frame buildings Polycarbonate panels provide the best option for both installers and building owners.  Clear polycarbonate a more modern product that combines the benefits of many of the materials that came before it.


  • Glass windows were first used by the Romans in 100 CE, becoming popular in the western world in the 1600’s with the first manufactured window glass being made in Britain.  Modern window glass making techniques come from manufacturing advancements from 1900 to 1960.
  • Acrylic panels or sometimes generically known as Plexiglass was developed in the late 1920’s as an alternative to glass.  Slightly stronger and more resistant to shattering.  They are also easier to form and shape.
  • Fiber Reinforced Plastic (FRP) or sometimes generically known as Fiberglass is made of polymers reinforced with glass fibers for added strength.  After prolonged UV exposure these fibers degrade and become exposed, and the panel loses its integrity; both in strength and in color and opacity.
  • Polycarbonate panels are extruded thermoplastic sheets made from a synthetic resin.  Clear panels were developed in the 1970’s.  As such, clear Polycarbonate sheets improve upon or combines the advantages of the technologies that came before, such as glass, acrylic and FRP.  Polycarbonate sheets can be designed with a variety of light diffusing properties, while both blocking harmful UV radiation and allowing the safe and valuable visible light spectrum in.  Polycarbonate panels are easy to shape and incredibly durable.  Solid polycarbonate forms are now the material of choice for the creation of “bulletproof glass” because of their clarity and durable nature.


How does Polycarbonate compare to other materials?

From the perspective of building owners, polycarbonate retains it color and clarity as opposed to FRP and is stronger than both FRP and Acrylic panels.  Unlike common glass and acrylics, polycarbonate blocks nearly 100% of UV light.  This UV filtering improves the health and safety of every person or animal inside the structure.



Other Sheets & Panels


Polycarbonate blocks nearly 100% of harmful UV wavelengths, filtering out harmful rays that can negatively impact the health and safety of people, animals, and products.

Common types of glass and acrylic do not filter out nearly 100% of the UV spectrum.

Color & Clarity

Polycarbonate panels retain their color and clarity.

FRP is not as clear as polycarbonate and as it ages fiber bloom causes uneven discoloration and weakens the panels.

Impact Strength

Corrugated Polycarbonate sheets are up to 20 times stronger than acrylic and fiber reinforced plastic.

Glass and Acrylics are more likely to crack during impact such as hail.

Fire & Heat Resistance

Polycarbonate Panels are fire resistant throughout the panel.  Polycarbonate can withstand temperatures up to 270F for several hours and sudden burst of heat over 1100F without distortion or breakage.

Acrylic panels are flammable if cracked or damaged.  Typical window glass will fail as it approaches 250F.


For building contractors, polycarbonate panels are extruded to align with building profiles so they can be installed in-line with the existing construction process.  No need to frame out special sections or create special seals to ensure watertightness.  Polycarbonate can be drilled without cracking (and should be predrilled before installation) unlike acrylic.

The high strength of polycarbonate and the better UV performance means a longer lifespan.  This gives installers the confidence to warranty their work.

Other Options

There are other corrugated profiles and flat multiwall sheets can be used on sloped roofs especially when aligning with a common metal profile is not an option.  These installation techniques vary based on product and roof construction, but with polycarbonates ability to be bent and formed with ease, there can be many options for installation.

Gable, Sidewall, or Eave Daylighting

Sidewall or gable lighting is the placement of vertical polycarbonate panels on the wall of the structure, typically immediately below the eave or gable/rake on the sidewall or gable end respectively.  The difference is simply the shape of the roof.  Below the eave typically denotes the part of the roof below a slope, where an overhand exists.  The gable or rake edge is where we see the pitch of the roof come to a point.  It typically will provide a larger surface for daylighting installation.

Daylighting from the wall of a structure is an easy way to add secure natural lighting to an environment.  For such applications, the position and movement of the sun in the sky is essential.  Unlike traditional skylights, it is possible light can be obstructed, thus impacting product type and installation placement decisions before construction or retrofit.

Polycarbonate installed vertically tends to last longer because of the deflection angle (or trajectory) of ultraviolet light as it interacts with the surface of the panel.  The rake or eave also offers the panel some protection from the elements, making it less prone to water intrusion and impact damage.

This type of installation is a great option for all types of buildings, but specifically may be the best option for non-roll formed metal buildings or when matching the metal profile is not an option.  The profile of the polycarbonate is less of a concern in wall daylighting as closure strips can safely align panels with the other materials on the sidewall.  The gable or rake also offers added protection to the closure strips, improving their longevity.

roofing diagram draft


Methods of Daylighting Traditional Skylight Panels

Depending on orientation, traditional skylight placement creates the most opportunity for natural light to enter the structure in most cases.  Building location, orientation, and roof pitch will determine the amount of light the inside of your structure receives.  In very bright locations, where sunlight is direct, special diffusion or color panels can be used to reduce light intensity.

Though Polycarbonate panels can be used on all types of pitched roofs, corrugated polycarbonate has some specific advantages when used as part of roll-formed metal buildings.  Polycarbonate sheets are extruded to match the most common roll-formed profiles and thus integrate seamlessly into the construction.  With a variety of trade names, the most common panels are 9-inch on center and 12-inch on center (Ag Panel and PBR panel) respectively.  Corrugated polycarbonate panels are designed to align seamlessly with these common building panels, including the many minor variations in 9-inch on center products.

When metal prices rise, polycarbonate panels offer a potential financial relief.  At prices lower than metal, installers can keep their bids more competitive, while simultaneously improves the conditions within the building or structure.

Daylighting & Traditional Skylight Panels


Panels can be installed by replacing a row of metal roofing (ridge to eave), by replacing panels on a horizontal run, by periodically spacing panels across the structure (typically at the mid-span or a checkboard pattern), or another method that matches your desired aesthetic.  Always install on the lowest part of the roof pitch and move upward to ensure water and debris roll naturally from the top of the roof down the pitch.  Corrugated polycarbonate performs best on roofs with pitches of 2:12 or steeper.  Silicone or butyl tape should be used as a sealant when necessary.  This will improve watertightness, especially against windblown rain.


Polycarbonate panels are installed using the same tools and accessories being used for the metal components of your building.  Localized adjustments to the material can be made with simple hand tools, to cut the product to size where needed.  It is important to pre-drill all screw holes before installing screws.

Parts of a roof

Ridge Daylighting

Adding a daylighting ridge is likely the easiest form of retrofit for buildings without decking or a drop ceiling below the roof or when matching the metal profile is not an option.  Polycarbonate ridges can replace existing ridges to provide natural light into the structure.  This can be done as part of primary construction or many types of retrofitting projects.


Ridge lighting is likely to provide the least amount of natural light, especially in larger structures with where the roof plane is large in ratio to the amount of ridge space in the structure.  Roof pitch and the path of the sun in the sky will significantly impact the amount of sunlight that your structure receives.  For these reasons, ridge lighting solutions are best for smaller structures or two supplement other daylighting solutions.

Ridge light solutions are also good for buildings where only a little added light is desired or structures in climates where insulation along the roof plane is more important than daylighting.  This could be very cold climates or very warm climates, though polycarbonate has solutions to accommodate these climates as well.

  • For cold climates, consider multiwall polycarbonate which has better insulative qualities while still allowing for both natural light and the added value of heat the light brings.
  • For warm or high sun climates, consider opaque solutions with diffusion.  Opacity reduces the light transmission, while diffusion properties scatter the light.  This indirect light reduces the intensity of the sunlight at any one point.

Ridge Daylighting


Panels should be installed moving up the wall of the structure, so if multiple materials or panels are used the highest panels are the last to be installed.  Depending on preference and design, panels can be in-line with the wall panels, recessed or semi-in-line with the wall, or over the wall section.

The need for closure strips is dependent on the type of installation and the profile of the polycarbonate that is used. It is important that closure strips are not exposed directly to the elements from above, so panels should be nestled under the eave, rake, or fascia to protect the panel and structure from water intrusion.  Closure strips and/or other techniques to seal the panel should be used at the bottom of the panel, as seen in the picture above.

close up of shed