The calculation of the energy efficiency of buildings is carried out on the basis of the measurements (external and internal building temperature, emissivity of the outer and inner surfaces of the wall) and the appropriate construction parameters. The aim of this paper is to show the impact of changes of emissivity and reflectivity on the accuracy of the temperature of building materials and heat flux construction. The experiment was performed using Infrared Thermal Imaging Camera FLIR T 420. The samples are building materials- brick, fir, tin and some type of marble. Analysis of the generated images is done in FLIR Tools software package. We estimated equivalent temperature of objects as functions of emissivity end reflectivity non transparent objects. Obtained experimental results show that the equivalent temperature increases if emissivity decreases, and equivalent temperature increases if reflectivity of object increases.