Apartment and condo dwellers in New York City pay extra for great views, with rents typically rising just as quickly as the elevator. But a study by the Urban Green Council in New York reveals that most of this high-price glass is usually covered up.

Night and day, residential or commercial building, and regardless of the window’s orientation, well over half the total window area is obscured.

“While the environmental downside of all-glass buildings is well documented in the green building community, we set out to answer a different question: what is the behavior of tenants in NYC who live and work in the all-glass residences and offices with those breathtaking views?” says the council’s report. “We looked at dozens of all-glass buildings and found that on average, blinds or shades covered about 59% of the window area. Tenants are moving into these rooms with a view, but more often than not, can’t see out the windows.”

Patterns did not follow assumptions

Researchers photographed 55 buildings in Manhattan, Brooklyn, and Queens over a three-month period in 2012. The properties included 18 commercial and 37 residential buildings. With more than 100 photos in hand, researchers then measured the fraction of each window covered by blinds or shades.

Here are some of their findings:

• More than three-quarters of the buildings had more than half of their window area covered by blinds or shades.
• Tenants don’t seem to use blinds and shades to block strong morning and afternoon sun. That is, in the morning, slightly more window area on the western side of the buildings was covered, and in the afternoon, slightly more east-facing windows were covered — exactly the opposite of what might be expected.
• Patterns seemed roughly the same no matter which direction the windows faced, and there was “no appreciable difference” between commercial and residential buildings.
• The use of blinds and shades didn’t seem to increase at night.

“This suggests glare may not be the reason blinds are widely in use,” the council says. “Perhaps it’s privacy, the inconvenience of raising them once they are lowered, or some other cause.”

Environmental price tag is very high

If the only downside was the amount of money tenants waste by not taking advantage of the views they pay for, there might not be much to squawk about. It is, after all, their money.

But walls of glass are extremely poor thermal insulators, leading to a variety of ill effects on society as a whole, the Urban Green Council says. Among them: higher energy costs, increased power requirements, more carbon pollution that contributes to global climate change, and more air pollution. Because windows last 50 years or more, those problems are extremely long lasting.

“Tenants also experience drawbacks from large windows,” the report concludes, “including less privacy, more noise, and an increased risk of dangerous indoor temperatures during a blackout.”

The Council made two suggestions. First, professional who design buildings should collaborate on ways to maintain great views while solving energy and comfort issues. Using fiberglass frames, for example, rather than more conductive aluminum would save energy. Insulating the lower two or three feet of outside walls would still provide plenty of natural light but also cut down on energy losses.

Second, the council said brokers should make sure that tenants understand the “full implications” of living in a building with lots of glass. “That way,” the council says, “prospective tenants can make decisions with a clear understanding of what’s in store before they move in.”