When Macy’s Herald Square unveiled its renovated women’s shoe department, the World’s Largest Shoe Floor – a whopping 65,000 square feet spanning the immense building’s entire second floor – had everyone talking. The Condé Nast set crowed about its inventory of more than 300,000 pairs of shoes. England’s Daily Mail pit the Macy’s square footage against the similarly ample shoe floors at Saks Fifth Avenue and Selfridges – Macy’s won.

But size and scads of sky-high heels weren’t the only press-worthy elements of the Macy’s Herald Square shoe department overhaul. For the first time in years, the second-floor windows along the building’s Broadway side were uncovered, allowing natural light to filter into the space. “Opening up those windows,” says Steven Derwoed, vp of store design and merchandising at Macy’s Inc. (Cincinnati), “is like adding another amenity to the store – a vista out onto the city.”

For the design team at Macy’s, there are several advantages to bringing natural light into the store environment: It makes shoppers feel good; customers can see the true colors of the merchandise they’re buying; and, notes Derwoed, rather than creating unnecessary signage around the store, windows simply serve as landmarks to help shoppers orient themselves on the floor. “We’ve continued to evolve our thinking on natural light,” he says. “Even with mall-based Macy’s stores, we’re making entrances larger to let in more light or incorporating glass on either side of mall entryways to create better vistas into our stores.”

Further uptown, Bergdorf Goodman (New York) also exposed previously hidden windows at its building on Fifth Avenue and 57th Street, where its third-floor men’s European and American designer collections department reveals sweeping views of Central Park, the Grand Army Plaza and Fifth Avenue.

“Natural light is such a luxury in New York,” says Susan Homan, vp of visual presentation and store design at Bergdorf Goodman. “We knew we could not pass up this opportunity. It enhances the product and provides a breath of light for both our sales associates and customers.”

But incorporating natural light into the store environment isn’t as simple as just uncovering a window and letting a hefty dose of vitamin D pour in. Plus, sunny days aren’t guaranteed; natural light-filled spaces have to account for bad weather, shadows and the night sky.

“Our choices in materials and colorations had to be tested on location and at different times of the day,” Homan says. To cut down on the glare and shadows created from the windows, the Bergdorf Goodman team incorporated antique bronze metal-mesh floor-to-ceiling curtains. “We’re not only pleased with how well they function,” she says, “but they also provided a strong design element for the entire floor.”

Lighting designer Paul Gregory, founder and president of Focus Lighting Inc. (New York), compares using natural light to choosing the color of a wall. “It’s design work and you want to use what’s appropriate,” he says. “Sunlight and open views are great as long as they’re controlled and do not compete with the product.”

To control natural light in projects such as Frye Boots in SoHo and the Proenza Schouler boutique along New York’s Madison Avenue (the womenswear and accessories brand’s first-ever store), Gregory and his team suggested that the product maintain a healthy distance from the front windows. “If the daylight is far enough away,” he says, “then you love it and enjoy it, but it doesn’t adversely affect the product.”

On the other hand, Macy’s designers liken the windows to bright, eye-catching beacons, and choose to position merchandise directly in front of them. But Derwoed acknowledges that “any product we put in front of them will be viewed in silhouette,” so designers placed double-headed, 25-degree LED PAR lamps approximately three feet apart and about three feet off the face of the merchandise to overcome bright daylight.

Additionally, with a combination of LEDs and fluorescents, the store’s interior is lit three times brighter than the ambient light coming in through the windows. And that three-times-brighter solution doesn’t change even when the external light does.

Derwoed says the team is currently studying photo sensors, which are attached to the store’s lighting system, and automatically dim or brighten so the light is consistent despite weather or time of day. “We plan for the worst-case scenario,” he says. “No matter what, we want to provide the optimal amount of light so the product always looks fantastic.”