The focus of the present paper is on the investigation of the deformation and forces of an isolated steel beam column sub-frame exposed to localized fire. The investigated frame is modelled using finite element software ABAQUS considering three dimensional solid elements. A sequentially coupled thermo-mechanical analysis, where the derived temperature distribution obtained from the heat transfer analysis used as an input for the mechanical analysis, is carried out. The input heat flux which acts as Neumann boundary condition for the heat transfer analysis is considered from widely recognized handbook of ‘Society of Fire Protection Engineers (SPFE)’ of fire. Elasto-plastic material model is used for steel where the temperature dependent material properties are followed according to the Eurocode 3. Different cases were investigated based on the location of the localized fire source in the floor below the exposed beam. It was observed that for asymmetrical location of the fire source beneath the beam, the rotation for the far end connection to the fire source was always higher than the near end. © 2022 ISEC Press.