As sustainable issues such as energy efficiency and quality environments permeate the design process, one particular topic—daylighting—is at the fore of many a “green” discussion. With daylighting strategies being implemented in so many of today's buildings, the question is: Are we ready to require buildings in the United States to be daylit? And if so, what are the implications? Replies can be submitted to email@example.com.
DENISE FONG | PRINCIPAL | CANDELA
This is an interesting question and could be answered on many different levels. There's the architectural level, which would require the proportions of buildings to change; floor plates generally would need to be narrower than we typically build today, and ceilings would need to be higher. We would need daylight glazing in addition to view glazing. Exterior shading devices would need to be the norm rather than the exception. Orienting a building to optimize it for daylight is a challenge for many sites and may not even be possible in many dense urban cities. It would require changes to zoning regulations, requiring more slender towers with more space between them. There is considerable cost to these elements from a developer's point of view.
Effective daylighting also requires higher quality, more sophisticated controls to allow the electric lighting to work effectively in concert with the daylight. Code requirements for automatic daylight controls will create the market demand necessary for high quality affordable control products.
In Europe, to be considered a Class A building it must be daylit and have natural ventilation. These two criteria drive the design of the building envelope. The precedent is there. The question is can we accept the challenge? Like many sustainable strategies, seeing examples of others who have done it successfully gives encouragement to the masses. I would like to see broadly available incentives rather than requirements for building envelopes to provide better daylighting. Controls could be developed more rapidly with code requirements.
JEFFREY T. BERG AND JOHN L. POWELL | PRINCIPALS | PB
Requiring buildings to be daylit would improve our luminous environments and, if properly detailed, save energy. The basic tools to evaluate daylighting in buildings have been available for decades. We would have to design carefully to avoid glare and overheating. It would be critical to coordinate zoning requirements, allow adequate views of the sky, and control massing, setbacks, and floor depths with respect to the exterior wall to maximize utilization. For example, some European codes require that every worker have direct access to daylight. This virtually eliminates both the continuous band of perimeter private offices and the massive floor plates of corporate headquarters.
NEALL DIGERT | VICE PRESIDENT OF COMMERCIAL DEVELOPMENT | SOLATUBE INTERNATIONAL
Unequivocally, YES. Aggressive use of daylight in buildings has been required by other industrialized countries for decades. Recent scientific research has found that access to daylight is key to how humans function, both physically and psychologically, and as such, we now know that we (the design community) are doing a disservice to our population if we don't aggressively apply daylight as a building standard. The use of daylight for interior illumination leads to decreased absenteeism, increased productivity, improved student test scores, increased retail sales, increased property values, reduced environmental pollution…the list goes on.
As visual beings, daylight is the perfect illuminant, but issues stemming from old daylighting design techniques have prevented daylighting from being easily and successfully applied in U.S. buildings—until now. Daylighting technologies now provide substantially greater daylight collection and better delivery systems, as well as sophisticated electric lighting control technologies, making daylight as easy to apply as electric lighting in most instances, and sometimes even easier.