Soft Stories

A soft story is defined as a building level that has a lateral stiffness less than 70% of the stiffness of the story above it. An apartment complex with a row of garages below the first level is a fine example of this scenario. Another example is a house supported by stilts on a mountain slope.

Mitigation of the soft story weakness involves the addition of more bracing or sheathing on the soft level in a manner similar to that of cripple walls or unreinforced masonry columns. Though it is more difficult to sufficiently reinforce a soft story, it can be done, in turn reducing damage to structures and the lives within them.