So you are thinking green! Whether it is an existing building or a new construction, there are several ways of going on the green path. But the best green buildings will always include the following:
The best ‘site’ forward
Good site selection is the foundation for a green building. Do not build on sensitive habitats like wetlands, flood zones or endangered wildlife habitats. Consider a reclaimed brownfield, in-fill and greyfield sites (previously developed site with all utilities in place) instead of clearing greenfields or undeveloped lands. Proximity to mass transit and community resources will go a long way in not only minimising automobile dependence but also in creating strong self-sustainable green communities and neighbourhoods.
Cluster buildings on the site to minimise environmental impact. Build up instead of out and keep roads and service lines short. Orient the buildings on east-west axis and take advantage of existing vegetation on the east and west sides of the buildings to reduce cooling loads. Use shrubbery to channel cool air into the buildings. Design landscapes to avoid stormwater runoff into sewers and facilitate on-site rainwater harvesting.
Energy miser building
Design a thermally efficient building shell using high levels of insulation and performance windows, light colours for walls and roofs and minimum use of glass on east and west sides. Tie in renewable energy sources like solar, wind and geothermal to your regular resource. Passive design strategies like building profile and orientation, natural lighting and passive solar design will affect building energy performance positively. Reduce electric loads from lighting, equipment and appliances.
Material as cultural and energy resources
Pick sustainable building materials which have recycled and reused content, low harmful gas emissions and sustainably harvested materials that are locally available. Use dimensional planning and other material efficiency strategies that will help reduce the building materials needed and construction costs.
A life cycle assessment (LCA) will help assess a full range of impacts like embodied energy, global warming potential, resource use and pollution, associated with cradle-to-grave stages of a process: from extraction of raw materials through processing, manufacture, distribution, use, repair and maintenance and disposal or recycling.
Design dual plumbing to use water from sinks, showers or clothes washers (graywater) for reuse in water closets and landscape irrigation. Water efficient equipment like water conserving toilets, shower heads and faucet aerators not only reduce water use, they reduce demand on septic systems or sewage treatment plants too. Reducing hot water use saves energy. Rainwater harvesting can be used to cool the buildings and for irrigation. Use mirco-irrigation to water nonturf areas and state-of-the art irrigation controllers. Design xeriscapes or landscapes with drought resistant native plants and perennial groundcovers.
Good environmental quality in the buildings will enhance work efficiency and reduce respiratory diseases and allergies. It is imperative to choose construction materials, interior finishes, adhesives, sealants and paints with low volatile organic compounds (VOCs). High efficiency ventilation and in-duct filtration is needed for good indoor air quality. Install entryway dirt capturing systems.
Reduce, reuse, recycle
The greenest buildings may be old buildings restored for adaptive reuse. Recycle waste during the construction process. Reduce landfill pressure and save natural resources by using salvaged materials like lumber, millwork, certain plumbing fixtures, and hardware. Test for lead paint and asbestos without sacrificing energy efficiency or water efficiency by reusing old windows or toilets.
Operations and maintenance
Green building strategies do not mean much if they are not used as intended. Building commissioning is imperative for successful functioning of a green building. Regular testing and adjusting the mechanical, electrical and plumbing systems is needed to ensure that all equipment meets the design criteria. It includes instructing the staff on the operation and maintenance of the equipment. Over time, building performance can be assured through measurement, adjustment and upgradation. Proper maintenance ensures that a building continues to perform as designed and commissioned.
Vani Bahl, Principal Arcriam Associates is LEED AP BD+C, is founder of GreenExamGuide.com and Member of International Society of Architectural Historian