For the constructions of wooden buildings are required good mechanical properties and good thermophysical parameters. We designed an alternative instead standard spruce construction element - a combined glued laminated timber beam made of beech and paulownia. The beams were in 3 variants of 3 samples, with a constant height of the central zone of paulownia 90 mm and a variable height of the edge lamellas of beech: 20 mm, 30 mm and 40 mm. We performed bending tests according to STN EN 408, number of beams 9, the results were: local modulus of elasticity in bending 13 798 MPa (var. 7,0%), global modulus of elasticity in bending 10 231 MPa (var. 7,1%), modulus of rupture 43 MPa (var. 21,7%), share modulus 199 MPa (var. 18,5%). The values are given converted to sample moisture wabs=12%. Using Anova analysis, we found that the height of the beech lamella did not have a significant effect on the mechanical properties of the beams. The beams failed in shear in the middle - in the paulownia zone. A 30% proportion of beech wood, distributed along the edges in a combined glued laminated timber, is sufficient. The density of absolutely dry beech and paulownia wood were ρ0=674 kg.m-3 and ρ0=219 kg.m-3, respectively.