Many opportunities to green medical facilities are similar toany large commercial building--solar panels, green roofs and use offluorescent bulbs and photovoltaics can be done anywhere. Buthospitals, research laboratories and dentist offices do posecertain special challenges, given their intense use of water forcooling, special ventilation needs, material concerns and 24/7operation.

"While some things are the same, a lot is different abouthospitals," says Alan Scott, a principal at Portland, OR-basedconsultancy Green Building Services. "For example, unlike an officebuilding--where water use predominantly is in the bathrooms--inhospitals it is used for cooling equipment. In fact, because of thenature of its occupancy, a lot of cooling systems are in use."

And though the trend toward more outside air also has reachedhospitals and clinics, air circulation is another issue wherehospitals differ somewhat. Medical facilities require morestringent types of filtration for treatment and surgical areas toprevent contamination. OHSU used natural ventilation and outsideair for cooling some areas of the building, but used specialfiltration that removes 90% of particles larger than one micron(vs. a standard 70% removal of particles larger than 3 microns) inmedical treatment and outpatient surgery areas.