Nice try, interesting idea, but how much difference would this make in quakes with vertical accelerations of over 2G and vertical displacements of well over 3 cm such as I have experienced recently living in Christchurch? Well built houses already survive these events (though they may be damaged). We often hardly notice quakes of the intensity shown in the demo, we have had so many. The higher frequencies shown on the chair rig are often filtered by ground elasticity which in turn tends to give rise to a vertical component, likely to be over 3 cm if the intensity is in the range likely to cause damage. The waves sweeping across the ground are quite obvious. It may be useful for houses on rock in quakes with no vertical component. The quakes which do most damage here usually seem to have a significant vertical component.