Latest architectural trends have extended to outdoor designs that boast low maintenance and high style. Marcus Hiles has seen the rise in demand for sustainable and affordable open-air spaces. Eco-friendly, conservation-minded choices such as rainwater / graywater harvesting and permeable pavement are leading the way. Utilizing a rooftop collection system, rainwater harvesting redirects moisture from the air for storage in a well to be treated and repurposed on-site; graywater takes previously used domestic wastewater and recirculates it for restrooms and non-drinking purposes, decreasing the need for fresh water and lowering the amount of sterilization. Permeable paving is another seemingly novel idea for environmentally minded construction. The practice allows the rain to pass through small openings between four layers of filtration (paving material, gravel, fabric, sand) before becoming absorbed by the earth below. Its benefits include lowering runoff and pollution, controlling the flow of storm water to gutters and drains, replenishing local groundwater supplies and providing a skid resistant surface for walkways, patios and driveways; their many attractive patterns often incorporate crushed stone, brick, and recycled concrete.