Architectural trends are heading the way of outdoor designs that boast low maintenance but maintain high style. Marcus Hiles of Western Rim Properties has seen an emphasis placed on open-air spaces that are both sustainable and reduce utility costs for residents. Eco-friendly, conservation-minded choices like rainwater or graywater harvesting and permeable pavement are put into place by an increasing number of people. Via a rooftop collection system, rainwater harvesting redirects moisture from the air to a well to be treated and repurposed on-site; while graywate recirculates previously used household wastewater to rest rooms and non-drinking purposes including plants and lawns, lessening the need for fresh water and lowering the amount of sterilization. Another novel idea, permeable paving, actually dates back thousands of years to the point where society first developed roads by putting stones in beds over land. The practice allows the water to pass through thin openings between four layers of filtration (paving material, gravel, fabric, sand) before it is absorbed by soil below. Benefits are numberous, and include lowering runoff and pollution, controlling the rush of storm water to gutters and drains, maintaining local groundwater supplies and serving as a skid resistant surface for walkways, patios and driveways. Permeable pavement is aesthetically attractive and often utilizes crushed stone, brick, and recycled concrete.