Thermory Ownership Changes Hands as Estonian Holding Group Takes Majority Stake

Thermory, the Estonian manufacturer that has become the dominant global supplier of thermally modified wood, has a new majority owner. UG Investeeringud, an Estonian holding company that previously held a minority position, acquired the majority stake from Livonia Partners in a deal that closed on July 9, 2020, after receiving Estonian competition authority approval.

The Company

Founded in 1997 (originally as Brenstol), Thermory has grown into the world's largest producer of thermally modified timber, a material prized for its durability, moisture resistance, and dimensional stability. The company's products span sauna interiors, exterior cladding, decking, and architectural applications, shipped to over 50 countries from multiple manufacturing facilities in Estonia and Finland.

The thermal modification process, which heats wood to extreme temperatures in a controlled environment, has made Thermory's products the go-to material for premium sauna construction worldwide. Sauna-grade thermowood (interior paneling, bench materials, exterior cladding for outdoor structures) accounts for a significant share of the company's revenue.

Every major sauna manufacturer we supply to is asking for more volume, and lead times are stretching.

Thermory at a Glance: Founded 1997 in Estonia. Multiple manufacturing facilities across Estonia and Finland. Products shipped to 50+ countries. Estimated ~17% of the global thermowood market at the time of the deal. UG Investeeringud takes majority stake from Livonia Partners (closed July 2020).

Why It Matters

The ownership change signals confidence in Thermory's growth trajectory. Demand for thermally modified wood has been rising steadily, driven by the outdoor sauna boom and growing preference for sustainable, chemical-free wood treatment methods. UG Investeeringud, which had been a minority investor, is now positioned to drive the next phase of capacity expansion.

Competitive Context

Thermory's closest competitor is Lunawood, a Finnish thermowood producer with roughly 15% of the global market. U.S.-based Bingaman & Son Lumber also produces thermally modified products, though primarily as part of a broader Appalachian hardwood operation. Several Asian producers are also entering the market at lower price points.