|sustainable materials and design||<– Date –> <– Thread –>|
|From: Tom Lent (tlentigc.apc.org)|
|Date: Mon, 4 Nov 1996 22:36:17 -0600|
Hereis the latest update of my writeup (those of you on cohousing-l saw an earlier version of this a month or two ago). Use and replicate it as you see fit (not for profit and with proper attribution, of course): SUSTAINABLE MATERIALS USE & DESIGN IN BERKELEY COHOUSING Successes and failures lessons learned November 1, 1996 by Tom Lent It has been a priority to find ways to maximize our use of environmentally sound materials and design in this project. We have had several successes and several disappointments as we have succeeded in including some elements and not others. Our failures are in part due to the nature of the state of the art, in part to budget limitations (we are working under affordable housing price guidelines as well as our own pocketbook restrictions) and in part to our own lack of time and energy to pull off this whole crazy project and do all the research we would like to do to push the envelope on sustainable material use. Our sustainability concerns started before construction with the site prep and demolition. We salvaged and milled the acacia trees that we had to cut down (they were nearing the end of their life, developing serious cracks and crown root rot. and starting to come down of their own accord). We plan to use the lumber for interior stairways. A large palm tree that needed to be removed was transplanted to a new home - a spectacular process involving a large crane hauling the gigantic 40' tree over a house and a set of power lines. We also saved a redwood that we had been told would have to come down because of its proximity to a house. Digging to explore its root structure allowed us to determine that it was coexisting with the house satisfactorily. It also resulted in a water line break that led to reshingling a section of house and cost us a total of $1000 to repair. We salvaged lots of bricks, tile and lumber from the demolition process. The contractor source separated most of the wood and concrete and asphalt roofing material for recycling. Old sinks, toilets, windows and a water heater saved from the demolition got us enough exchange credit at the local salvage yard to obtain several windows and doors we needed. We designed our site drainage to percolate as much rainwater back in to the ground as possible rather than sending it in to the storm drain. Starting from the ground up, we are using concrete with a 15% mixture of fly ash - a recycled waste product from coal fired power plants - replacing some of the energy intensive cement. We'd rather not have the coal fired power plants, but if they must burn the coal, at least we can make good use of the waste. In addition, the fly ash also makes the concrete a stronger and more workable product. Our mud sills (the wood that goes directly on top the concrete foundation) will be treated with "ACQ Preserve", an alternative to the usual copper-arsenic (ACA or CCA) preservatives. We investigated the possibility of using straw bale construction but returned to traditional stick framing because of severe space constraints in our urban infill situation. We could ill afford to give up the 100 square feet or so that the thick bale walls would occupy in each unit. Additionally, we needed to build two story buildings to get the most out of our space. Since Berkeley had yet to approve a one story bale house, starting with a two story house was too large a leap. We will be using straw bale construction for our sound wall at the end of our property that fronts a noisy busy street. We also investigated straw panel options, but could find no manufacturers that were actually in production at the time we were completing our design. We came close to using a product called Thermoply for shear sheathing made of recycled cardboard covered with foil, but it has not yet gone through certification testing for this earthquake zone. Maybe next year. Turning to stick framing we hoped to use sustainably harvested wood for the framing and sheathing, but during the planning stages of the project, we could find sources for neither. As we started construction we found plywood for sheathing was still not available at all, but Douglas Fir for framing - while not available predried off the shelf - could be purchased milled to order and delivered green. Alas, since we didn't have time to store it ourselves to dry, we could have serious moisture problems. This could mean problems with warping wood and popping nails down the road. Hem fir was available kiln dried, but still had long lead time (4 weeks) for delivery. By the time we discovered this availability, it was too late. We were under construction, rushing to beat the winter rains and even a couple of week delay in our schedule at that point could have been disastrous. Lesson learned: Try hard to get your lumber list together before the construction loan close so you can place your order at the earliest possible time as soon as the money is committed. Oh well, as Katie says, at least we are part of creating the demand for those who will follow us. Some day soon it will be available dried off the shelf if enough of us request it. We will use certified sustainably harvested redwood for the decking. We are using carpet either made from recycled materials or from wool with jute backing. The carpet pad is made from recycled material. Our flooring is made from bamboo instead of wood in all units except one in which we are using hardwood flooring salvaged from another older unit. On the roof we will use fiberglass composite shingles, much less toxic than standard asphalt shingles. We are using paints with no VOCs inside and are investigating the use of recycled paints on the outside. We wanted to avoid using PVC in the plumbing due to the toxic nature of its production and disposal and concerns about its impact on water quality. We ended up splitting - spending the extra money for copper for the water service work, but resorting to PVC (instead of clay) for our sewer work for price and resilience reasons. Our energy designs, both in heating and in lighting far exceeds the state standards with good insulation and efficient windows, including fully retrofitting all of the existing buildings to the same level of energy efficiency required of the new buildings. We designed the buildings with more glass area on the south side to capture solar heat, extra thermal mass (through the use of thicker sheetrock) to absorb the solar heat and smaller window areas on the north to cut down heat losses. Heating efficiency is increased in our design by using a single water heater in each duplex to supply all space heat and hot water for both units. Three of the new units use radiant slab system to deliver space heat. We are trying to go the extra mile in conserving electricity and water as well. We are designing with compact fluorescent lights wherever possible and using water saving toilets, showerheads and faucets. We will have plumbing installed to the roof and strong south facing roofing structures to support future solar water heating options on all new units. We are using photoelectric smoke detectors instead of radioactive ones The best news is that we are doing all of this at little or no extra financial cost - in most cases just the cost of our time to research, find and evaluate the options, an important consideration in this project with serious price constraints. Of course, the project inherently has positive environmental impacts beyond these design and materials issues. As urban infill near downtown Berkeley and on bus and subway lines to downtown San Francisco, we are providing more housing that is walking and mass transit friendly. By our community orientation (common meals, shared child care, group social activities), we cut our needs to drive and to own more redundant appliances (like washing machines) dramatically. We recycle every material we can. Living in community makes it easier to pool our resources to handle the materials that are not picked up at curbside. We compost all of our food waste for use in our gardens and are exploring permaculture options for our post construction landscaping. For more info about how to join our community, contact us at 510/549-3749. To chat with me about sustainable design and materials, e-mail me via CoHousing-l or directly at "tlent [at] igc.org". RESOURCES: My bible and yellow pages for sustainable construction materials was the Architectural Resource Guide, prepared by members of the Northern California ADPSR (Architects, Designers and Planners for Social Responsibility). It includes excellent descriptions of the pros and cons of different approaches as well as extensive regional and national contact information to reach manufacturers and distributors of the materials. To order a copy, send $15 ($12 for the book plus $3 shipping and handling) to ADPSR, P.O.Box 9126, Berkeley, CA 94709-0126. Also very useful are some of the computer databases of sustainable materials, such as the Sourcebook from EcoLiving International in California at 510-452-0500. Energy Efficiency and Renewable Energy Clearinghouse is a good toll free source of information on energy efficient design at 800-DOE-EREC sponsored by your tax dollars. Fly Ash should be available through RediMix and other local concrete distributors. If they are not familiar with it, contact Pozzolanic International in Washington at 800-416-5171 or Mineral Specialties in Montana at 406-656-2334. ACQ Preserve treated wood should be available through local lumber yards. For help finding a local distributor, contact Chemical Specialities Inc., in North Carolina at 800-421-8661. Straw Bale information is available from Out On Bale in Arizona at 520-624-1673. Sustainably harvested wood is available through EcoTimber in Berkeley at 510-549-3000 and a growing number of other suppliers. Ask your local lumber yards first. If you can't find a source of certified lumber in your area check with the certifiers: Rainforest Alliance in New York at 212-677-1900 and Scientific Certification Systems in California at 510-832-1415. Fiberglass composite shingles should be available through local roofing suppliers. Recycled plastic carpet is manufactured by Shaw Industries in Georgia at 800-441-7429. Call for distributors. Wool & other natural fiber carpets are available from Hendrickson Naturlich Flooring in California at 707-824-0914. Bamboo flooring is available in the Bay area through the Berkeley Design Center at 510/652-6064 here in Berkeley and Smith & Fong at 415-285-8230 in South San Francisco. Recycled paint is made by E-Coat Recycled Paint Products in California at 916-920-0550 and distributed by Kelly-Moore. Photoelectric smoke detectors are made by BRK Electronics, model 2839. **************************************************************************** Tom Lent * 2220 Sacramento St * Berkeley, CA 94702-1907 email: tlent [at] igc.org * phone: 510/845-5243 ****************************************************************************
Sustainable materials and design Tom Lent, September 25 1996
- sustainable materials and design Tom Lent, November 4 1996
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