Sustainable building products are firmly establishing their way into construction and infrastructure, BY TEAM MT
The key words here are responsible care. Elaborate that with equally important words such as conservation of energy, research, development and innovation and you get a clear picture of what constitutes green building materials.
One of the reasons why the entire industry, be it real estate, infrastructure or manufacturing is enamoured of all things green is the growing fear of climate change. Thus green building has become the rage.
Thanik B, director, business development & strategy, eco-buildings business, Schneider Electric India, said, “We meet the consultant, architect and the end customer and understand their expectations of energy conservation, safety and scalability. Our experts then propose a best solution from our range of products. While bringing together technologies and engineering practices to design a solution, we also chalk out our strategy to execute the opportunity to meet the desired timelines. Our solution, Struxureware, for building operation is not just a product — it’s a complete package of software, hardware, installation, engineering & service packages which helps our customer to make the most of their facilities while using optimum energy.”
The foundation of any construction project is rooted in the concept and design stages. The concept stage has the largest impact on cost and performance. In designing environmentally optimal buildings, the objective is to minimise the total environmental impact associated with all life-cycle stages of the building project. Gautam Ahuja, managing director, Ahuja Constructions says, “After a detailed analysis by architects, MEP, project managers and other consultants, a total of 42 credits have been successfully applied for under the IGBC LEED India CS. This includes energy modelling, indoor environment and quality, site orientation, water efficiency, innovation design, etc.”
All kinds of green ideas are spreading in the housing market. But what in the world is green building? The bifurcating supply chains of untold building materials and components, let alone entire houses, are beyond the grip of consumers. Often, most of the materials lack uniform standards, as well as credible institutions providing and maintaining them, and it is not uncommon to find suppliers offer everything under the sun as green. Their incentive is plain enough: in a troubled housing market, which threatens to collapse on account of the credit crunch, greenery sells better than ever.
Ahuja lists out a few things that developers need to keep in mind when constructing green buildings. “We stress on sub-metering of different locations to assess energy consumption during operational stage, the study of heat island effect, CFD analysis for air conditioning, efficient usage of water for landscaping and air conditioning, monitoring of construction waste at the initial stages, solar panels to provide heated water in the common areas, green walls for indoor and outdoor locations, LOW-E DGU laminated glass, recyclable materials for construction comprising 15% of construction cost, low VOC paints, FEC certified wood, car charging ports in car parking spaces and STP for recycling waste water.”
As a prerequisite, the development company designates 50% area for landscape as well. Besides this, rigid control parameters have been placed on the contractors, MEP consultants & project managers to follow international standards for green building, thus making sure that the consultants contribute more to make a true green building.
Mehernosh N. Pithawala, head, construction materials, Godrej Construction, says, “TUFFBLOCKS AAC is one of the most lightweight materials used in construction. It has a density of 650 kg/m3 making it lighter than water and approximately one third the weight of clay bricks. This results in substantial reduction in the dead load of buildings which in turn leads to savings in steel and cement – the two most energy intensive materials. It is estimated that the reduction in steel reinforcement can be as high as 30%.”
TUFFBLOCKS AAC is not just a green product but also a cost effective one. Its lightweight contributes in cost savings even during the construction stage. Therefore, it is of essence that a developer is approached at the conceptualization stage so that the product is incorporated in the project since the very beginning. This helps the structural consultant to reduce the loading on the structure and enables substantial savings in steel reinforcement.
Green building design is based on form-follows-function which is associated with modernist architecture. This principle rests on the concept that the shape of a building should be primarily based upon its intended function or purpose. This, however, should not be mistaken as a compromise in the aesthetic appeal of the design. In fact, buildings all around the world are being built with its functionality and sustainability in mind without losing out on its visual appeal. Therefore, the focus is on building something that is functional, aesthetic and sustainable at the same time. Rumi Engineer, head of green building consulting & energy conservation at Godrej & Boyce Manufacturing Company says, “Passive cooling techniques should be incorporated in the building design if it needs to be truly called a green building. Passive cooling is a form of building design that involves preventive and natural heat dissipation techniques for improving indoor thermal comfort at low or nil energy costs. Preventive techniques include orientation of the building facade along the north south direction, thermal insulation of the building envelope and optimal design of shading devices. Natural cooling could be achieved by way of cross ventilation and evaporative cooling techniques.”
Thermal insulation for building envelope, which consists of roof, fenestration, glazing and the exterior walls, is the most important aspect of a green building project. A thermally insulated building envelope involves using materials that reduce heat transfer by conduction, radiation and convection. It helps cut down the heat load in the building, downsizing the air conditioning equipment required to cool the spaces and hence, results in lowering of the capital costs for the project. “Thermal performance of fenestration, glazing, wall and roof assembly depends on solar heat gain coefficient (SHGC) and solar energy transmittance measured by U-value. Lower the SHGC and U values better are the thermal insulation properties of the wall, roof, fenestration and glass,” adds Engineer.
While there are several companies manufacturing green building products, Wienerberger India makes clay bricks called Porotherm. Made from natural clay, Porotherm evens out temperature variations through thermal capacity effects, to protect against cold in winter and ensure a comfortable and healthy room in summer.
Fly-ash bricks are also increasingly gaining acceptance in construction. These bricks are fire and moisture resistant, while being eco-friendly and aesthetically appealing. Manoj Kumar, managing director at Hess India, says, “Converting fly-ash into construction material is economical and the bricks are much cheaper. It enables considerable cost savings on plastering mortar. Considering all the talks around sustainability, the fly-ash bricks are ideal exponents of sustainability.”
In terms of infrastructure, concessionaires are increasingly looking at plastic bricks. According to a spokesperson of a company, plastic bricks have found their way in highway and railway infrastructure. Plastic from the millions of the bottles and bags are melted and moulded in the form of bricks in the construction of roads. This has considerably enhanced the elastic nature of the surface helping in more load-bearing capacity of highways. In India, this technology has been initiated on an experimental basis for railway sleepers, but was stopped since the danger to fire is a major concern.
Green building materials are composed of renewable, rather than non-renewable resources. These materials are environment-friendly and offer specific benefits including 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, and so on.