Activity concentrations of 226Ra, 232Th, and 40K in building materials used for the construction of a neutronics laboratory at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria have been determined using γ-ray spectrometry. Radon and thoron exhalation and emanation were determined using an electronic radon detector connected to a closed loop vessel. The materials studied include cement (CMT), sharp sand (SPS), plaster sand (PLS), concrete bricks (CBK), and gravel aggregate (GAT). The ranges of the measured activities (Bq kg−1) for 226Ra, 232Th, 40K, and thoron were determined and presented. The annual external radiation dose (mGy) of the samples ranged from 0.148 to 1.082 with a mean of 0.77. The radon emanation coefficient of the samples ranged from 0.36 to 3.88%. The highest estimated radium equivalent concentration for the samples is 46 ± 4 Bq kg−1 and is comparable with the reported values for many countries in the world. These radiation values can contribute to background radiation that should be taken into consideration for its effect on research results and facilities resident in the building. The values obtained are also within acceptable levels and suggest that the use of these materials does not pose radiological hazard.