Tonic Design Studio is a full-service interior design practice specializing in high-end residential interiors — with a focus on new construction and large-scale renovations. We approach each project as a collaboration, integrating seamlessly with architectural and building teams from concept through completion.

Our work is rooted in clarity, cohesion, and context. Every detail is considered. Every decision is intentional. The result is a home that reflects not just a style — but a way of living.

Born in South Africa, Willem Stear brings a global perspective and over two decades of experience to each project. His work spans private residences across the US, Europe, and South Africa — blending a sharp design sensibility with cultural depth and spatial clarity.

Based in Atlanta, Willem leads Tonic Design Studio with a focus on high-end residential interiors for new construction and large-scale renovations. Known for his calm approach, intuitive detailing, and collaborative mindset, he partners closely with builders, architects, and clients to create homes that are as thoughtful as they are timeless.