Green Buildings 101
Everyone knows that “green building” is not about the color of the paint, but no single definition exists to define exactly what makes a building green. Rather, there are multiple elements to consider, and ongoing debate about which should be given the most weight.
There are, however, common themes to almost all definitions of green buildings, all of which relate to the building’s ability to provide a comfortable and productive space, while minimizing environmental impact throughout the entire life cycle. In general, buildings that aspire to be green strive to get the most out of every unit of energy, water, and other resources - saving money on energy, reducing environmental impacts, and raising value and competitiveness. Third party green building rating systems vary, but most tend to focus on five basic areas of concern, as depicted in the diagram1 at right:
Much of a building’s environmental impact can be determined before holes are dug and concrete is poured. Thinking sustainably begins long before the first shovel breaks ground, and starts with the choice of site selection and preliminary design.
Choosing to construct on a “brownfield” site (previously developed site contaminated by a hazardous substance or pollutant) in a dense urban area is one example of sustainable site planning. While choosing such a site for a project can present environmental challenges--dealing with debris and possible contamination, for example, it also has numerous environmental benefits. Choosing a brownfield site can mean that an alternate undeveloped area remains natural, minimizing urban footprint. In addition, brownfield sites are typically found in densely populated urban communities, where a construction project has the dual benefit of invigorating the local economy and encouraging occupants to walk, bike, and take public transportation where available.
The availability of fresh water has become an area of mounting concern as both developed and developing economies experience scarcity and increased competition for finite resources. Green building design should incorporate efficient water use. Managing wastewater, irrigation water, and storm runoff are also important to a sustainable approach.
In some buildings, rain is harvested, processed and reutilized for non-potable applications. Solutions of this nature can reduce the requirements for fresh water from municipal systems while at the same time avoiding the spread of pollutants through storm water runoff. Green roofs represent another emerging tool to prevent storm water runoff while adding to urban green space and providing a host of other benefits.
The environmental impacts of fossil fuel extraction and the threat of climate change make energy use a critical sustainability issue. Buildings use energy through direct combustion of gas or fuel oil, as well as the consumption of electricity, which is supplied primarily throughout the world via the burning of fossil fuels. But even as buildings require more and more energy to power computers, servers, and other equipment, designers are making strides to counter such demands by embedding efficiency deep within projects. Orienting the building to minimize solar radiation, including high grade windows and insulation and incorporating daylight into the design are just a few of the many ways to design an energy efficient building. Additionally, the appropriate selection of HVAC equipment and building systems controls are critical to the efficiency of any building.
Building construction will always require natural resources. But green building design can minimize impact by selecting salvaged materials, renewable materials, recycled materials, or materials sourced close to the site to reduce the impacts of the building over the course of its life. Diverting construction waste from landfills to recycling applications is an important element of sustainable management of materials.
Indoor Environmental Quality
Sustainability includes consideration for the short- and long-term health of occupants. For this reason, green building design typically incorporates measures to improve the air quality inside the building by selecting materials that do not release hazardous chemicals or compounds and providing adequate ventilation, temperature, humidity and lighting. Healthy indoor environments are being viewed increasingly as key not only to the health of occupants, but to their satisfaction and productivity, as well.
Project Profiles – Case studies of new green building construction from the U.S. Green Building Council.
EPA Green Building Publications – Publications list with info on brownfields, water management, indoor air quality, energy efficiency, materials recycling/reuse, and more.
1 U.S. Green Building Council