The trend toward outdoor living, which uses comfy seating, bright rugs and weatherproof art to extend the al fresco season at home, is bringing new attention to a centuries-old architectural feature: the courtyard.

"It's the original outdoor room," said Philip Weddle, principal architect of Weddle Gilmore Black Rock Studio in Scottsdale, Arizona. "Courtyards are as much about enriching the indoor spaces as creating amazing outdoor spaces. That blurring of the boundary between indoors and out makes the experience of each space richer."

Courtyards — a staple in Roman, Middle Eastern and ancient Chinese architecture — are becoming popular in homes throughout the United States, builders and architects say.

As they have for thousands of years, courtyards offer a safe and private area for families and guests to gather. In urban areas, especially, such secluded outdoor space is rare. Courtyards increase the amount of living space in a home. And when designed right, they can create a cooling retreat in warm climates.

Improvements in retractable glass walls and sliding doors have helped make them more feasible.

"That technology has really improved over the last decade," Weddle said. "It really does allow you to open interior space to a courtyard more easily."

People are accessing that outdoor space to cook, dine, entertain or just relax, Weddle said. He's designed small courtyards that connect to a master bath and include an outdoor shower. "Courtyards come in all shapes and sizes," he said.

Builder Nilay Bhatt, president of Dani Homes in Columbus, Ohio, also sees more Midwestern customers choosing courtyards: "It's an element of outdoor living," he said.

And in older suburban neighborhoods in Atlanta, Ed Castro Landscape has helped clients add courtyards to existing homes, said Hannah Seaton, a senior landscape design consultant with the firm. "They're trying to turn an area of their property into a private place," she said.

Luckily, the footprints of many older homes include nooks and hidden spots that lend themselves to courtyards, Seaton said.

In other places, homeowners are creating courtyards in front of houses by adding plantings and paving stones. That can increase curb appeal, reduce the amount of water-guzzling lawn, and showcase a water feature or piece of sculpture, said Tanya Wilson of Bonick Landscaping in Irving, Texas.

Front-yard courtyards can be casual (benches and gravel walkways) or formal (statues, fancy lighting and fountains). The key, Wilson said, is selecting a look that matches the house's architecture.

"It's a nice transition from the street to the front door," she said. "It can feel more welcoming."

But the appeal of a courtyard doesn't stop at the door, said Missy Henriksen, vice president of public affairs for the National Association of Landscape Professionals in Herndon, Virginia. The courtyard's purpose is to connect the home's interior with the outdoors, she said.

"Most landscape features bring the indoors out. With the popularity of outdoor living, we think of landscapes as extensions of our homes," she said. "Courtyards are unique in that they flip this idea by instead bringing the outdoors inside the home, allowing the beauty of the courtyard to be seen from several areas of the home."

Courtyards are all about the sight lines from inside the home, agreed Tracy Schiefferle , interim director of the Building Industry Association of Central Ohio. Several builders in recent years have included front courtyards in homes for the association's annual Parade of Homes, which showcases trends. "We're definitely seeing more attention to the front of the house," she said.

Front courtyards make sense in neighborhoods trying to build community, she said. They mix well with walking trails, bike paths and other amenities designed to help homeowners stay active, Schiefferle said: "It reflects how people want to be connected to their neighborhood."