Designer Summer Thornton conceives a stunning retreat in Sayulita, Mexico, with a discerning eye focused on upscale indoor-outdoor living

Summer Thornton is the kind of designer who relaxes by doing things most would consider wildly taxing.

She finds drawing floor plans, for example, calming. Which explains why the Chicago-based creative was way ahead in the planning stages when she and her husband, Josh, who is also a principal in her namesake firm, purchased a waterfront piece of property on the west coast of Mexico, in Sayulita.

The surfing mecca, dotted along the coast with serviceable shacks perfectly suited to wave worshippers, is less known for serious architecture. At first, Thornton thought she could save the house that sat on the plot. “Ultimately, it was too depressing, just a slapped-together building that had been sitting there for 30 years,” she says. “I’m not a tear-down kind of girl, but it was clear that all that was worth saving was the house’s front door.”

Thornton had some serious ideas and opinions about the kind of home that should grace this stretch of land hugging the sea. So when it came to finding an architect, she knew she had her work cut out for her. “There aren’t very many who would appreciate a client who has floor plans already drawn up,” she says. But she found a kindred spirit in Enrique García, the Puerto Vallarta– based founder of Enrique García Arquitectos, a firm recognized for coastal modern designs that place a premium on casual, relaxed, indoor-outdoor living.

Thornton didn’t necessarily see herself living in one of García’s clean-lined designs, but she recognized something compelling in him. “His depth of passion for his work is palpable,” she says. “We connected over that.”

While the entire project required almost two years to complete, it took about six months for the pair to get into an aesthetic rhythm, one that deftly responded to Thornton’s admittedly competing desires.

The living space is vertical in the Chicago Victorian she shares with her husband and two small children, so Thornton wanted a horizontal orientation for the seaside villa. High ceilings—like those she has grown accustomed to in their primary residence—were also on her list. “My inspirations were haciendas and colonial Mexican homes, neither of which have the proportions suited to a beachfront house,” she says with a laugh.

But García managed to create a design that is both contextually appropriate and delivered on Thornton’s desires. He focused on negative space and large volumes— there are 14- and 12-foot ceilings on the first and second floors, respectively—and a central courtyard around which he wrapped the structure. “We had the best time working together,” says Thornton.

Indeed, the collaboration was as rosy as the naturally dyed chukum, an ancient Mayan stucco made from the sap of the same-named tree, which envelops all 7,000 square feet of the house, named Casa Rosada by the couple. Waterproof and durable, it stands up to the sun, salt, and humidity—factors Thornton took into account when making choices not only for the exterior but also the largely open-to-the-elements interior. “The entire living room is essentially a covered porch when the doors are all open,” she says.

The designer’s go-to for indoor-outdoor fabric is Perennials, not only because it is mildew- and fade-resistant but also because the color palette stands out. “The whole house is built around fun and relaxation, and that is exactly what we experience every time we come here.”

“It’s easy to find performance fabric in shades suited to the Hamptons and California and Florida, but not so much Mexico,” says Thornton. She fell in love with Perennials’ Whippersnapper in Desert Rose and used it liberally throughout the house. “The built-in concrete sofas in the living room required an enormous amount of fabric, and I wanted it to be forever fabric,” she says. Thornton loves the texture of Sail Cloth so much that she opted to use it in Beach Glass inside, including to make drapes for the children’s rooms.

Casa Rosada was completed just in time for Thornton’s birthday last fall. For the celebration, she and 20 friends put García’s design to the test. “The whole house is built around fun and relaxation, and that is exactly what we experience every time we come here,” she says. Indeed, the designer wants others to visit Sayulita in the same luxurious way and rents out Casa Rosada as a full-service retreat. “It’s like staying with a friend who has a great house in a quaint town and she knows exactly how to indulge you.