Schneider

Feature

Green Building Blocks

July 2011
A well-populated market for green building products is spurring the green building movement in the country.

The Indian Green Building Council (IGBC) defines a green building as "one that uses less water, optimises energy efficiency, conserves natural resources, generates less waste and provides healthier spaces for occupants, compared to a conventional building." These aims are achieved by combining sustainable design, green construction methods and materials made of renewable resources and operations. Green materials help reduce the environmental impact associated with the extraction, transport, processing, fabrication, installation, reuse, recycling and disposal of building materials.

Without locally available green building materials, the construction of green buildings would become practically difficult and commercially unviable. "Since the CII pioneered the green building movement in 2001, the number of green materials in the market has increased manifold. Today, designers and developers can choose from multiple suppliers for most products," says Srinivas S, Principal Counsellor, LEED & IGBC Accredited Professional, Confederation of Indian Industry, CII-Godrej GBC (IGBC).

Selecting green

Fly-ash blocks, roof and wall insulatoin, high-performance glass, green paints, water-efficient fixtures, indoor air monitoring devices, rainwater harvesting, high-efficiency chillers, recycled steel, aluminium and bamboo-based products are a few essentials of green construction, selected for their resource efficiency, indoor air quality, energy efficiency, water conservation and affordability. According to Srinivas, "All the factors need not be equally weighed during selection. Each is treated separately in terms of the impact it is likely to create. For instance, the impact of installing a rainwater system is different from having a car pool."

It would seem that these criteria are not at odds with each other, but sometimes they may be. Carpets, for example, provide insulation against extreme temperatures (and sound) and thus help conserve energy. But, traditional carpets release harmful volatile organic compounds (VOCs) from adhesives used to glue them to the floor and chemicals used during manufacture to make them stain-, flame- and soil-resistant; VOCs lower air quality. Still, smart developers are opting for recycled carpets or cheaper and easier to maintain carpet tiles that emit less VOC and score better on resource efficiency, indoor air quality and affordability. Besides other low-emitting materials like paints and composite woods, the Gold LEED-certified Grundfos Pumps India Pvt Ltd building in Chennai uses low VOC sealants and carpets.

Evaluating products

When selecting products, developers should take into account technical specifications such as indoor air quality, test data, warranties and certifications, and source materials. A lifecycle assessment (LCA) that looks at a product's impact over its lifetime also helps evaluate the 'greenness' of building materials. BEES (Building for Environmental and Economic Sustainability) software, for example, is an evaluation tool developed by the USA's National Institute of Standards and Technology's Building and Fire Research Laboratory, which can be down-loaded at the BEES wesbite. Srinivas believes that Indian developers stand to benefit from such tools, which the country still lacks. Even so, the IGBC helps the Indian building community by making the results of such analysis readily available.

The Paharpur Business Centre, a retrofit, green-certified building, selects Green Seal products certified by the US Green Building Council's Green Seal Environmental Leadership Standards within its Leadership in Energy and Environmental Design (LEED) rating systems. For instance, its housekeeping department uses VOC-free products. "Our in-house research team analyses in detail the pollutant level in each green product purchased," shares CEO Kamal Meattle. "Also, we purchase only BEE 5 Star labelled electronic equipment."

Payback period and allocation as a percentage of overall budget must also be considered. According to Meattle, "Payback periods vary and are a function of the cost, energy efficiency and scale of usage. For instance, when the Paharpur Business Centre switched over from conventional lighting to CFLs, the investment was returned in less than three years. But, the payback period of investing in cooling towers for the centre's air-conditioning system was more than eight years."

Glass and glazing

Glass façades of buildings in cities across the country testify that glazing is becoming a preferred building material. Considering the tropical Indian climate, however, and consequent load on air-conditioning where glass is used as a predominant construction material, developers need to focus on its characteristics. The selection of glazing can impact eight points under the LEED rating system.

Characteristics in question include the U-value of glass denoting the rate of heat flow owing to conduction; the shading coefficient showing the extent of direct solar heat gain; the relative heat gain (RHG) denoting the combined effect of the shading coefficient and U-value; the visual light transmittance (VLT) that indicates the percentage of the visible portion of the solar spectrum transmitted through the glass and acoustic performance. High-performance glazing is associated with U-values of 1.7 to 3.0 W/sq m deg K, shading coefficient of 0.1 to 0.4 W/sq m deg K and VLT ranging between 40 and 60 per cent.

The USGBC-certified, Platinum-rated ITC Green Centre uses no artificial light during the day thanks to its design features and specially designed glazing. Architect Rahul Kumar of Rajender Kumar and Associates turned to Saint-Gobain to come up with the best-suited sustainable glazing. He chose Saint-Gobain's Cool-lite Blue Green, double glazed with Ekologik, and Parsol Green, double glazed with Ekologik. While a normal, 170,000 sq ft building would consume 35,00,000 kWh/year, the ITC Green Centre uses 20,00,000 kWh/year, thus saving about Rs 9 million in energy costs for an increase in the upfront investment of only 15 per cent. R Subramanian, Director - Sales and Marketing, Saint-Gobain Glass India, says, "Saint-Gobain's range of products help create 'greener' buildings by providing better daylighting, cutting down incoming solar heat and improving thermal insulation. Green building norms must be made an essential part of new buildings. It is equally important to renovate old buildings and the Government of India's ECBC (Energy Conservation Building Code) should be made mandatory as soon as possible."

Paints and coatings

Paint plays a key role in enhancing indoor aesthetics but releases harmful VOCs. Fortunately, companies like Jotun India and Berger Paints India have introduced green paints that enhance the productivity and well-being of occupants. Green buildings rated by the USGBC and IGBC for LEED certification are expected to use non-flat coatings with VOCs (in g/l of product minus water) up to 150 and flat coatings with VOC up to 50. "The majority of Jotun's solvent-based and water-based paints meet European VOC norms," shares Percy Jijina, General Manager, Decorative, Jotun India Pvt Ltd.

"Jotun is a founding member of the Emirates Green Building Council in the Middle East as well as a member of the IGBC. So, we aim to play a significant role in the green building movement in India. Fenomastic Gold, Fenomastic Silk, Jotashield Thermo and HB - all Jotun products in the Indian market - are LEED-certified and VOC-free." Berger Paints India Ltd has recently launched its flagship green brand 'Breathe Easy'. "Breathe Easy is washable and has no added heavy metals, has minimum aromatic content, low odour and acceptable VOC levels," adds Abhijit Roy, COO, Berger Paints. "Breathe Easy's oxyrich formula reduces carbon emission in the air to almost zero. It is certified eco-friendly and healthy by the Green Label Committee of Singapore's Environment & Health Safety Standards."

Coatings and special roofing materials also play a role in constructing green buildings. "Ackruti Gold has acquired the LEED India Core and Shell Platinum pre-certification," shares Hemant Shah, Chairman, Ackruti City Ltd. "Like our other projects, it implements technologies and systems for sustainable development. We have used high solar reflective index (SRI) materials on the roof and other areas to reduce the heat island effect. Some of these products are vegetative roof, china mosaic tiles and solar panel (photovoltaic)."

Energy and water savers

"Ackruti Gold lays stress on rainwater harvesting and storm water management systems for efficient water management," adds Shah. Paharpur Business Centre in Delhi is designed to harvest rainwater to recharge groundwater levels. Normal annual rainfall helps save 183,000 litre of water per annum. Water-saving drip irrigation systems, sensor taps and waterless urinals, along with the use of effluent water from the kitchen for gardening and the vermicompost pit are other initiatives. Plants are grown using hydroponics (on re-circulated water instead of soil).

Max Super Speciality Hospital in Patparganj (Delhi) is a LEED-certified, Gold-rated building spread over about 0.23 million sq ft. Mayank Kaushal Project Architect and Green Building Coordinator, says, "The hospital uses energy-efficient light fixtures that have helped reduce power consumed by over 18 per cent. The building maintains an LPD (Light Power Density) as low as 0.7 W/sq ft, which is low for a hospital. Despite that, the hospital maintains the lux levels required by the National Building Code. Power savings are achieved without sacrificing the lux level of such a critical environment."

Panels and partitions

Drywall construction techniques entailing the use of fibre cement boards in interiors as partitions, wall or ceiling claddings, or flooring substrates, and for exterior applications such as claddings, partitions, roof sarking, or as roof tile underlays, are gaining momentum.

"Everest's fibre cement boards comprise of 40 per cent recycled material - (flyash accounts for 35 per cent and recycled cement paper kraft for 5 per cent), and about 70 per cent of the material can be salvaged and reused," says Rakesh Verma, GM Boards, Domestic Sales, Everest Industries Ltd. "Being termite-, weather- and moisture-resistant, the boards also minimise maintenance needs, thus optimising the product's performance. Using these boards reduces the operating cost by 15 per cent and can earn up to four LEED points, by minimising energy needs, contributing to construction waste management, reusing resources, recycling content, being a lightweight regional building product and conserving water." Now available in wood finish, Everest fibre cement boards are an energy-efficient substitute for wood products.

"At the Gold-rated Delhi International Airport Terminal, Everest fibre cement board has been used as a sarking board, sandwiched between the metal roofing sheet, along with insulation and vapour barriers for an overall system sound insulation of 50 dB," adds Verma. "In addition to effective sound insulation, the boards, in combination with insulation panels, also compliment the overall thermal insulation of the system. Kalpataru Square, a Platinum-rated, LEED-certified project, uses these boards for its ceiling at the entrance to withstand wind pressure of 2.4 Kpa (suction) and uses Everest Rondo 51 mm deflection head, stud and Everest heavy duty board (6mm)."

Companies needing to depend on retrofits could use Saint-Gobain Gyproc's gypsum-based, green products. Such termite-and fire-resistant dry products can help score green points on account of their high insulating properties, low embodied energy, high recycled content and zero need for water curing vis-à-vis traditional bricks/blocks. According to Venkat Subramanian, MD, Saint-Gobain Gyproc India, "Drywalls offer superior performance and acoustic insulation than that offered by a brick wall at a lesser thickness, along with better space utilisation. Gypsum boards are versatile and well-suited for partitions instead of wood. For instance, the Gold-rated Delhi International Airport Terminal 3 makes use of Gyproc drywalls in corridors and partitions in the shopping area; the Gold-rated Tamil Nadu Assembly uses Gyproc drywalls as cabin partitions; and the Gold-rated Cognizant building in Chennai also uses Gyproc drywalls for corridors and cabin partitions."

With an ever-increasing palette of materials to choose from, green architects, designers and consultants are bound to keep bettering their last green endeavour, to the benefit of the country.

Green buildings in India

India has taken significant strides in the construction of green buildings since the CII began promoting the concept in 2001. We have progressed from a modest 20,000 sq ft of green built-up area to a green building footprint of 704.36 million sq ft. This compares well with even a nation like the US, which has 1,363.3 million sq ft of LEED-certified commercial space.

Green buildings offer owners and occupants significant benefits, such as reduced maintenance costs over the life of the building, energy conservation, improved health and productivity, and flexibility in configuring space at a lower cost.