Farewell to the Traditional Balcony?

Recent improvements in glass manufacturing and smart-home technology have dramatically improved soundproofing; waterproofing; and anti-reflection, anti-glare, mechanical and privacy issues. This has made the transparent material more appealing for residential use, giving architects more freedom to design condominium and rental apartment high-rises with sleek, clean lines.

And by tossing out balconies, architects avoid other design and safety concerns. One is "the possible strong wind load that may increase with the height of the building. This may create a strong uplift, causing furniture on the terrace to get blown away," said architect Toshiko Mori, chair of the architecture department at the Harvard University Graduate School of Design.

The all-glass structure emerged as a 21st-century residential design trend when Meier introduced the idea in his jewel-like multi-unit condominium building along the Hudson River in Manhattan's West Village. Its towers were built with open-air balconies cleverly veiled by green-tinted glass panels placed strategically along the facades to create the impression of seamless construction. The balconies blend into the side of each building, giving the property a clean, fresh look.

"Adding balconies was a way to add more sex appeal to the building," said James Lansill, senior managing director of the Corcoran Sunshine Marketing Group in New York, which markets real estate developments nationwide. His firm marketed the Meier buildings, and he is a resident in the property.

"Now with the floor-to-ceiling glass, you get such spectacular access to light and views, and it does diminish the value of the balcony," Lansill said.

Designers and sellers say the market typically dictates whether a balcony gets included in the package.

"It's absolutely a fact that outdoor space provides a premium value to an interior space," Lansill said. "The trade-off with a balcony is that it often cantilevers out to give you access to the outdoors, but it blocks light for the unit below and may obstruct your own view."

Two Manhattan condominium properties designed by French architect Jean Nouvel and marketed by Corcoran are among several planned as shining glass structures without balconies, Lansill said.

The 14-story 40 Mercer in SoHo sold out at $2,300 a square foot. The 23-story 100 Eleventh Avenue in Chelsea, which recently went on the market, sold nearly half of its 72 units for $2,300 a square foot in the first two weeks. "Both offer very innovative glass walls, and buyers are just flocking to them," Lansill said.

But most in the real estate business say it's too early to write off the balcony as either a lackluster design element or a weak selling point.

Across the Hudson in Edgewater, N.J., the architects of One Hudson Park, a 15-story condominium project with 168 units due to open in July, combine the contemporary feel of a glass-and-brick structure with balconies that are tucked into the building's corners. The building has spectacular views from its perch perpendicular to the Hudson River.

Balconies clearly have their fans.

"They are very cozy. You can sit there, get out of the wind and still have a wonderful view," architect Peter Samton said. He's a partner in the New York firm Gruzen Samton, which specializes in residential buildings, a little more than half of which are designed with balconies. One Hudson Park is one of its buildings.

"Balconies are very important to our business and tend to fetch a higher price -- about 5 percent above the asking price," said William Rosato, senior vice president of Tarragon Development, which developed the One Hudson Park property, now about 75 percent sold at $700 a square foot. "If there's a choice between a unit with a balcony and one without, a buyer will go for the balcony."

But he recognizes that in some condo developments, the design often makes more sense without balconies, as in his firm's 10-story high-rise condo project, Trio, currently under construction in Palisades Park, N.J.

"It's just the way project design evolves."