[en] A formula on the gamma radiation dose rate in buildings as a function of the thorium, uranium and potassium concentration in the building material is derived in the form of P=(5,4x106ksub(T)+12,6.106ksub(u)++27,7.102ksub(K)) mrem/year, where P is the dose rate and k with the indices T,U,K, is the concentration (g/g) of the thorium, uranium and potassium in the building material. (author)