Green development does not necessarily mean extra cost. Proper planning and right construction practices can actually bring down the project cost.
India’s sustainable quotient has grown substantially over the last decade or so, but the country still has a long way to go. With green responsiveness still restricted to a handful of large-sized construction companies, there is a need to spread sustainable building practices across various levels of the industry.
While most developers still look at green as a unique feature or selling proposition, some have made it an integral aspect of their properties. Unlike residential properties where, once built, the onus is on the users to make the most of the building’s green design, in commercial and self-use buildings, the owners have to consider the operational costs a well. This makes it important to have sustainable buildings that are environment as well as budget-friendly.
Often, developers restrain themselves from getting into green construction, fearing that higher capital cost will dent the project viability. This, along with the fact that besides being able to charge a premium for green projects, there’s not much incentive for developers to go green. However, contrary to this popular belief, there are a number of sustainable practices that not only help reduce cost but also offer long-term benefits in the form of savings in energy and water usage.
For example, developers can look at adopting some easy but cost-effective construction practices to construct sustainable buildings. Major cost in construction comes from the structural materials such as brick, steel, glass, cladding, tiles and ceiling materials. Rumi Engineer, business head, Godrej Green Building Consultancy Services, points out that since materials play a very significant role in construction, it’s critical to select them based on their cost, reliability and life-cycle factors. “To have an energy-efficient structure, one must look at the thermal insulation properties of the material used. For bricks, which are extensively used in all types of constructions, builders can use AAC (Autoclaved Aerated Concrete) blocks and fly-ash concrete,” he says.
Another important criterion for selecting the materials is their availability in local proximity. “Transporting material from miles away from project site will not only add to the cost but also have environmental impact. GRIHA/IGBC Green rating systems encourage selecting materials, which are available locally, and have recycled content and good thermal resistance properties. This proposition adds value to the project and does not have an impact on the overall project cost,” Engineer adds.
Here, we look at some unique materials, designs and technologies that can help developers up their green quotient, without spending a great deal of money.
Radiant cooling technology
Although radiant cooling technology has been around since long, not many developers have used it for commercial buildings. This, despite the fact that a radiant cooling system is easier to install as it requires fewer equipment and the overall cost of the system is also slightly lower than conventional air-conditioning systems.
Infosys was the first commercial building in India to install the radiant cooling technology at its software development Block-1 at Pocharam campus in Hyderabad. The most significant feature of the building is that it is split into two symmetric halves. One half is cooled by conventional air-conditioning and the other half by radiant cooling.
Since there are different seasons in Hyderabad, the project is a good example to demonstrate that radiant cooling is effective even in tropical climates. Also, the system consumes 33 per cent less energy compared to conventional air-conditioning system. These are among the lowest numbers for energy consumption in an office building globally. It provides better indoor air quality and thermal comfort, compared to conventional air-conditioning.
The most important aspect for developers while implementing any new technology is the capital cost involved. In case of radiant cooling, it was found that the capital cost of the system is slightly lower than conventional air-conditioning.
In addition to radiant cooling, the platinum-rated Infosys building has put in place an efficient envelope for better orientation, double walls with insulation, insulated roof and windows with appropriate shading to maximise natural light in the building and minimise heat ingress. The property is about 40 per cent more efficient than ASHRAE baseline. The building has been equipped with energy meters for each equipment of the air-conditioning system as well as radiant cooling system. It also features a building automation system to monitor and control the operation of the building systems accurately.
The project has also been given 5- star ratings by GRIHA.
The benefits of renewable energy—both in terms of environmental as well as savings in energy cost are not unknown to anyone. But many developers wonder whether this technology is viable for their projects; whether it can be used for commercial buildings; what’s the payback period, and so on.
With government subsidy already in place, it makes good business sense to opt for renewable sources of energy—such as wind and solar—to meet energy needs. Solar and wind energy plants need not have to be on the project site. The wind farm can be located hundreds of miles away from the project site, which can be linked to the power-grid and supply power to the project. It is possible to meet 100 per cent of the electricity requirements through wind energy. ITC Grand Chola in Chennai, a 5-star GRIHA rated and the world’s largest LEED platinum green hotel has implemented such a system. The five-star property owns a wind farm of 12.6 MW capacity that caters to 100 per cent of its electricity requirements. The wind farm generates 27,90,0000 KWh units of electricity annually.
Besides wind energy, solar energy can also be tapped to reduce a project’s carbon footprint. One such example is the administrative building of Pimpri Chinchwad New Town Development Authority (PCNTDA) in Pune. Since the building is a government office and not a profit centre, it was imperative for developers to keep the operation costs to the minimum. The GRIHA 5 star-rated project has a 100 KWp solar PV system installed at the site. The low energy footprint and the attractive subsidy offered by the government for rooftop solar PV systems prompted the owner and the design team to consider using solar PV. The solar panel generates 1,45,985 kWh, which meets 86 per cent of building’s energy requirements. At present, the building has 65 per cent occupancy and the entire energy requirement—including space conditioning, process equipment, lifts, pumps, and day and night time artificial lighting—is met by solar power. The ITC Grand Chola hotel also uses solar concentrators to meet 25 per cent of the domestic hot water requirement.
Since the climate is quite comfortable in Pune, the developer of PCNTDA decided to avoid air-conditioning and opted for natural ventilation to enhance indoor thermal comfort by means of solar passive design.
For setting-up a green manufacturing plant, pre-engineered building (PEB) could be the best bet. Since PEBs use 100 per cent steel, which is recyclable up to 90 per cent, it saves primary resources and reduces waste. Such buildings are quick to erect, thereby offering savings in labour and construction cost. Tata Motors’ Dharwad plant is a good example of this. The shop buildings were mostly pre-engineered, which was necessary keeping in mind the deadline for commissioning the plant. Interarch, which was given the contract, had to implement various green features for the manufacturing facility, keeping the IGBC norms under consideration.
The buildings have been designed to use maximum day light (and not heat) which ensures that power consumption for non-process lighting is nil. This was achieved by providing translucent polycarbonate sheets in roofing and cladding. Further, to save time, site roll forming for entire roofing, cladding and liner was done, and more than 72,000 sq. m of roofing and cladding was executed. Window canopies were also fitted to modify the SHGC of window glass. The building also has built windows without canopies that provide lighting as per prescribed SHGC factors. The use of green glass ensures that there is minimal heat gain inside the building.
Other features include use of LED for street lighting, shop general lighting, installing 17kWp hybrid solar and wind power systems to power offices. Interarch installed 4 per cent skylights on the roof of the total roof area of the building and 4 per cent in wall, which reduces the need of artificial lights inside the building and saves electricity.
The plant’s maximum daily water requirement of 2,550 cu.m., was met by taking various water conservation measures. A lake was created for storage of water, which can be processed for further use, besides having reverse osmosis treatment for water recycling.
Interarch also had to implement many innovative solutions like highest safety standards, followed in line with international standard and TML guidelines, to achieve zero accident, logistic and warehousing control at site to meet site standard norms. The plant has already received IGBC’s LEED platinum certification.
Retrofitting for existing buildings
It’s much easier to incorporate sustainable features in new construction as compared to existing building. Besides in-depth understanding of the operations, meticulous planning and execution schemes also need to be rolled out for management to accept the retrofit project.
While it’s a challenging task, scientific planning and analysis of energy consumption can give a clear idea about areas for improvement.
An example of retrofitting could be the 40-year old Godrej Bhavan in south Mumbai. This is the first building in Mumbai and the sixth building in India to have receive the LEED Gold certification from the USGBC under the existing buildings operations and maintenance category.
The project completed its retrofitting in 2010 and within two years it has started to see the benefits in terms of cost and energy savings. The project is on track to recover the costs of installing energy-efficiency measures through lower electricity bills. There has been a reduction in energy usage from 5,94,696 kWh (2009-10) to 5,27,160 kWh (2010-11) to 5,21,856 (2011-12).
The project basically focused on three aspects: HVAC, lighting, and the building maintenance system, that account for the bulk of the energy savings. The upgraded HVAC system captures the maximum savings of the measures installed, accounting for an average of 32 per cent in the overall electricity savings for FY 2010-12.
As is evident from the examples discussed here, going green is not always a costly affair. What is required is efficient planning and designing at the initial stage itself. While the awareness is very much visible at the commercial sector, it’s imperative that developers expand their horizons and do more of residential green buildings. Although it’s worth mentioning that India is not doing badly either when it comes to green building footprint. According to IGBC, India’s green building footprint is 1.4 billion sq. ft — second only to the US.
However, there is a need to have a holistic approach towards sustainability, which must not be restricted to only gaining some points to attain green certification.
Top 10 ways to go green
Rumi Engineer, business head, Godrej Green Building Consultancy Services list down key points developers should keep in mind for attaining green certification.
1. Building envelope materials: Use AAC/concrete blocks with fly-ash content to reduce heat load inside a building.
2. Water use reduction: Use low-flow plumbing fixtures to reduce water wastage. Install sewage treatment plant for recycling of water.
3. Waste management: Install organic waste converters within your premises. The manure collected could be used for gardening purposes.
4. Energy efficiency: Install BEE 5-star rated light fixtures, LEDs and electrical devices such as pumps, motors and water heaters.
5. Rain water harvesting: You can either recharge the ground by installing percolation pits or store the rain water in tanks for flushing and cleaning purposes.
6. Alternate energy usage: By installing small solar or wind power systems, you can take care of smaller electrical loads and water heating.
7. Building design: The emphasis should be on using maximum day lighting but taking care of glare. As per the climatic condition, one can design natural ventilation wherever applicable.
8. Green house gas reduction: Source all building materials locally to minimise transportation.
9. Reduction of heat island effect: Though China Mosaic is an age-old proven methodology to reflect back the heat, one can apply high albedo paint on the roof.
10. Erosion & sedimentation control: Install pits to arrest soil particles/ sediments.