Green building design keeps check on full life cycle impacts of the resources that make up the structure. Bio Climatic Design takes into account local climate and environmental conditions to help achieve thermal and visual comfort inside and make the best possible use of solar or wind energy.
-Focus is on renewable resources right from the beginning
-Use of sunlight through solar panels and photovoltaic cells
-Using green roofs and rain gardens to reduce rainwater run-off
-Using packed gravel instead of asphalt or concrete to enhance replenishment of
ground water
-Use high-efficiency windows and insulation in walls, ceilings, and floors
-Use trees in front of windows to produce shade in the summer and maximize solar rays during winter
Integrating Embodied Carbon Feedback in Early-Stage Design
It is impractical to reduce the Embodied Carbon of a building
once it is built, so strategize and optimize during the design and construction phases.
-Opportunities and Risks of Material Innovation in a Developing Construction Industry
-To ensure low embodied carbon, build with local, sustainable materials
-Rethinking Building Elements: Large-Scale Additive Manufacturing
-A Brave New Hub for Building Material Reuse
-When a building reaches the end of its life, many building materials can be recycled, remaining others be directly reused in new projects, achieving maximum reduction in embodied carbon.
Guidelines for reducing Embodied Energy
-Lightweight building construction such as timber frame is usually lower in Embodied Energy than heavyweight construction, where a lightweight building is the most appropriate and may result in the lowest life cycle energy use, e.g. hot, humid climates; sloping or shaded sites; sensitive landscapes.
-In climates with greater heating and cooling requirements and significant day–night temperature variations, embodied energy in a high level of well-insulated thermal mass can significantly offset the energy used for heating and cooling.
-There is little benefit in building a house with high embodied energy in the thermal mass or other elements of the envelope in areas where heating and cooling requirements are minimal or where other passive design principles are not applied.
-Each design should select the best combination the application based on climate, transport distances, availability of materials and budget, balanced against known embodied energy content.
Design for Long Life and Adaptability, Uusing Durable Low Maintenance Materials
-Ensure materials can be easily separated.
-Avoid bigger building than needed, and save materials.
-Modify or refurbish instead of demolishing or adding.
-Ensure construction wastes and materials from demolition of existing buildings are reused
or recycled.
-Use locally sourced materials (including materials salvaged on site) to reduce transport.
-Select low embodied energy materials (which may include materials with a high recycled content), preferably based on supplier-specific data.
-Avoid wasteful material use- specify standard sizes wherever possible windows, door and panels to avoid using additional materials as fillers. Minimise energy intensive finishes, such as paints.
-Ensure offcuts are recycled and use only sufficient structural materials to ensure stability. And meet construction standards.
-Select materials that can be reused or recycled.
-Give preference to materials, manufactured using renewable energy sources.
-Use efficient building envelope design and fittings to minimise materials, an energy efficient building envelope can downsize or eliminate the need for heaters and coolers, water-efficient taps can allow downsizing of water pipes.
-Get information from the suppliers about their products and share this information.
Green Construction – Material Selection
Green Building Materials
Selecting what materials to use is usually part of the designing stage as well to ensure sustainability in the following years, such as:
-Rapidly renewable plant materials like bamboo and straw
-Lumber from forests certified to be sustainably managed
-Dimension stone, a natural stone or rock that has been selected and fabricated
-Recycled stone and metal and other products that are non-toxic, reusable, renewable, and/or recyclable
-Use building materials from local sources to minimize energy use due to their transportation.
-Along with materials, sustainability in the construction process can also include acts such as employing local, so that opportunities and greater well-being are fostered in the local community.
Sustainable Building Materials
-Reclaimed wood, reclaimed metal
-Precast concrete
-Bamboo
-Cork
-Shipping container…
-Rammed-earth tires
-Earth bag
-Recycled steel
-Ferrock
-Timber Crete, Grass Crete, Paper Crete, Hemp Crete
-Sheep’s wool
-Plant based Polyurethane Rigid Foam
-Straw cable
-Recycled plastic
Ferrock – Alternative to Cement from Waste
-Approximately 95 per cent of Ferrock is made from recycled materials such as waste steel dust and silica from the ground
up glass.
-The steel dust, upon reaction with Carbon Dioxide (CO2), produces iron carbonate, which when solidifies turns into solid-rock known as Ferrock.
-One of the unique qualities of Ferrock is that it absorbs more CO2, (a highly toxic gas) than it creates, unlike cement.
-Ferrock is five times stronger than the typical Portland cement.
Timber Crete: A blend of sawmill waste, cement, sand, binders and a non-toxic deflocculating additive, which is cured using the renewable resources of sun and wind into a unique building block.
Glass-Crete: Glass-Crete specially designed for the toughest construction clean-up projects, removes concrete, mortar and other cement-type materials from architectural tempered and plate glass surfaces.
Plastic Wastes are Ideal Building Materials
-Plastics are strong, durable, waterproof, lightweight, easy to mould, and recyclable.
-All polymers are, technologically, 100% recyclable. Some of them have the perfect cradle-to-cradle lifecycle: they can be used again and again to produce the same goods.
-Some plastics can be reused just as they are by shredding an object into flakes, melting it, and reusing. Such recycled plastics may have lower mechanical properties compared to virgin plastics, because each time you melt and process a plastic, the polymeric chains degrade. But these properties can be recovered by mixing it to additives or virgin plastic.
-Examples of successful industrial recycling include PET, or poly (ethylene terephthalate), which is used to make soft drinks bottles, and polystyrene.
Waste Reduction or Recycling
Waste can be reduced on several levels by taking a green approach. In terms of construction, using the materials listed earlier helps divert waste from landfills. With the appropriate green-building measures, waste reduction carries on to the operation of a building as well. Waste Recycling, including Waste Water Recycling is an area where the scope for conservation is quiet high.
-On site waste management, such as separating garbage, recycling and compost
-Centralized wastewater treatment systems for reusing wastewater from dishwashing or washing machines
-However, these are costly and use a lot of energy – there are many smaller steps to be taken as an alternative, such as low power showerheads, converting wastewater to fertilizer via a biogas plant, and more, making it easy for occupants to reduce energy waste as a part of their daily routines, such as intelligent building design to allow them enough light that daytime lights are unnecessary, to mention one option.
Rain Water Harvesting
-Rainwater from the roof and rear terrace is filtered and let into the well to replenish the underground water table, this water is also treated.
-Turbidity is removed with pressure sand filter. Iron is removed with an iron removal filter. Odour, however, is taken care of by an activated carbon filter.
-In many cities, the public water supply cannot always be trusted. So, we need other sources.
Maintenance of Green Buildings
Maintaining a building is important to ensure it remains sustainable and profitable.
-As the building ages, it is important to check areas of the building to make sure they are still at an acceptable quality level.
-Low maintenance costs, taking into account the increased usage of natural light and temperature control services, the more natural used, less dependency on air conditioners, and lighting systems.
-Smaller scale maintenance, such as cleaning the building, improving indoor air quality, reducing water pollution, and maintaining environmentally sustainable concepts.
Operational Cost of a Green Building
Lower energy costs from some of the design aspects such as:
-High efficiency windows and insulation
-‘Cool Roofs’ that create high solar reflectance, reducing heat transfer to the building, and high thermal remittance, when a large percentage of absorbed/non-reflected solar energy is able to be released.
-These designs/efficient materials reduce costs directly in maximizing natural light, heating and cooling, thereby requiring less electricity usage.
-Capitalized natural ventilation
-Heat recovery ventilation systems to recover heat from used air and transfer it to fresh air
-Install fluorescent / LED to use 2/3 to 3/4 less energy than incandescent bulbs, lowering electricity use directly/ indirectly with cooling loads
-Installing highly efficient appliances, Low flow toilets reduce energy directly by their efficiency and producing less waste heat.
Heath Benefits
Health benefits from green building are greater than just a better natural feeling.
-Indoor air pollution lies among top five environmental risks. Unhealthy air is found in up to 30% of new and renovated buildings.
-W.H.O. reports that indoor air pollution causes 14 times more deaths than outdoor air pollution (2.8 million lives) of hundreds of EPA-regulated chemicals,
only ozone and sulphur dioxide are more prevalent outdoor
than indoors.
-Most of our dwellings have too much lead dust or chippings, causes of kidney and red blood cell damage impairs mental and physical development, may increase high blood pressure.
-About a quarter of the nation’s largest industrial plants and water treatment facilities are in serious violation of pollution standards at any one time.
-These risks can be reduced and conditions improved by following green building concepts in regulating natural air ventilation and quality non-toxic, natural and renewable materials.
– ASHRAE 90.1 provides significant guidance, while IGBC (Indian Green Building Council) and the NECB (National Energy Code for Buildings) are other valuable resources.
Green Building Certificaiton
Building owners have the option of Green upgradation with Green Certification/ Rating Systems such as:
-BEE Star Ratings for buildings
-GRIHA
-IGBC and USGBC based-LEED certifications.
-All of these use Energy Conservation Building Code (ECBC) 2017 as the baseline requirement to evaluate energy consumption of building.
(To be continued to the next issue)
G Harihara Iyer
The author is a Fellow of the Institution of Engineers, a Certified Energy Auditor and a Lead Auditor for Energy Management System ISO 50001. He is also a Graduate Member of the All India Management Association, a Life Member of the Mining Engineer’s Association
of India and a Life Member of the Orissa Engineering Congress.
