This paper describes a numerical method of calculating the fire resistance of load bearing reinforced concrete walls. Each wall is divided into a number of segments of height and elements of thickness. The calculated temperature profile through the wall gives the temperature in each element which is used with the constitutive relationships and mechanical properties to predict structural behavior. The model can consider a range of boundary conditions including pinned, fixed and partially fixed ends. It is shown that walls with a small amount of end fixity top and bottom have very good structural behavior under fire exposure.