The thesis presents a study of heat transfer in three selected details of Qbiss Air façade system, produced by Trimo d.d. These details are as follows: (A) lateral contact of two façade panels in the corner, facing inwards, (B) contact of two façade panels in the corner, facing outwards and (C) the façade panel - foundation base junction. Two-dimensional numerical analysis using finite element method was used to simulate steady-state heat transfer at described junctions. Complex geometry of all details was designed using Catia V5 software ragarding to standard SIST EN ISO 10211. Numerical analyses were carried out using software package Ansys 13.0 and optimal finite element meshes of details were determined. Based on the results of numerical analysis, linear thermal transmittance (?) and temperature factor at the internal surface (fRSi) were calculated for each detail. These factors are the basis for the calculation of transmission heat transfer coefficient (HT) of buildings with Qbiss Air façade system. Based on the obtained results, possibilities for eventual future improvements of details were suggested.