Consequently, daylighting is no longer considered a ‘viable’ energy-saving design strategy for some because it does not pencil out from a simple payback or ROI point of view. Since many design professionals have bought into this way of thinking and have become hostage to it, they have lost the ability to forcefully argue against this narrow energy economic view of daylighting.
If architects care about improved occupant comfort, health, and productivity, and about achieving significant energy savings, then aggressive daylighting is an essential design strategy. However, it must be an integral part of all their designs, just like indoor plumbing, and not subject to the vagaries of ROI calculations and simplistic energy economics. Architects make thousands of decisions and trade‐offs during the course of designing a building; ensuring the inclusion of aggressive daylighting into their designs is easily accomplished when it is a high priority, particularly if an integrated design process (IDP) approach is used.
Current marketplace economics do not properly value all the benefits of daylighting—rather, it demands meeting narrowly defined energy economic criteria before being considered and incorporated into buildings. Daylighting must become a mandatory requirement in building codes and standards, such as American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) 189.1, Standard for the Design of High-Performance Green Buildings, and the International Green Construction Code (IgCC).
The requirements must address both quantitative (illumination levels) and qualitative (glare) issues in the daylit zones, and do so in a performance‐based approach. Currently, most daylighting code requirements, such as California’s Title 24, address only electric lighting controls (i.e. require daylight harvesting controls ) in the perimeter zones of buildings, and do not deal with occupant visual comfort like glare or high contrast ratios.
Architects must become better educated in understanding and applying daylighting design principles. In an ideal world, more design professionals would be forceful and effective in advocating for daylighting with their clients. Simply put, they should not condone or participate in the misdirected conversations regarding daylighting economics, unless all the energy and non‐energy benefits of daylighting are allowed to be included in this economic analysis.
Michael J. Holtz, FAIA, NCARB, FASES, LEED AP, is an architect and a co-founder of LightLouver LLC, located in Louisville, Colorado. Previously, he was president and CEO of Architectural Energy Corporation, chief of the building systems research branch of the Solar Energy Research Institute (now known as National Renewable Energy Laboratory [NREL]), and a research scientist at the National Bureau of Standards (now National Institute for Standards and Technology [NIST]). Holtz is currently leading an effort to develop a daylighting code for ASHRAE 189.1. He can be reached via e-mail at email@example.com.
4 comments on “Are we thinking about daylighting all wrong?”
Daylightng has never “paid off” only by turning off lights because we pay so little for precious energy resources in the
US. A more sophisticated analysis would take into account the reduced maintenance cost for lighting fixtures that are
used less than full time, and the better return on investment for fixtures that last longer. While not my area of expertise,
there must be payback in reducing heating and cooling loads, depending on climate. For instance, there might be
less cooling load with light fixtures turned off, and less heating load with the help of solar radiation.
The less tangible benefits were investigated in studies initiated by the California Energy Commission, with some
quantifiable results. Links to the reports can be found here:
There are probably other studies as well.
Daylighting is one of the several ways forward. Futura has a modified Sawtooth roofing system that combines Solar Thermal (air & water) into sawtooth roofing that makes several solar benefits routinely available to the business beneath the roof. No need to go “off grid” when backing off the peak power spike will serve so well.
This is an interesting angle of consideration. This article sheds light on the true intentions of LEED goals.
The additional of a curb mounted skylight, atrium, etc benefits occupants in multiple ways…day lighting, comfort, work environment, etc.
However, as time has progressed it seems the focus has been overshadowed by the benefits of saving electrical expenses. Thus the day lighting movement has evolved into a topic of lumens and electricity.
The main idea to begin with has been set to the side and has become overlooked.
LEED intentions/ goals were to capture gains in all disciplines with focus on its impact to not only energy efficiency but also how these things would have a positive impact on inhabitants.
As with many things it is our nature to get sidetracked and to forget about asking the question on each and every project…What benefits would day lighting provide this facility? Is there a benefit to the tenant? What is the payback? What is the term of payback? How does this affect others and neighbors? Is this sustainable and is it safe?
Day lighting through roofs should always consider the safety aspect. What do you think occupants would feel like if the skylight appearance is ruined by a fall protection system?
Article definitely brings up a good point of consideration.
Conversations about daylighting economics are misdirected unless the non‐energy benefits of daylighting are allowed to be included in the economic analysis of a proposed building. Very good point in a well written article. The largest single cost of operating a building over its life is not the cost of energy, maintenance or mortage. It is the cost of the human capital that will occupy the building. This includes wages, benefits, education imparted, the health of occupants and their capacity to perform the vital tasks of the organization.
While energy reduction is a key component to the future of our built environment, the quality and benefits of well designed daylighting cannot be lost in the process.