An emerging solution among rapid, low-impact, and reversible retrofit strategies is the implementation of external additive structures or exoskeletons. Most current research emphasizes non-dissipative steel exoskeletons, such as diagrids or steel braces, while comprehensive design procedures for dissipative exoskeletons remain underdeveloped. This study introduces a design procedure for the seismic retrofitting of RC buildings using dissipative exoskeletons. The proposed strategy is initially applied to a real-world school building and subsequently validated through nonlinear time-history analyses with various input ground motions.