30 Apr 2009

How Green is my Granite?

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Do you like a challenge? Do you tackle the daily crossword or sudoku puzzle and celebrate a triumphant victory? I love challenges but few puzzles parallel the thrill or complexity of a residential design/construction project. Like the client who calls and says, “Hello, I am interviewing architects and I need an architect who can make my 3,000 square foot house respond to my every lifestyle whim, on my steep and heavily forested lot, with top of the line appliances and finishes and full perimeter porches and all within my budget of $80/SF. Oh, and while you are at it, make my house ultra-green.” I waited a moment and asked, “Is that all?” It is challenging to create a personalized home that blends with the environment, but the green buzz adds a new dimension to design and construction that is difficult to quantify and integrate.

To integrate green building into a home design, I study green guidance from reputable sources such as the National Association of Homebuilders, US Green Building Council and Build San Antonio Green and they each have inter-related strategies to help design and construction meet federal, state and personal green goals. While none of the systems offer a product checklist to rate individual product greenness, they all embrace resource conservation or what green advocates may refer to as “carbon footprint” to assess a product or building’s environmental impact. When advocates assess a carbon footprint, they investigate how much energy it takes to create, use and dispose of the building or products throughout the lifecycle. The questions they ask are:

•    How is the product made?
•    Of what material is it made?
•    How far is it transported?
•    How long does it last?
•    How easy is it to maintain?
•    Is it healthy?
•    How is it disposed?

Let us unofficially grade a product everyone is familiar with — a granite countertop. We are grading relative greenness based on how much energy it consumes from initial creation to disposition.

How is it Made? Granite is mined in open-pit quarries throughout the world. Mining a granite boulder requires heavy equipment to drill, blast and cut the stone. After extraction, the miners slice the boulders into slabs and grind the slabs to create a smooth finish. Mining and manufacturing is destructive, consumes significant energy and time. Granite receives an F for its adverse impact on the environment because it destroys natural landscape at a high energy and labor cost. We would grade it higher if it used recycled material or was easier or less expensive to mine.

Of what material is it made? Granite is a natural igneous or metamorphic rock which means it forms naturally deep in the earth under heavy pressure. Granite receives an A for its natural formation which consumes no man-made energy or resources.

How far is it transported? Most granite installed today is Asian granite because supply is plentiful and less expensive than granite mined in Italy or the United States. The quality is also good, but the transportation impact is significant. Miners load slabs on trucks, transport the slabs to docks, load the slabs on ships and transport it across the ocean. When they arrive in the port, more people and vehicles unload the ships and load more trucks/trailers to transport slabs to your local supplier. Granite receives an F because it is transported long distances and consumes significant man and natural resources. We would grade it higher if it was mined locally.

How long does it last? Granite is strong, offers excellent scratch and burn-resistance and is resistant to decay or rot. Granite receives an A because it will perform and outlast most other building components.

How easy is it to maintain? Granite is easy to clean and requires no special cleansers, but since it is a natural rock it must be sealed routinely to prevent absorption. Some granite with limestone content can stain if in contact with citrus juice. Granite receives a C because it requires regular maintenance and may stain under normal use. We would grade it higher if it was naturally cleansing, resisted stains and required no maintenance.

Is it healthy? Granite may contain a hidden enemy – radon or an applied enemy – sealer. Some granite may contain radioactive materials which may emit radon. The EPA suggests radon levels exceeding 4 picoCuries/Liter require remediation, but warns lower levels may pose a risk. EPA tests measured highest concentrations in reds, pinks and purples but suggest all colors may, but do not necessarily, contain radioactive material. This does not mean the granite countertop is poisoning your home. Granite comprises a small area in the home and radon levels may be insignificant. Designing the HVAC system to increase air changes may remediate radon emission as well. If you are concerned about radon, test the countertop. Also, the surface sealer may contain volatile organic compounds (VOC) that irritate respiratory passages. Selecting an earth-friendly and low-VOC sealer solves the problem. Granite receives a C in the health category because radon and VOCs may compromise indoor air quality. We would grade it higher if it improved indoor air quality.

How is it disposed? Granite is long-lasting so it never needs to be replaced, but if an owner wants to replace granite, it is a reusable and recyclable product. Owners or builders can reuse a demolished slab in another project or cut a slab into smaller pieces to use as tile, backsplash, table top or accent pieces. Another option is to crush the granite and recycle it as paving walkway or driveway paving material. Since slabs are large, heavy and strong they are challenging to remove, relocate or crush, but it is a reusable product. Granite receives a B because disposition can be easy, but requires work. We would grade it higher if it was readily reusable.

Overall, granite is a fair green product because it is natural and long-lasting, but is difficult to mine and transport. If my goal was a ultra-green product, I would not choose granite because its environmental impact is worse than possible alternatives. Granite is one product decision in an entire home. Using granite does not mean the home is wasteful or earth-unfriendly, but if your goal is maximum greenness then you must assess the granite countertop lifecycle compared to alternative countertop products (quartz, laminate, compressed paper, glass, tile, steel) so you can decide which product best fits your design/construction puzzle.

This is an article I wrote for Moving On!, a Boerne Real Estate Magazine, published in April 2009

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About the Author


Your Architect is Eric Faulkner -- an architect licensed in Texas & Oklahoma with 28 years experience in design, construction observation and life.