By Marice Richter
Green Right Now

With spring just around the corner, the time has come to dust off plans for those home improvement projects that have been shelved during the cold weather months. No doubt, those plans involve some outdoor projects and perhaps some renovation inside, too.

Whatever you’re planning, why not consider using rock or stone? These are plentiful, long-lasting, durable materials that have multiple functions and can be used in eco-friendly ways.

Rock or stone structures have existed as far back as antiquity. The pyramids in Egypt as well as those built by Aztec Indians were constructed entirely of rock and stone. And then there are the grandiose Cathedrals and palaces, dating back centuries to medieval times, that still enthrall thousands of European visitors each year.

Because of their durability, rock and stone have long been regarded as a great building material for retaining or perimeter walls, garden waterfalls or for homes themselves. Besides functionality, rock and stone are attractive and remain a popular choice  — in real and faux versions — for fireplace surrounds, countertops and exterior home facades.

But just because these materials are found in nature, doesn’t make them eco-friendly in all situations.

“You have to consider where it’s coming from, ” said John Heffner, a production associate for LEED-accredited contractor Allen and Associates of Santa Barbara, Calif. “If a granite countertop is cut in China and traveled a long way, it might not be too green.

“And you have to consider the quarrying process and what that did to the environment during and after the granite was mined,” he said.

Locally gathered rock or stone are considered the most eco-friendly as long as they were mined in a way that protects the environment.

“Rock that was stripped from a river and upsets the aqua culture is not environmentally-responsible,” said Jane Martin, founding director of Plant*SF in San Francisco and a LEED-accredited California architect.

But rock and stone – particularly smaller pieces gathered locally in an eco-sensitive way – are useful for a variety of projects. Plant*SF uses crushed rock as ground cover around plantings as part of its mission to add more green, permeable landscaping to a city with an overabundance of concrete paving. (See the picture, at top, of Marina District neighbors using stones to augment a tree-planting effort; above, permeable rock borders and greenery on 18th Street in the Mission District.)