Low Cost Green Building Materials selection Presented By Chirag Sanghvi CP-1911
Contents • Define Green Building Materials • Advantages Of Green Materials • Rating System Of Materials • Economic Benefits • Selection criteria For Green materials • Classification Of Materials Green Building Materials
WHAT IS GREEN BUILDING MATERIAL? • A material can be considered “GREEN” if:- • It is made up of renewable materials. • It has minimum possible environmental cost. • It has low energy utilization in its manufacturing as well as its functioning. • It is easily recyclable. • It is efficient in the long run.
Why Green Materials? • Current construction practices consume over 3 billion tons of raw materials per year. • Increased need to conserve non-renewable resources. • Reduce environmental impact of building and construction activities. • National, State, and Local Funding Opportunities
Advantages of Green Materials • Improved Energy Conservation • Improved indoor environment • Air Quality • Occupant Health • Reduced operations cost • Lower environmental Impact Green Building Materials Green Building Materials 5
Selection Criteria • Resource Efficiency • Recycled content • Renewable • Efficient manufacturing process • Local availability • Easily recyclable • Recyclable Packaging • Product Durability • Energy Conservation • Water Conservation Green Building Materials Green Building Materials 6
Selection Criteria- con’t • Indoor Environmental Quality • Moisture resistant • Minimal Emissions (VOC) • Installation has low (VOC) • Healthy cleaning or maintenance • Cost Efficient • Installation • Maintenance • Within specifications of project budget Green Building Materials Green Building Materials 7
How are materials rated? • U.S. Green Building Council • Non-profit organization committed to expanding sustainable building practices • LEED- Leadership in Energy & Environmental Design • Developed rating systems for construction projects in 2000 • Voluntary consensus based standards • Design and Construction Practices meeting specified standards reducing negative impacts on occupants and environment • Project Certification Process using appropriate comprehensive rating system, projects earn credits by meeting technical requirements Green Building Materials Green Building Materials 8
Economic benefits • The economic benefits of green buildings should be understood from the point of view of operation of the building and the resultant savings in its lifetime. • At the construction stage, monetary savings can result from choice of building materials The First CostsSavings = costs and savings from incorporating green features into a building • Life-Cycle Costs/Savings = costs/savings over a building’s or feature’s useful life • The first cost of the green buildings vary significantly depending on specific project goals. While there are many significant benefits that are ‘no additional cost’ (like no west facing openings) , some features will cost more in both design and material cost.
A design approach of using appropriate building systems may result in actual lowering of first costs by as much as 20%. In comparison estimates for additional first cost of mainstream green buildings are as low as 0-3%, for LEED Certified, to 10% or more for higher LEED ratings • It is estimated that the design and building of a commercial building constitutes just 2% of the overall cost in 30 years. The rest of the 98% comprises of operations, maintenance, finance and employee costs. Green Building Materials
SELECTION CRITERIA FOR GREEN MATERIAL • Local availability of materials. • Embodied energy of materials. • % of recycled/waste materials used. • Rapidly renewable materials. • Contribution in energy efficiency of building. • Recyclability of materials. • Durability • Environmental Impact
Local availability of materials • As far as possible locally available materials are to be preferred so as to minimize the energy spent in transportation of the building materials. Energy consumed in transportation should be considered as total energy spent on transporting materials starting from the place of manufacturing.
Rating Criteria for Availability of materials, near the site( 2points) • Supplier between 0-5 km: 2 points • Supplier between 5-10 km: 1.8 points • Supplier between 10-20 km: 1.5 points • Supplier between 20-30 km: 1.3 points • Supplier between 30-50 km: 1 point • Supplier between 50-75 km: 0.8 points • Supplier between 75-100 km: 0.6 points • Supplier between 100-250 km: 0.4 points • Supplier between 250-1000 km: 0.2 points • Supplier at a distance greater than 1000 km: 0 points
Embodied energy of materials • Embodied energy is an assessment of the energy required to manufacture any building material. This include energy required to extract raw materials from nature, energy used to transport raw materials to manufacturing unit and the energy used in manufacturing activities to provide a finished product.
Rating Criteria for the Embodied energy of Materials ( 2 points) • Benchmark Value: 5MJ/Kg • Available Points on Benchmark: 1 • Embodied Energy between Benchmark to -10%: 1.2 Points • Embodied Energy between -10% to -25% of Benchmark: 1.3 Points • Embodied Energy between -25% to -50% of Benchmark: 1.4 Points • Embodied Energy between -50% to -75% of Benchmark: 1.6 Points • Embodied Energy between -75% to -100% of Benchmark: 2.0 Points • Embodied Energy between Benchmark to 25% of Benchmark: 0.9 Points • Embodied Energy between 25% to 50% of Benchmark: 0.8 Points • Embodied Energy between 50% to 75% of Benchmark: 0.7 Points • Embodied Energy between 75% to 100% of Benchmark: 0.5 Points • Embodied Energy between 100% to 200% of Benchmark: 0.4 Points • Embodied Energy between 200% to 300% of Benchmark: 0.3 Points • Embodied Energy between 300% to 400% of Benchmark: 0.1 Points • Embodied Energy Above 400% of Benchmark: 0 Points
Percentage of recycled/waste materials used • Building materials can be manufactured using recycled materials or using waste materials. Use of recycled materials helps the environment and the economy in several ways. A significant effect is that of lessening the need for manufacture with virgin, non-renewable resources, which saves precious resources, energy and cost.
Percentage of Recycled materials (1 point): • If a material rather than using new materials uses up recycled materials then it qualifies as a potential green material. For e.g.- If A and B are two wastes or two recycled materials and if material C is made up of material A and B in some proportion than material C qualifies to obtain points under this criteria. • The percentage of recycled material can be worked out as follows: Calculate the amount of such materials in 1m3 of new material and find out its proportion in m3. Then divide the two and you can establish how much percentage of recycled materials is contained in a new material. • The no of points awarded are found by the following formula: • No of Points= (% of Recyclable materials)/100
Use of renewable materials • Materials manufactured or materials with resources that are renewable (i.e. wood or solar power) rather than non-renewable (i.e. fossil fuels) shall be preferred.
Rapidly Renewable Materials ( 1 point): • If the material has the capability of being renewed in a short period of time then the material is termed as a Rapidly Renewable material and is liable to get extra points as a green material. • If the material is renewed in a cycle of 10 years or shorter then it can be termed as a good rapidly renewable material and it gets 1 point in the scale. • If the material has a higher period of renew ability then it gets points relative to its period, i.e. If it is 11 years then points obtained are 0.9 and if 12 years then 0.8 and so on up to 19 years. • For a period of 20 or more years no points are awarded and the material is termed as a normal renewable material.
Contribution in Energy Efficiency of buildings • Construction and operation of buildings utilizing major portion of total energy produced. With little careful efforts, designers and builders can reduce energy loads on structures, reducing energy requirements and the strain on natural resources. With proper orientation of building with reference to solar radiation to receive maximum day lighting, operable windows for natural cross-ventilation, use of passive cooling techniques, (eliminating or lessening the need for air conditioning), walling unit with lower U values, roof insulation, water-saving devices and more efficient appliances can all work to lessen energy needs. Consideration of alternate energy source use, such as wind, solar and tidal power, can help alleviate reliance on traditional fossil fuel sources.
Energy Efficiency (1 point): • Energy Efficiency can be judged on the basis of U-value of the material. After studying U-values of various materials and studying their effects we found that for the value of 2.31 W/m-K no effect on interior temperature is caused due to exterior temperature. So a Benchmark U-value is adopted as 2.31 W/m-K. • So if a material is having a U-value lower than this then it can get a maximum of 1 point and if it is higher than the benchmark then it does not get any points in this criteria.
Recyclability of materials • The recyclability of the materials can be judged from quantity of materials recovered for re-use after the useful life of materials/products or after demolition of the building.
Criteria for the Recyclability of Materials (3 points) • If the material is recyclable >90% then 3 points • If the material is recyclable >80% and <90% then 2.5 points • If the material is recyclable >60% and <80% then 2 points • If the material is recyclable >40% and <60% then 1.5 points • If the material is recyclable >20% and <40% then 1 points • If the material is recyclable >0% and <20% then 0 points 0 marks are given to materials from 0 to 20%. It may happen that most of the times that the cost of recycling is less than the cost of the new materials but if it is vice versa than the recycling of the material has no meaning.
Durability • Materials which are long lasting and needing little maintenance are preferred. Material replacement puts a strain on the earth, its resources and inhabitants. In making materials more durable and easy to maintain, manufacturers can help in eliminating a costly, damaging and time-consuming process of replacement.
Durability Criteria(1 point): • Material life is greater than 80 years: 1 point • Material life between 60-80 years: 0.8 points • Material life between 40-60 years: 0.6 points • Material life between 20-40 years: 0.4 points • Material life between 5-20 years: 0.3 points • Material life between 1-5 years: 0.2 points • Material life less than 1 year: 0.1 points
Environmental Impact • All materials used for construction of buildings must not harm the environment, pollute air or water, or cause damage to the earth, its inhabitants and its ecosystems during manufacturing process, and also during use or disposal after end of life. Material should be non-toxic and contribute to good indoor air quality.
Environmental Impact( +0.5 to -2 points): Disposal conditions of a material can be classified into four and points are allocated on that basis. The conditions are as follows: • If the material is degraded by itself and may or may not be useful for alternate usage but in now way produces any harmful materials then it gets 0.5 points. • If the material only occupies land but in no way produces any harmful or hazardous waste then it gets 0 points. (Non-Biodegradable) • If the material pollutes the land and degrades the soil quality then the material gets -1 point. • If the material produces Hazardous or toxic materials after disposal or a toxic leachate (such that it pollutes the Ground Water Table) then the material will get -2 points. • If during incineration it produces carcinogens like Dioxin or Furans then the material is outright rejected as green material.
Classification of materials • Structural/Partition Material • Ventilation/Thermal Insulation • Finishing Materials/Paints • Materials for furniture
Structural/Partition materials • Mud Brick The production of simple earth blocks only requires around one thousand of the energy needed to fire bricks, and even in cases where earth is stabilized with cement it is no more than a sixth per kg of material.
Fly ash brick In India alone, approximately 100 million tones are generated per year. The construction technique and process is improved as the material allows for lighter structures, shallower foundations, less expensive transport costs with environmental benefits as fewer emissions are produced and the speed of setting is quicker for comparative standard bricks, and less usage of cement and steel reinforcement.
Claytech Claytech bricks are comprised of clay, sand and straw. As they are hand pressed and unfired, they are unsuitable for load bearing walls. Benefits do include good acoustic properties, thermal qualities that help regulate temperature and humidity, the clay absorbs and diffuses water vapor, absorbs odors and have a low embodied energy.
Ventilation/Thermal insulation materials • Flax Insulation Flax is a plant native to the region extending from the eastern Mediterranean to India and China. Natural insulation can be made from 100% flax fibers by matting them together into a non-woven process and then utilizing their properties for insulation in lofts or wall cavities. The material has very low embodied energy and the thermal conductivity of flax insulation is 0.037 W/mK, making it ideal for breathable constructions.
Straw and Resin Panels Using agricultural waste, such as straw, a binder is applied that is made up of local resins to form insulating panels that can be easily installed under and between existing corrugated metal sheeting – and lightweight corrugated iron used as roofing.
Bamboo Screens The use of bamboo as a building material like sunshades is seen in many places.The big value of bamboo screens is the fact that it is open to daylight and air. So the gap between screen and window is very well ventilated. The rays of sunlight entering through the screens look nice but don’t result in overheating of the house.
Fenestration and glazing systems • Fenestration is provided for the purposes of heat gain, daylighting and ventilation. Their pattern and configuration form an important aspect of building design and its energy requirement. Appropriate design of openings and shading devices helps to minimize the effects of sun and wind or allow them into a building. Ventilation lets fresh air in and hot air out, resulting in cooling. • Glazing is generally transparent to solar radiation but opaque to long wave radiation. This characteristic can be used to heat a buildings interior by promoting heat gain. This is desirable in winter, but may cause overheating in summer. This overheating through large aesthetic-driven areas of exposed glass is commonly observed in commercial buildings in India today and in turn results in excessive loads on air conditioning systems. For reducing solar gain during summer, window size should be kept minimum in the hot and dry regions. • For example, in Ahmadabad, the number of uncomfortable hours in a year can be reduced by as much as 35% if glazing is taken as 10% of the floor area instead of, say, 20%.
Fig 2.14 Transmission properties of reflecting glass (6mm thick). • The amount of light entering a building needs to be effectively controlled to maintain a suitable level of comfort. This can be achieved through proprietary systems such as openable shutters and movable covers like curtains or Venetian blinds. Tinted glazing with surface coatings can also be used to control solar transmission, absorption and reflection. Surface coatings can reduce the transmission of solar radiation through a piece of 6mm thick absorbing glass by about 45%. Reflective glass is usually achieved by a layer of reflective material or a low emittance layer. Glazing of these types can reduce heat gain without obstructing views from the building. They are usually used for windows which cannot be shaded externally.
Finishing materials/paints • Tire Veneer In the retreading process, the old tread is removed by grinding and the resulting dust is termed buffings. These buffings are non-laminated polymerically bound black SBR rubber. Areas of use extend to areas such as sports and recreation, animal housing and high traffic areas outdoors – and a variety of consumer products, vibration dampeners and furniture surfaces internally.
Eco Paint Ecopaint is a new paint has been developed, to act as a sponge for some of the most noxious gases (NOx) released in vehicle exhaust that can lead to respiratory problems and triggers smog. The paint’s base is polysiloxane, a silicon-based polymer.Embedded are 30 nanometre wide spherical nanoparticles of titanium dioxide and calcium carbonate – being so small makes it possible for the paint to appear clear, with the possibility to add pigment for desired effects.
Durat Durat is a solid polyester based material used for custom made interior surfaces and molds. The content includes recycled plastics and is itself 100% recyclable. The product is very durable, resistant to wear, humidity, chemicals and can be renewed by slight sanding. The material is manufactured in sheets typically, but can create sink models and custom made sanitary units.
Materials for furniture • Coir – CNSL Board • The Coir-CNSL Board is a wood alternative which can be used for surfacing, door and window shutters, partitioning, false ceiling, panelling, furniture, cabinets, packaging, etc. Both the starting materials i.e. coconut fibre and cashew nut shell liquid are available substantially in coastal areas and are renewable agro-wastes. Its 30% cheaper then commercially available alternatives.
Dakota Burl Dakota Burl composite is a unique bio-based material, which exhibits the same aesthetic qualities of traditional burled woods. The material is created from an agricultural fiber and sunflower hulls. The material is primarily for interior use, such as tables and counters, cabinetry, furniture and similar architectural applications.
Palm Fiberboard Palm trees are dense throughout most tropical and subtropical regions. Stripped palm stalks, palm leaves and the tree trunk are made waste in vast quantities after harvesting oil takes place. Optimizing various stages of the process for pulping the fibers they may be made into Fiberboards. They are used in furniture industry.