New Zealand–born Sandra Nunnerley studied art history in London and Paris and worked at New York’s Marlborough Gallery before setting up her design practice in 1986. Her career is marked by a keen ability to incorporate serious art into comfortable and luxurious rooms. A New York playroom is no exception. Here, Ray Parker’s Untitled, 1980, plays off a whimsical red chair and ottoman by Malian designer Cheick Diallo. Photo by Pieter Estersohn

Although none of the California projects designed by Frances Merrill, of L.A.’s Reath Design, look alike, all demonstrate her acuity in mixing color and pattern, which, she says, gives a room layers and the sense that “it’s slowly been created over time.” When it comes to kids’ rooms, Merrill maintains that this approach has the added benefit of making a mess disappear. “If you have this very spare space, you’re going to see everything that’s out of place.” Here, a top-to-bottom coat of Benjamin Moore’s Caldwell Green and prints of baby animals by Sharon Montrose help bring nature inside. Photo by Laure Joliet

Architect Kevin Lindores and interior designer Daniel Sachs first met while working for Frank Gehry. The pair, partners in life as well as work, launched Sachs Lindores in 2000 and frequently attract creative types with their sensitive, stylistically varied projects. The loft of Dutch-born photographers Inez Van Lamsweerde and Vinoodh Matadin, located on the Bowery of Manhattan, resembles a Japanese tea house crossed with a Swedish sauna. In this wood-wrapped, kid-friendly space, an inviting nap nook is upholstered in Colefax and Fowler fabric while petite vintage French and American chairs sit atop a Moroccan rug. Photo by Inez and Vinoodh

When renovating their Beverly Hills home, fashion designer Jenni Kayne and her husband, Richard Ehrlich, turned to Standard, the architecture firm behind Kayne’s West Hollywood and Brentwood boutiques. Surrounded as she is by color and pattern all day, Kayne wanted her domestic interior to have a soothing, neutral palette, right down to the playroom of her two children, Tanner and Ripley. In this light-drenched space, wooden toys, a custom-made teepee and vintage odds and ends fuel the fun while maintaining a serene sensibility. Photo by Lisa Romerein/OTTO

For many, especially city dwellers, being able to devote a whole room to child’s play is a fantasy on a par with laundry rooms and walk-in closets. Turns out, even rock stars face space constraints. Here, in the New York pied-à-terre of Coldplay guitarist Jonny Buckland and his family, Ariel Ashe and Reinaldo Leandro, of Ashe + Leandro, converted the hallway outside the children’s rooms into a cozy playroom enclosed by glass French doors. Built-in cubbies store toys, walls covered in chalkboard paint invite creativity, and a mini Saarinen Womb chair offers a stylishly small seat. Photo by Alex Cholas-Wood

“This project was for a Southerner who moved to L.A.,” says Barrie Benson, who worked in such far-flung places as Greece and Germany before settling in Charlotte, North Carolina. There, she combines her Southern roots with her international experiences to bring modernity into traditional spaces, and vice versa. For this young girl’s room, she painted the walls a pale purple, incorporated feminine touches like a delicate lamp from Remains Lighting and added monogramming to maintain, as she puts it, “Southern priorities.” Of the fresh yet classic space, she says, “I wanted it to feel preppy-meets-flower-child.” Photo by Laura Resen

When gut renovating their Greek Revival townhouse in Brooklyn’s Boerum Hill, architect Bastien Halard and landscape designer (and Vogue contributing editor) Miranda Brooks opted to have each floor represent a nationality: the first French (his), the second English (hers) and the top one American (theirs). The bedroom of their daughter Poppy is on the second floor and bedecked in wallpaper from London’s Marthe Armitage handprinted with birds, butterflies and spiderwebs. Her sister, Violette Grey, got horse chestnuts. Brooks picked up the rug in Morocco. Photo by François Halard

Ellie Cullman and her team at Cullman & Kravis are known for their ability to maintain the sense of tradition revered by their Upper East Side clientele while making things modern with sleek contemporary accents, edgy art and pops of color. Cullman originally worked on this Park Avenue apartment 15 years ago and was recently summoned to give it an update, which included transforming a once pink and green chinoiserie-heavy girl’s room into a space befitting its now-teenage occupant (a competitive show jumper, as seen in the wall photos). The daybed turns into a trundle for sleepovers, the ceramic lamps are by Jonathan Adler, and the turquoise mirror is from Hiden Galleries, in Stamford, Connecticut. Photo by Nick Johnson