I’ve had a lot of conversations lately about how “big” seismic loads actually are  compared to gravity loads under NBCC 2020 / NBC(AE) 2023 – especially outside the obvious high-seismic pockets. So, I put together a rule-of-thumb view of base shear as a percentage of building weight (V/W)  by Seismic Category (SC1–SC4)  and ductility level  for typical  regular buildings (normal importance, NBCC equivalent static): 🔹 SC1 – Very low seismic Ductile systems: ~1–2% of W Moderat