Calculations and resulting data are described which are intended for use in estimating the protection afforded by buildings against nuclear radiations emitted from a nuclear burst in the first half minute or so. The basic source configuration is that for which one assumes equal likelihood of the explosion occurring on a ring of elevation 30 deg above the horizontal, relative to a structure location on the ring axis. Source spectra and angular distributions corresponding to large distance (≳1 mile) from burst point to structure are used. As sources we discuss here only gamma rays from fission products and from neutron interactions with air molecules.