Demonstrating the value of an environmentally responsive sustainable-design installation is easy for some classes of occupancy. For example, in an office building, the value of a 1-percent increase in office productivity (about 4.8 min per day) can be valued at some $4 per sq ft per year, an amount that often exceeds the total cost of all heating/cooling/power for the same building. Further, several studies, both completed and under way, suggest that productivity increases in green-building spaces are significantly greater than 1 percent.

Several organizations are active in evaluating the relationship between environmental quality and productivity, with the work done by Steelcase Corp. in association with Carnegie-Mellon University cited most often.

For office environments, increased productivity easily justifies the growing interest in environmentally responsive design and any increased costs that may be incurred to achieve it. That type of cost-benefit analysis is more difficult to apply to the lodging industry. Certainly, getting more production out of staff is worthwhile, but the primary goal--increased value to guests--though real, is hard to quantify. That notwithstanding, the business guest who consistently gets a more restful night's sleep because of little noise, good air quality, and good thermal/humidity control; who is productive in the evening because the lighting has not tired him further by causing eye strain; and who appreciates that his stay is minimally invasive to the environment is more likely to come back, and that is the essence of a successful hotel. Hotels that have embraced the environmental solution report exactly that kind of repeat busines