Best Practice Guide

Commercial Office Buildings

Introduction

Planning an Energy Program

Funding and Approval

Lighting

Offices and Workstations

Daylighting

Hallways and Corridors

Restrooms and Closets

Signage

Outdoor Areas

Building Envelope

Central HVAC System

Distributed Generation

Demand Response

Commissioning

Procurement Policy

Water Use

Education

Energy Efficiency in Telecommuting

Resources and Appendices

Lessons Learned


Adobe Systems Incorporated and Cushman & Wakefield

Arden Realty and next>edge

Cypress Semiconductor

Equity Office Properties

Glenborough Realty Trust

Natural Resources Defense Council

Qualcomm

Swinerton, Inc.

Transwestern Commercial Services


View the Glossary

Lighting

Daylighting

Printer-friendly version

Share your thoughts

Light well at NRDC, Santa Monica. Photo by Tim Street-Porter, courtesy of NRDC.View Details.

Many people are familiar with the business maxim, "Cheaper, faster, better - pick any two of the three." Unlike most things in life, though, daylighting achieves all three.

Daylighting is cheaper. The only investment needed is for design and installation of equipment related to the fenestration, e.g., a skylight, a light tube, or a clerestory. In general, horizontal installations like skylights, light tubes, clerestories and light wells are easier to install and more cost-effective than their vertical counterparts (windows). Adding photosensor controls allows you to maximize energy savings by automatically shutting off or dimming superfluous fixtures according to changes in the level of natural light. This combination of technologies maintains a consistent light level throughout the day and the seasons, and reduces peak operating costs.

Daylighting is better. Daylight literally outshines any artificial lamp on the market - it is brighter, more appealing, renders color more accurately, and is much better for visual acuity. This is important for visually oriented operations. Daylighting provides high-quality light without relying on expensive artificial fixtures.

Daylit Conference Room. Photo courtesy of Swinerton, Inc.View Details.

And, while daylighting may not be "faster," tenants often find that they get more accomplished in a shorter period of time while working under natural lighting conditions. Daylighting reduces eyestrain and is known to have subtle effects on productivity and comfort. Studies have shown that daylighting in schools improves student math and memory skills and increases sales in major retail centers. Anecdotal evidence supports these findings, suggesting that workers increase productivity and reduce absenteeism when provided with natural light. Daylit spaces tend to be designed with large expanses of windows that provide a view of the outdoors, another factor found to contribute to occupant comfort and worker productivity.

Business Examples

Swinerton, Incorporated, uses daylighting extensively throughout its corporate headquarters building. More than 90 percent of the workstations receive direct or indirect sunlight and 75 percent of the building's occupants are afforded views to the outside. Swinerton has found that these changes helped boost worker productivity in the building, which in turn helped quicken the payback timeframe.

At the Southern California headquarters for the Natural Resources Defense Council (NRDC), architects made use of daylighting in designs for this renovated 1917 building. The office building takes advantage of the ample natural light through windows, light wells, interior clerestories, and architectural glass. These openings provide staff with outside views and access to outdoor terraces. High efficiency T8 and T5 fluorescent fixtures with electronic dimmable ballasts supplement the daylighting and are controlled by both occupancy and photosensors to minimize use.


Resources

Lawrence Berkeley National Laboratory, Windows and Daylighting: Daylighting.

Pacific Gas & Electric, Daylighting Initiative.

Architectural Energy Corporation. Sensor Placement + Optimization Tool (SPOT) is available for free online. SPOT assists designers with proper placement of photosensor controls.