 This paper investigated the effect of scaling on blast wave parameters for reduced-scale urban blast scenario laboratory experiments. It compared the results from two scales, 75% and 100%, and also compared them to field trials conducted by Gajuski and Cialiki in 2020. The results showed that the lab scale tests were sensitive to factors such as detonator positioning, explosive material, charge confinement slash mounting, building surface roughness, and environment. This article was authored by Sherlyn Gabriel, Jack Denny, Steve Chung, Kim Ewan, and others.