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HomeMy WebLinkAboutRIVER SONG WALDORF SCHOOL - PDP - 11-98 - SUBMITTAL DOCUMENTS - ROUND 1 - BUILDING EXTERIORStrawbale Construction fflciencv & Ti es of Structures Energy efficiency seems to be at the top of moot designers agendas these days. With energy rates moving steadily upward, with no break in sight, our growing global population needs alternatives that will reduce their impact not only on our natural environment, but each other. Strawbale construction offers one alternative that i5 not only attractive, but potentially very cost effective. Tests performed in New Mexico ,., have shown that straw, when packed tightly in bale form ossesses an R-value between p 2.5 and 3.0 per inch. Depending on the orientation of the bale, total values in Strawbale walls of R-65 can be achieved. This value i5 more than triple that of Standard 2x6 framing with fiberglass insulation. When coupled with a good amount of thermal mass inside the building, passive Solar features begin to make a larger difference. Energy Rated Homes of Colorado has tested our homes rating the wall System at the top of it's list in terms of tightness and energy efficiency. What this translates to the homeowner is lower heating and cooling bills meaning more buying power i5 available. It i5 estimated that a Strawbale home will Save one-third the cost of the Structure over a thirty year mortgage, when compared to a Similar Stick -framed Structure. Two types of Strawbale Structures have dominated the Strawbale construction Spectrum. The first type of Strawbale Structure to Show up on the maps were around 1590 in the Sand Hills of Nebraska. These primitive, but efficient Structures were built in reaction to the scarcity of other building materials and a harsh climate. Today we call them "load bearing" or Nebraska Style, meaning that the weight of the Structure above i5 carried by the Strawbalco in the walls. This i5 the Simplest, most efficient type of Strawbale building, but not necessarily the best choice for every building built today out of Straw. In reaction to the limitations in design, people have been combining a post and beam frame with the bales, using them 5trawCrafters as insulation and a5 a Surface for plaster. This type of Structure we call "non -load bearing". Neither type of Structure i5 the best for all CAUMM AM applications of Straw in the construction industry, but rather, each has P.O. Box 1797 We place when attempting to balance the needs of a building with it's Boulder, CO 80306 303/499-1334 inhabitantoand surrounding5. We like to preoent "load bearing", though, Please contact us for any information a5 the option of choice when approaching new projects due to We ease regarding this type of construction and of construction and oaving5ofnatural reoourcco. how we may help you with your project. 5trawbale Construction o & other Common Queotiono When comparing the costs of a 5trawbale to that of a piece of . milled lumber, it becomes very obvious that strawbale construction is potentially more affordable. It has been the direction of the strawbale industry to classify itself as an answer to affordable housing, when in fact it can cost more than other types of construction, depending on r many factors. When comparing strawbale construction to + other types of construction, with the came level of finish, strawbale construction is in fact not much less expensive. A contractor built structure utilizing Strawbaleo as either the structure or insulation is about the same as a stick -framed comparable. The difference though is in the duality of structure that is built. A strawbale house is far superior to it's conventional counterpart in many ways. The increased energy efficiency alone is triple that of a 2x6 framed building, and it's longevity and durability far outperforms them as well. 5y observation, we can see that a house built out of straw requires less maintenance during it's life -cycle, and in fact, we do not know what the lifcopan of one of these buildings is beyond 100 years. Homes still inhabited, 60 to 70 years old are still in fine shape in Nebraska and Alabama. Other common questions that are asked about otrawbale construction have to do with vermin, insects, suitability in different climates, insurance and financing. To answer the first two concerns, the walls are Sealed with plaster, leaving no way for vermin or insect, or water for that matter, to enter. 5trawbale construction has one serious enemy - water in liquid form. When the moisture content in a strawbale reaches above 25% fungus begins to break down the cellulose fibers in the Straw. For this reason we test every bale that goes into a wall, and detail our buildings to shed water effectively away from the bale walls. In humid climates even more attention to detail is required, but no Significant problems have been encountered that were not explained by logical flaws in either the design or construction. AS for insurance and financing, strawbale construction is being more widely accepted, literally daily around the country. We have first hand experience with both major lenders and insurance agencies. This is not to Say though that Sometimes a bit of education needs to take place in order to gain acceptance. We are moving forward in these directions in a Steady fashion that seems to be comfortable for all those involved. �bsgrMSOMMM ARTfM[CMW r P.O. Box1797 Boulder, CO 80306 303/499-1334 Please contact us for any information regarding this type of construction and how we may help you with your pro- � 5trawbale Construction hetico & Environmental Ben Some of the moot attractive features of 5trawbale ' a '�' ;*,• construction are based in it's inherent aesthetic beauty. It i5 the cheapest form of thick- walled construction, and it is this thick wall characteristic that lends this type of material ` to various artistic r interpretations. Corners between two bale walls are usually, although not M neceo5arily, curved and of a freeform nature. The undulating 4 Surface of a plastered bale wall _ has an organic feel unmatched by others forms of natural construction. This organic feel coupled with it's incredible Sound dampening characteristics gives a Sense of natural, grounded security. Walls do not have a hollow feel when touched, leaving inhabitants with a feeling of connectedness to their natural surroundings. The wall Shown above is a sound wall around a backyard in Longmont, CO which abuts a very busy Street. Notice the bancoo and Shelves created by Simply Stacking the bales in different configurations. Bales can also be sculpted with grinders, chaineaws or by hand to achieve any shape or effect desired. 5trawbale construction also interfaces very well with virtually all other types of building systems. Wood, Steel, concrete and especially earthen materials can be placed alongside strawbale construction with either dramatic or more mundane reoulto. The options are virtually limitless. Using a waste material aS the Structure of our buildings can only be good for the environment. Straw i5 the Stalk of cereal grain, and iS usually wasted in most parts of the world due to it's inability to be composted easily. In California, the Straw that iS presently burned annually iS enough to build all of the atmosphere than all of the states power plants, combined! Here in Colorado, Straw i5 primarily used in highway construction to control erosion and aS animal bedding. Remaining straw iS usually wasted in the field, turning bad from weather exposure. To take advantage of this resource we need to educate 5trawCrafters farmers that their waste i5 our home. By teaching them better baling Ab%WWtasrlwNYFbe C#SMUWmW and Storage techniques we could literally create a vast Supply of building aAM&Menits material. Unfortunately, moot of the bales produced each year cannot P.O. Box 1797 be used in a "load bearing" Structure. Boulder, co 80306 303/499-1334 Please contact us for any information regarding this type of construction an,i how we may help you with your proe, 1 5trawbale Construction Safety issues with strawbale r,, y construction fall under the same categories ao conventional types tit of construction, ouch as fire Safety, indoor air duality and •�,, 't t Structural integrity, Tests 9 Y• • performed at Separate laboratories here in the United States and Canada show _ _- --- & . t conclusively that plastered strawbale construction io �0,1110� Superior to Steel and timber construction. ;k The main reason for this characteristic io that their are no air Spaces in the walls that ~' _ channel combustion. Analogies d-1 have been made to throwing a A _ F phone book or log on a fire. AS a x _ matter of fact, an unplaotered strawbale will usually char on the outside, Self extinguishing any fire on it's Surface. Due to factors such as it's superior energy efficiency and the plaster treatment on it's Surface, indoor air duality io also much better in a otrawbale structure than in a conventional counterpart. To begin with, strawbale walls breathe. We do not apply moisture barriers in a otrawbale wall System , giving them the ability to act ao huge heat exchangero. AS cold air paooeo inside, very olowly, it warmo up, and vice veroa in the opposite direction. The fact that these homed are usually oo energy efficient means that no forced air cooling oy5tem is neceooary, except in vey hot climates. A plastered strawbale wall also eliminates the use of fiberglaoo inoulation, drywall, toxic painto and Siding. With the elimination of these componento usually found in typical wood and steel construction wcaloo eliminate the expooure of inhabitanto to these potentially hazardouo materialo. Straw io made of cellulooe, oilica and air. To date, relatively little testing hao been performed that giveo engineero and architecto a clear idea of the true Structural integrity of baled within a wall, but from empirical oboervation thooe of us in the industry know very well what its capabilities are. The house above io a `load bearing" otructure. The Straw io holding up the large roof and floor above, without any Signs of otreoo. Straw doeo have Structural limitationo, and we muot reopect them. Engineero feel that the elaotic nature of otraw will even outperform oteel, timber and concrete during a oeiomic event. But aS mentioned above, more testing needo to be performed. Please move around this structure and read about other advantages of strawbale construction l�rn✓fssdrb/Iri+rs aiera�eY�a�I p�s>�tNr P.O. Box 1797 Boulder, CO 80306 303/499-1334 Please contact us for any information regarding this type of construction an,7 how we may help you with your pro- conventionally built structures. While the plaster surface may develop cracks that will require patching, the underlying resilient structure should be unharmed, and empirical evidence supports this. 5. Comfort and Aesthetics - Homes built of straw bales are warmer in the winter, cooler in the summer, and can drastically reduce the amount of energy required to heat and cool the house. These long-term operating savings should be factored into the total cost of building and owning a home. The thick bales can be used to creative advantage in designing window seats, niches, furniture and many sculptural elements, much like double - adobe, but with much less time, maDerial and labor costs. Traditional wood siding and drywall has been used in conjunction with straw bale wall construction, however, adobe -based plasters or cementitious-based stuccos are most often chosen for lower cost and reducing the environmental impact. Natural earth -based plaster lends itself especially well to owner application, requiring a minimum of special tools or training, although the mix needs to be tailored to the local climatic conditions. The Straw bale project at 3785 Moorhead Avenue in Boulder is a model of this type of construction technique, so it's referred to as a "Demonstration Studio", although it will primarily be used for storage and as a private workshop. Zoning does not allow for commercial or residential use of an accessory structure in this part of the city. The "privacy wall" around the perimeter is for noise abatement; Moorhead Avenue is a very noise - polluted area, especially with Highway 36 in the backyard. Some of the features of this building include: A non -concrete foundation - the overdependance on concrete is wreaking havoc on the environment. There is an extremely high amount of "embodied energy" in the mining, manufacturing process, and in transporting the raw and finished product, after which we have a material that is nearly impossible to dispose of. Several alternatives exist and have been proven in tests and decades of empirical evidence. There is no Fiberglas in the walls or ceiling. Fiberglas material is hazardous, especially to those who manufacture and install it. Straw was stuffed into burlap bags, treated with a natural fire retardant and installed between the trusses in the r� providing approximately K-40 insulation. The walls are 24" straw bales with natural adobe pfaeter. providing K-55 insulationwhile maintaining a healthy breathability factor, straw bale walls work much like a heat -exchanger. This is difficult to achieve with plastic -wrapped, Fiberglas -filled stud walls. Kecycle J pallet wood is being used for the ceiling, which results in an attractive weathered -wood effect. The studio has no drywall, and no products containing formaldehyde or petrochemicals, except for roofing felt and asphalt rolled roofing. The floor is thick clay brick fivers on sand, providing thermal mass, beauty, and high durability, while costing less than carpet, tile, or wood. Natural sunlight will provide all or most of the heat and light• With its back to a busy Highway 36, the straw bale walls are very effective at noise reduction and interior acoustics. They make for excellent music studios or high noise uses. This particular building was somewhat "over built" for its actual use, but built as a demonstration studio to show the viability of Plastered Straw bale Construction. It is hoped that the local building officials will soon approve the use of this "alternative" technique for residential and commercial uses too. The need for practical, affordable, non -toxic, and environmentally sustainable solutions is urgent; the rigid codes that were presumably developed for our safety and health should not be our nemesis, but this is already the case. There are a growing number of people afflicted with "Multiple Chemical Sensitivity' or "Environmental Illnesses". More flexibility needs to be given for allowing the use of recycled materials such as lumber. Factors such as "breathability", "non -toxic materials" and "solar orientation" should be given a higher priority in the code books, but it will continue to take a concerted effort by all of us who want this type of home to live in. StrawCrafters, a company founded in 1994, cpeclalizes in Plastered Straw bale Construction. Information, consulting, technical asslstance, construction, design, and owner -builder support and training are services we offer to those interested in this building technology. Informational books, videos, and other materials, including workshops will be available in the near future to help others build appropriate, healthy, and sustainable homes and other structures. You may reach us by writing to us at the address below, or calling 303-499-1334, -2508 FAX We maintain a growing database of Straw Bale aficionados; if you give ue your name, address, and phone numbers, we'll periodically_ send notices of events or information available. Please be patient, we're just getting started and trying to keep our heads above the straw pile! StrawCraftere - 3785 Moorhead Avenue - BouWar, Colorado 60303 An Introduction to Plastered Straw Bale Construction © 1994 by Tom Luecke & 5trawCrafters - Please copy and distribute freely Plastered straw bale construction originated in the 5andhill5 of western Nebraska during the late 1800's, not long after the horse -powered baler was invented. It was a practical solution in this sandhille region, an area where local wood for lumber was scarce, and the railroads had not yet come through, making imported lumber too expensive for new homesteaders. 5od, although widely used for building homes around much of the Great Plains, war of insufficient quality from the randhills. Meadow grass hay however was abundant, as were tumbleweeds, and both were compressed into baler and made into homer, churches, stores, and schools. 5everal examples of this eariy "Nebraska style" of building structures with baled straw, whereby the bales were fully load bearing, are still in excellent condition and in daily use. Today we have equipment that makes much higher duality baler than those made 70 to 100 years ago. There are abundant quantities of straw, produced as a by-product of harvested cereal grains such as wheat, barley, rye, rice, and oate. This annually -renewed raw material is a natural for creating affordable, safe, healthy, environmentally friendly, and attractive homes and other structures. Modern interest in straw bale construction began about ten years ago, when an article appeared in the December 1984 issue of Fine Homebuilding, about a small straw bale studio in northern California. Since then, many modern pioneers in the field have helped propel this technology to a fairly advanced state where several hundred structures in the states as well as several other countries now exist, and many more are being designed and built. Much work still needs to be done however, in the areas of research and structural testing, to gain building code acceptance in most areas. Tests take time, and are very expensive, but those of us involved in this effort know that it is time, effort, and money well -spent, because this is simply a viable, more appropriate way to build a home. The total environmental impact of the rapid depletion of this planet's natural resources is significant, and there is increasing awareness of this. Combined with the escalating costs of lumber and other conventional building materials, the need for alternatives such as locally -available straw bales becomes even more evident. What are the virtues of building with straw bales? 1. Environmentally sustainable - Using locally available materials reduces the demand on forest products, and on the fossil fuels used to transport these materials, often thousands of miles, across the country. Straw is an annually renewable, abundant and natural resource available locally. 2. Super insulation values - about K-2.4 per inch with the direction of the Straws, and K-3.0 per inch across the direction of the straws. Using 18" wide, 2-String baler results in an K-42 wall; 24" wide, 3-String bales produce an K-57 wall - and this is before factoring in the plaster or other surface finiehl Remember, this iS from a natural, non -toxic material, not from petroleum -based or Fiberglas products. 3. User-friendly/affordability - Which means that more people can help in the building of their own home, and this can reduce total cost. Although it hasn't been all that long ago since average people designed and built their own homes with locally available materials, we've come to believe that it's so complex that we must hire a specialist to do everything for us. Building our own shelter is a basic, even primal urge for most of us. With a little common sense, and some willingness to take risks, we can still play a part in this process, and feel the tremendous reward for being more responsible for our own decisions, especially when it saves money. Although there have been some incredible examples of low-cost homes built with straw bale, it is important to make fair comparisons when seeking total building costs. It requires a lot of planning and hard work to complete any house, but since many people find this method less intimidating, they can do more of the work normally hired out to specialists. 4. 5afety - results of tests conducted to determine fire -resistance conclude that a plastered straw bale wall is significantly more fire-regietant than conventional light -frame construction. There is enough air in the wall to create high insulation values, but not enough oxygen to support good combustion. It's often said that "it's like trying to burn a phone -book'. Under the right conditions any material will burn, but relative to other common building materials, plastered straw bales rate extremely well, and don't release the highly toxic and often -fatal gases, common to synthetic materials upon burning. 5ei5mic testing is, not yet complete, but it is, expected that straw bale buildings are very energy -absorbing, capable of sustaining earthquakes substantially better than River Song Waldorf School Combined Project Development Plan Fort Collins, Colorado Standing Seam Metal Roof Plaster Finish Over StrawBale Construction