Buildings that sit very close increase the possibility of knocking into each other during the quake, causing more damage from mutual impact than would have been sustained from each building being shaken individually. Buildings constructed with a gap between them are less likely to damage each other.
Steel and wood afford more flexibility than other building materials. Flexible materials are important because they absorb the energy rather than shattering from it. Cantilevered construction elements help as well because they have support at only one end, allowing for less rigidity. Pipes and other conduits should have flexible sections that allow for unexpected movement.
Base isolators are design elements in a building's foundation that absorb shocks coming from the ground and reduce damage from the quakes. These building bases cushion the structure and dissipate the shock. They can be plates that produce no friction, allowing mobility in the quake, or they can be pads on which the building sits.