Fluent in both interior design and construction, Sims Mackenzie Design Group is trusted by high-performing executives, entrepreneurial families, and industry leaders to design high-end family homes that offer rest and reprieve.

At the helm are co-founders Toni Sims and Kelsey Mackenzie, two distinct yet deeply aligned voices in the world of high-end residential design. Toni, a respected industry force with over two decades of experience, is known for her deep construction knowledge and long-standing relationships with Florida’s top builders and architects. Kelsey represents the next generation of design leadership—fresh, strategic, and deeply personal. 

Together, they offer a rare blend of vision, precision, and leadership that few firms can match. Their nationwide portfolio spans custom new builds, large-scale renovations, and legacy vacation homes —each a seamless expression of their clients. Over the years, they have been quoted, interviewed, and featured in The New York Times, The Wall Street Journal, and Luxury Home Quarterly.

“Our Aesthetic is our people.”

Sims Mackenzie Design Group

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