Exterior, Wood Siding Material, and House Building Type Doubling the footprint of their home and adding a pool could have placed Shah and Suttles on the wrong side of the city of Austin’s strict impervious cover rules, which set square-footage limits and are intended to protect local water quality. So they installed high-tech Eco-Priora pavestones in their driveway to help capture rainwater runoff. It’s not quite as fancy as the underground storage tank they sought at their first collaboration with Alterstudio, but the strategy allowed them to go green and stick to their design.  Photo 11 of 12 in 1920s Bungalow Plus Modern Addition Equals Perfect Austin Home