CLT offers high thermal insulation properties compared with concrete and masonry.
The U-value of CLT is significantly lower than that of concrete and brick walls (of the same thickness).

Comparison for 20 cm thick wall:
CLT U-value = 0.59 W/m²K
Concrete U-value = 3.2-3.7 W/m²K
Brick U-value = 1.8-2.5 W/m²K
The U-value indicates how quickly heat escapes through a building element (e.g., wall, window, or roof). A lower U-value indicates that less heat is lost through the structure, indicating better thermal insulation.

CLT also has a higher specific heat capacity compared with concrete and brick:
CLT specific heat capacity (c) = 1600 J/kgK
Concrete specific heat capacity (c) = 1000-1300 J/kgK
Brick specific heat capacity (c) = 800-1000 J/kgK
Specific heat capacity measures a material’s ability to store heat and indicates how long the material will release heat after reaching thermal equilibrium. A higher specific heat capacity means the material stores heat better and releases it more slowly to the surroundings.

Moreover, the thermal conductivity indicator (λ) of CLT is lower than that of concrete and brick:
CLT λ = 0.12 W/mK
Concrete λ = 1.5-2.0 W/mK
Aerated concrete block λ = 0.2-0.38 W/mK
Brick λ = 0.64-0.9 W/mK
Mineral wool λ = 0.035-0.045 W/mK
Thermal conductivity (λ) indicates how well a material conducts heat. A lower λ value signifies better thermal insulation properties.