noun
earthquake resistance; seismic resistance
Technical term used in engineering, architecture, and construction to describe how well a structure withstands earthquakes.
この建物は耐震性が高い。
This building has high earthquake resistance.
耐震性を向上させるための改修工事が行わ
Renovation work was carried out to improve seismic resistance.
免震 means 'seismic isolation', a technique to decouple a building from ground motion, whereas 耐震性 is about the inherent strength to resist shaking.
Compound of 耐 (resistant) + 震 (earthquake) + 性 (property, -ness). A modern technical term.