Thoughts on Going Green
Posted on Feb 12th, 2009 by Doug Marsh VP, CR, CAPS, GBP | 0 Comments
Now that going Green is the "in" thing, I wanted to mention some not-so-obvious ways for all of us to accomplish this. The City of Austin Green Building form can be used as a guide to help train your thinking on moving in a Green direction. Consult a Green Building professional for help in interpreting the form and implications.
http://www.austinenergy.com/Energy%20Efficiency/Programs/Green%20Building/index.htm
SITE SELECTION
Where we live is driven by so many different concerns: most notably, commuting, proximity to work and schools, children's activities and friendships, affordability, and beauty. All of these are important and it makes sense that the closer your location is to public transit, shopping and green belts, the less carbon you'll produce simply by driving less. If you choose to live out of the city, driving a vehicle with a smaller engine helps in this regard. Living in an older neighborhood where the utilities have been in place for 25 years supports reuse of housing that is in place instead of supporting new neighborhoods that were recently developed, which, of course, means more burning of fuel. It is a Green way to think and it might not be so obvious.
DESIGN IS KEY
Today, building technology is changing rapidly and it is important to get help in this area. The upfront expense of qualified design will be paid back in short order. The Mechanical, Plumbing, and Electrical components of a home are of paramount importance. For example, recessed cans for lighting are a consumer favorite, however, they are essentially a hole in your ceiling if you currently have a conventional (vented) attic.
In our hot/humid climate, HVAC design and installation is virtually the most important component in a structure. The 2006 energy code mandates Manual J calculations for sizing and design of the HVAC equipment. Manual J is a software program that takes inputs from a house, including the size of windows, type of windows and insulation, and then along with a sister program, Manual D, then gives the ducting size and air flow calculations and equipment size for your home. This is something we really need when replacing equipment and/or ducting, adding on to a structure, or building new. Not only is it the code now, but the payback is enormous and quick. Also, the code mandates windows that are low e-rated and have U and shading coefficient values that are below a certain level. A designer will direct placement, size, and shading as needed for a structure.
Wood sash replacement (keeping the old frame and installing new wood frames that only hold the glass) is a great technique for avoiding a lot of the mess and expense of damaging drywall and interior trim if you have an older home that has wood windows. New additions and houses can be designed to have unvented attics (height above the top of the wall must be 6” to allow for thickness of insulation at this juncture; coordination of ducting installation and spraying foam; furnace must have a sealed combustion chamber; filtered and dampered outside air needs to be brought into a return air location). This is a relatively new technique that puts the insulation (water/soy based foam: www.biobased.net or www.deruiterinsulation.com) against the roof deck instead of on top of the ceiling. Conventional vented attics are a 1940’s technology and contain a lot of moisture, hence the venting needed. The moisture compromises the insulation value on your ceiling by as much as 50%. The City standard for R value in a conventional attic is R 30 however by using foam against the roof deck (approx R 22-5” of foam, give or take) this value can go down to R 22 + because the foam material is virtually impregnable to moisture (perm rate). It also takes up to 22 hours for heat to penetrate this material, so by the time the night cycle arrives the heat has not penetrated (much) into the space. This unvented attic remains 5-8 degrees warmer than the living space below. This is an enormous difference from the conventional 140+ degree attics that we are used to, with compromised insulation values sitting on top of our houses. This makes a decent location for HVAC equipment to be situated including all the ducting which carries the cold air in a only slightly warmed space. The gas furnace does need to be a sealed combustion chamber unit where the combustion air is brought down the same flue as is taking the flue gas out. All of the exhause fans in the house also need to be upgraded to remove moisture throught this new foam insulation and out the roof deck. This solves the recessed can in the ceiling issue as well since the actual can housing is not creating a hole in the envelope. A word of caution is to be noted with these attics; if you are the type of family that never opens your windows year round, you should have a dehumidifier installed in an unvented attic to remove moisture that will accumulate because of the low perm rate of the foam insulation.
Lighting fixtures are another key element that is changing constantly. LED lighting is coming online now and fixtures are available for under cabinet lighting and in overhead decorative types also. Lighting Inc is a local resource for these types of lighting fixtures. www.search52.com/lightinginc.com. The longevity of LED lighting is renowned. Solar panels are constantly evolving in the types of materials used to produce them. The City of Austin provides a generous rebate for installation of a photo voltaic system. http://www.austinenergy.com/Energy%20Efficiency/Programs/Rebates/Residential/index.htm. Electrical design of your service panel and integration with the PV system is critical. Roofing materials are starting to come online that
are thin films containing Photo Voltaic cells. I am not sure of the viability of these products in a hail-prone area like ours.
Using ceiling fans in bedrooms or other rooms to move air for comfort and lessen the load on the AC equipment is very helpful for lowering
energy costs especially if you purchase Energy Star rated fans. Energy Star rating is the way to go for choosing all your appliances and other electronic equipment like computer screens.
INTERIOR FINISHES
I call it "hard flooring"...used wood, tile, polished or stained concrete for your finish flooring material choices. The ongoing sustainability of the finish surfaces in your home or addition relieve the continual "make it and throw it away" aspect of, for example, carpet. The flooring market has exploded and there are enormous amounts of sandable wood flooring products available now including bamboo on a recycled content plank (engineered wood). We forget that using something that will last is one definition of going Green. However there are many choices now for recycled carpet and the quality is continually improving. Cabinets and trim materials are available with components made from managed forests (FSC-certified lumber) http://www.fsc.org/ The plywood in cabinets can be made to minimize off gassing (releasing unhealthy gas from the product). Fine Lumber is a local source for materials of this type. www.finelumber.com Low or non-volatile compound (VOC) paints and finishes are available now to minimize VOCs in the home.
http://www.sherwin-williams.com/pro/green/index.jsp
AGING IN PLACE
Another way to describe this is Universal Design. As certain segments of the population age, the design of their living space needs to accommodate the aging process: vision, mobility, accessibility to name a few issues. What makes this a Green issue is the thinking ahead to avoid tearing out and redesigning again. There are excellent resources for wheelchair usage and Universal Design. http://www.pva.org/site/PageServer?pagename=access_main
Of course using a wheelchair is not what we all are considering, however, designing now for the future is not expensive and quite achievable. So many of our clients say during our preliminary project discussions “we are staying here forever” or “they'll have to take me out in a wheelchair”, so planning ahead can be a no-brainer.
LANDSCAPING AND WATER USAGE
Once again, the City of Austin Green Building Program provides good information on landscaping and water usage:
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