This paper continues my work [1–3] toward developing a set of quantitative descriptors of non-aeroelastic shielding by normalizing wind-tunnel data compiled from multiple sources [3–11]. The normalization technique reduces the data to a set of shielding factors, which simplifies comparison of shielding data collected over a broad range of testing techniques and configurations. The shielding factors for a structure located in the wake of an identical upstream structure have been found to be most sensitive to separation distance building aspect ratio, windflow turbulence characteristics and wind angle of attack. This study begins to quantify the influence of the first three of these variables.