sustainabilty in building materials and techniques in building materials and techniques unit 1...
Post on 10-Apr-2018
Embed Size (px)
SUSTAINABILTY IN BUILDING MATERIALS AND TECHNIQUES
UNIT 1 INTRODUCTION TO SUSTAINABLE BUILDING MATERIALS 10 Hrs.Introduction to sustainable building materials, qualities, use, examples - Natural building materials, locally available and locally manufactured materials, bio materials - Salvaged and recycled materials -Non toxic materials: low VOC paints, coating and adhesives.
Sustainable building materialsThe concept of sustainable building incorporates and integrates a variety of strategies during thedesign, construction and operation of building projects. The use of green building materials andproducts represents one important strategy in the design of a building. Sustainable building materialsoffer specific benefits to the building owner and building occupants:
Reduced maintenance/replacement costs over the life of the building. Energy conservation. Improved occupant health and productivity. Lower costs associated with changing space configurations. Greater design flexibility.
Overall material/product selection criteria: Resource efficiency Indoor air quality Energy efficiency Water conservation Affordability
1. Resource Efficiency can be accomplished by utilizing materials that meet the following criteria: Recycled Content: Products with identifiable recycled content, including postindustrial
content with a preference for postconsumer content .Natural, plentiful or renewable: Materials harvested from sustainably managed sources
and preferably have an independent certification (e.g., certified wood) and are certified by anindependent third party.
Resource efficient manufacturing process: Products manufactured with resource-efficientprocesses including reducing energy consumption, minimizing waste (recycled, recyclableand or source reduced product packaging), and reducing greenhouse gases.
Locally available: Building materials, components, and systems found locally or regionallysaving energy and resources in transportation to the project site.
Salvaged, refurbished, or remanufactured: Includes saving a material from disposal andrenovating, repairing, restoring, or generally improving the appearance, performance, quality,functionality, or value of a product.
Reusable or recyclable: Select materials that can be easily dismantled and reused orrecycled at the end of their useful life.
Recycled or recyclable product packaging: Products enclosed in recycled content orrecyclable packaging.
Durable: Materials that are longer lasting or are comparable to conventional products withlong life expectancies.
2. Indoor Air Quality (IAQ) is enhanced by utilizing materials that meet the following criteria:Low or non-toxic: Materials that emit few or no carcinogens, reproductive toxicants, or irritants as demonstrated by the manufacturer through appropriate testing.
Minimal chemical emissions: Products that have minimal emissions of Volatile OrganicCompounds (VOCs). Products that also maximize resource and energy efficiency whilereducing chemical emissions.
Low-VOC assembly: Materials installed with minimal VOC-producing compounds, or no-VOC mechanical attachment methods and minimal hazards.
Moisture resistant: Products and systems that resist moisture or inhibit the growth ofbiological contaminants in buildings.
Healthfully maintained: Materials, components, and systems that require only simple, non-toxic, or low-VOC methods of cleaning.
Systems or equipment: Products that promote healthy IAQ by identifying indoor airpollutants or enhancing the air quality.
3. Energy Efficiency can be maximized by utilizing materials and systems that meet the followingcriteria:Materials, components, and systems that help reduce energy consumption in buildings andfacilities.
4. Water Conservation can be obtained by utilizing materials and systems that meet the followingcriteria:Products and systems that help reduce water consumption in buildings and conserve water inlandscaped areas.
5. Affordability can be considered when building product life-cycle costs are comparable toconventional materials or as a whole, are within a project-defined percentage of the overallbudget. (See Environmental and Economic Assessment Tools for links to resources.)
Three basic steps of product selection - Product selection can begin after the establishment ofproject-specific environmental goals. The environmental assessment process for building productsinvolves three basic steps.
Research Evaluation Selection1. Research. This step involves gathering all technical information to be evaluated, including
manufacturers' information such as Material Safety Data Sheets (MSDS), Indoor Air Quality(IAQ) test data, product warranties, source material characteristics, recycled content data,environmental statements, and durability information. In addition, this step may involveresearching other environmental issues, building codes, government regulations, buildingindustry articles, model green building product specifications, and other sources of productdata. Research helps identify the full range of the projects building material options.
2. Evaluation. This step involves confirmation of the technical information, as well as filling ininformation gaps. For example, the evaluator may request product certifications frommanufacturers to help sort out possible exaggerated environmental product claims. Evaluationand assessment is relatively simple when comparing similar types of building materials usingthe environmental criteria. For example, a recycled content assessment between variousmanufacturers of medium density fiberboard is a relatively straightforward "apples to apples"comparison. However, the evaluation process is more complex when comparing differentproducts with the same function. Then it may become necessary to process both descriptiveand quantitative forms of data.
3. A life cycle assessment (LCA) is an evaluation of the relative "greenness" of buildingmaterials and products. LCA addresses the impacts of a product through all of its life stages.Although rather simple in principle, this approach has been difficult and expensive in actualpractice (although that appears to be changing).One tool that uses the LCA methodology isBEES (Building for Environmental and Economic Sustainability) software. It allows users tobalance the environmental and economic performance of building products
3. Selection. This step often involves the use of an evaluation matrix for scoring the project-specific environmental criteria. The total score of each product evaluation will indicate theproduct with the highest environmental attributes. Individual criteria included in the ratingsystem can be weighted to accommodate project-specific goals and objectives.
Source: http://www.calrecycle.ca.gov/Gree nBuilding/materials/
Natural buildings materialsNatural Building includes a varie ty of building techniques that focus on creating sustainable buildingswhich minimize their negative ecological impact. Natural Buildings often rely on non-industrial,minimally processed, locally av ailable, and renewable materials and can also utilize recycled orsalvaged materials.
Natural building materialsThere are as many Natural Buil ding technologies in the world as there are climates and bioregionsappropriate materials and tec hnique are largely dictated by the climate a nd available naturalresources of the place the building will stand. Most rely on a hand full of elem ental materials: earth(clay), wood, stone, sand, and straw (where straw can be loosely defined to include any dried non-woody plant material such as palm fronds, reeds, etc.). Based on the climate the building must coexistwith, these materials can be com bined in any number of ways to produce a natur al structure.
Strawbale construction uses bales of straw (com monly wheat, rice, rye and oats straw) as structuural
elements, building insulation, or both. a sustainable method for building-materials and energy needed for heatin g and cooling Renewable ,cost, easy a vailability, naturally fire-retardant and high insulation value Disadvantages include susceptibility to rot, difficulty of obtaining insuran ce coverage, and
high space requirementss for the straw itself
thickness of a straw bale, roughly 450 mm wide (or 18 inches) The mass of the straw and stucco/plaster coatings takes hours to warm up or cool down. This tempering effect of high mass walls can lead to additional energy savings when the
outside temperatures are variable, such as in spring and fall. Light houses may have to heat through the night or in the morning, to take the chill off until
the sun warms up the outside. A house, such as straw bale, with a high thermal mass will often maintain comfortable
temperatures without requiring this sporadic heating. Straw offers the perfect material for environmentally friendly construction due to its renewable
nature. The crop used for the straw can be grown locally, helping the local economy, and because it
absorbs carbon dioxide as it grows, buildings made from it can be seen as having zero, or even a negative carbon footprint.
Also, due to its high insulating properties, houses made of straw bales need almost noconventional heating, keeping running costs low and minimising environmental impact.
one ear / two ear /beveled / flute mo uth / fish mouth
Cork as a building material