Large Square Sauna No. 40 – Natural (With Window) | Thermory

The Thermory Square Sauna No. 40 is a professional-grade 4-person outdoor sauna meticulously engineered for architectural luxury and long-term durability. Constructed from thermally modified Nordic spruce, this model is the ideal solution for homeowners seeking exceptional rot resistance and a spacious interior with seven feet of vertical headroom for maximum comfort. Its expansive full-front tempered glass and signature wide back window invite natural light and panoramic views while maintaining superior heat retention through 1.57-inch thick boards and a sturdy, weather-resistant build. By combining a modern square-barrel aesthetic with deep ergonomic benches and an included all-weather rain jacket, the Square Sauna No. 40 delivers the industry-standard balance of contemporary design, high-performance insulation, and authentic Finnish-style wellness for any premium outdoor retreat.