One of the critical challenges being faced by the humankind today is climate change. As the common man grapples with the widespread environmental damage and its consequences, there is a need to start reforming the wasteful lifestyle. Green Building movement has exponentially grown in less than one decade in India and currently focuses on new building construction sector due to the increasing rates of construction. Despite rapid rates of construction in the country, existing building stock far exceeds that added annually; hence it is critical that policy interventions are made to improve energy efficiency in both new construction as well as existing buildings.
Furthermore, Green building is about reducing operational cost and at the same time increasing human comfort, hence it is a certain fact that even old existing buildings can get benefitted considerably by this concept. Today’s building owners are retrofitting buildings, converting existing buildings into models of sustainability with the aim of reducing the energy bills and increasing the asset value.
Contrary to popular perception, industry interviews and research confirm that many energy-saving initiatives for existing buildings can be achieved with little or no cost. For example, Festival Walk in Hong Kong, a mixed-use commercial complex building built and managed by Swire Properties, one of the biggest real estate companies in Hong Kong and a member of the Swire Pacific Group, changed the control strategy of its air conditioning system in 2004 from a flow-demand oriented logic to a multi-criterion logic to minimize the mismatch of cooling load demand and chilled water flow demand. The investment for such a change was minimal since it only required modification of the program logic, but the energy savings reached approximately 4,00,000 kWh and reduced the release of CO2 by 240,000 kg annually. To identify such saving opportunities like the Festival Walk case in existing buildings, the starting point is to make energy management a business priority for building operators and occupiers. In that way, a building doesn’t have to be new to be green or energy efficient.
In addition to the developed countries where scope for new construction has been shrunk, the green building movement for existing buildings has begun even in developing countries like India due to the fact that building efficiency is key to cutting energy consumption. Buildings account for 16% of world energy consumption with a higher share in developed economies (nearly 40% of total energy use in the United States). In 2007, 878 million metric tonnes of greenhouse gases were attributed to commercial buildings worldwide. In US, while approximately 2% of commercial floor space is newly constructed each year, and a comparable amount renovated, the majority of opportunities to improve efficiency over the next several decades will be in existing building stock, most of which are constrained by old equipment, aging infrastructure, and inadequate operations resources.
As per Architects Journal, “The huge task of retrofitting UK buildings could offer three decades of work for architects, and overshadow new-builds by 2050”.
Paul Finch, Chair – Commission for Architecture & the Built Environment (CABE) says, “There are more than 25 million homes in Britain, most of which do not conform to current environmental standards. If we retrofit 4,000 homes per week, it would give us 30 years worth of work. If you choose to seize it, this is one of the biggest opportunities for architects that we’ve seen in this country for a very long time.”
It is also worthy to note here that 80% of the total lifecycle cost of a building goes in operation and maintenance (O&M) cost while the initial investment is only 20%. Hence, it is important to ensure that the building is operated and maintained in a more sustainable manner.
Ratings for Existing Buildings
There are different ratings available to certify the sustainable and efficient operations in existing buildings and to streamline efforts to promote energy efficiency in the buildings sector viz.
1. Energy Star rating by Environmental Protection Agency (EPA)
- BEE Star Rating for Buildings by Bureau of Energy Efficiency (BEE)
- LEED (Leadership in Energy & Environmental Design) certification by United States Green Building Council (USGBC).
- IGBC Green Existing Building Operations and Maintenance Rating by Indian Green Building Council
Energy Star Rating is focused on energy performance of the building and hence rating is awarded based on the energy consumption and savings of the respective building. An energy star certified facility meets strict energy performance standards set by Environmental Protection Agency (EPA). In order to qualify for the Energy Star, a building or manufacturing plant must earn a 75 or higher on EPA’s 1-100 energy performance scale, indicating that the facility performs better than at least 75% of similar buildings nationwide. The Energy Star energy performance scale accounts for differences in operating conditions, regional weather data, and other important considerations.
Bureau of Energy Efficiency (BEE) has developed a Star Rating programme for buildings which is based on the actual performance of a building in terms of its specific energy usage in kwh/sq m/year. This programme rates office buildings on a 1-5 Star scale, with 5 Star labelled buildings being the most efficient. The scheme is propagated on a voluntary basis and the label provided under it is applicable for a period of 5 years from the date of issue. Commercial buildings or establishments have been included in the list of industries and other establishments under the Energy Conservation Act (2001) and have been notified as designated consumers.
LEED Existing Buildings Operations & Maintenance (EBOM) Rating System, developed by (USGBC) helps building owners and operators measure operations, improvements and maintenance on a consistent scale, with the goal of maximizing operational efficiency while minimizing environmental impacts. LEED EBOM addresses whole-building cleaning and maintenance issues (including chemical use), recycling programs, exterior maintenance programs, and systems upgrades. It can be applied both to existing buildings seeking LEED certification for the first time and to projects previously certified under LEED for new construction, schools, or core & shell.
LEED EBOM is a third-party rating system and tool that provides performance options in:
- Sustainable Sites
- Water Efficiency
- Energy & Atmosphere
- Materials & Resources
- Indoor Environmental Quality
- Innovation & Regional Priorities
Up to 100 points are tallied and buildings can achieve one of four different performance ratings – Platinum, Gold, Silver or Certified.
IGBC Existing Building Operation & Maintenance (EBOM) Rating System is the first rating programme developed in India by IGBC, exclusively for existing building stock. It is based on accepted environmental principles and strikes a balance between known established practices and emerging concepts. IGBC Green Existing Buildings O&M Rating System is fundamentally designed to address national priorities of resource conservation while providing quality of life for occupants. The rating programme uses well-accepted national standards and wherever local or national standards are not available, appropriate international benchmarks have been considered.
IGBC Green Existing Buildings O&M rating system addresses green features under the following categories:
1. Site & Facility Management
- Water Efficiency
- Energy Efficiency
- Health & Comfort
- Innovation
Energy Saving Tips
Taking simple steps can considerably reduce the amount of energy used in a building, which in turn can help save money in the long run. Such simple measures may include the following:
Lighting
- Replace old incandescent bulbs with energy-efficient compact fluorescent lights or LEDs.a. 40-watt fluorescent lamps can be replaced with 34-watt compact fluorescent lamps that produce almost the same amount of light.
c. Install occupancy sensors or turn off lights when not needed. Occupancy sensors have been shown to save up to 30 percent on lighting costs during normal working hours. Lights in storage areas, conference rooms, restrooms, or near windows can be left off when space is unoccupied.
- Install the timers or time clocks to ensure that interior and exterior lights are turned off at the appropriate time. These are generally simple to install and are inexpensive as well.
Air-Conditioners
- Set up thermostat temperature inside the space as per comfort requirements only i.e. not too cool and not too hot.
- Use an interior fan in conjunction with the window air conditioner
Refrigerators
1. Regularly defrost manual defrost refrigerators and freezers
2. Leave enough space between your refrigerator and the walls or cabinets
Electronic Appliances: Buy and use BEE star rated appliances
Improved efficiency of existing buildings through building retrofitting and other measures represents a high-volume, low-cost approach to reducing energy use and greenhouse gas emissions. As India pursues ambitious plans for sustainable development and equitable growth, energy efficiency is an important, low-cost resource. With an emphasis on “whole building” rather than piecemeal approaches, existing buildings can significantly reduce energy consumption and greenhouse gas emissions while producing financial rewards for owners.
AUTHORS CREDITS & PHOTOGRAPH
Ashish K Jain
Partner – AEON Integrated Building Design Consultants LLP
