The report is in a format suitable for a prototype guide for architects and engineers use in slanting new building designs toward basement construction of shelters against 15 psi (free field) nuclear blast overpressure and associated including seven case studies. Four were for closed shelter and three for open shelter. The objective was to provide the prescribed protection level at an additional construction cost of no more than 6 dollar/sf of shelter space (based on January 1968 costs). The cost limitation could not be met using only part of a basement, but was achieved in three full basement shelters, one medium and one very large open shelter and one large closed shelter.