Blog Sustainable Home

Please download to get full document.

View again

of 3
12 views
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.

Download

Document Related
Document Description
Green Building Documentary
Document Share
Document Tags
Document Transcript
  The Shape of Things to Come:Goal: Strive for efficient home design within practical limitations of easilyavailable construction materials and methods and minimize impact on theecology of the home site.Principle 1: Volume / Surface Area considerations: If we build the mostvolume with the least surface area we reduce the amount of materialsconsumed in construction and we create an interior space that is moreeasily maintained at a constant temperature and thus reduce the need forheating and cooling augmentation. This is because heat is generally gainedand lost at the interface of the interior and exterior space. All othervariables held constant, less heat is transferred when the surface area isminimized and the volume is maximized. The most efficient geometry isthus the sphere.Is spherical geometry practical for a home? Not really. Easily availablematerials are generally flat and rectangular, meaning that attempts to buildspherical shapes with flat materials, for example geodesic domes, results inmore corners rather than less and also requires cutting rectangularmaterials into other shapes producing many waste pieces. It also requiresmore energy to size materials as opposed to being able to use off-the-shelfsized construction materials. Corners are prime opportunities for heattransfer by conduction and infiltration so spaces with the fewest corners willhave the best characteristics for energy conservation. While a true spherewould have no corners, an approximation with flat materials results in manycorners.One could use a plastic material such as gunnite (blown concrete) to createa true sphere, but this is not practical on many home sites, nor is itconventional or easy construction. Once you make a mistake withconcrete, well, have fun! The best easy geometric appoximation of thesphere with the least corners becomes the cube. Straight vertical wallsenclose the most useful interior volumes and make excellent load bearingforms for roofs. Flat floors work, spherical floors do not. While sphericalroofs shed water just fine, the water is dispersed rather than gathered bythe roof, complicating catch-water conservation strategies. For efficiency,  economy of easily available materials, and practicality, the rectangularcube-derived enclosure beats the sphere.Principle 2. Efficient use of needed resources;- catch-water, passiveventilation: A flat roof on a rectangular enclosure presents a few problemsthat are solved by sloping the roofline. Flat roofs often leak or developponding problems, disperse rather than gather catch-water and aregenerally higher maintenance than sloped rooflines. A sloped roof can alsochannel air in a convection path that improves passive ventilation.Incorporating principles 1&2, the shed structure with generally equalheight, width and length with a gently sloped roof becomes the shape bestaccomplishing our goals. It requires no trusses as do crested pitchedroofs, nor does it create two or more water shedding directions. All thewater flows the same way and can be easily caught. Similarly all theinterior convecting hot air can be released by a single vent surface and theinterior air flow is increased by simplifying and unifying the direction of airflow.Principle 3. Efficient collection of solar energy;- solar gain: The moresouth facing surface area, the greater the potential for passive solar gain.Departure from a square footprint can be advantageous depending on solargain needs. If you need more solar gain, increase the east west dimensionof the home, if you need less increase the north south dimension of thehome. In a cooler geography that needs more solar gain, it is best to havea site that is rectangular and longer in the east / west dimension. If lesssolar gain is needed, the best site will be longer in the north southdimension. This assumes other variables are held constant.Principle 4. Impact on existing flora;- tree conservation: Trees are thelungs of the earth. If trees aren't healthy, soon nothing else will be thatbreathes. In that trees have as much subterranean mass in the roots asaerial mass in trunks and branches, conservation of trees not only involvesreducing branch cutting, but also root cutting. When there are large treesdominating the entire home site, a pier foundation has much less impactthan an excavated poured concrete foundation. Construction on such asite should be done upon piers set into carefully selected perforations of  the ground to minimize root disturbance. Minimizing excavation in generalis a good idea when tree preservation is a goal. Tree preservation shouldalways be a goal. Trees improve air quality, aid in summer cooling throughtranspiration, moderate winter wind, provide privacy in high populationdensity areas and provide wildlife habitat.To be continued.....to see practical implementation of these principles in a real physicalstructure see my photo album, The New Home copy this link: http://www.facebook.com/album.php?aid=21816&id=1432094474&l=12105e9d90
Search Related
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks