How to Think About Building Green (3)
LEED Categories
Now let's go through LEED’s different sections so that you can get oriented to various aspects and issues related to green building - in plain English, without technical jargon.
The choice of a building site is usually the single most important environmental decision in the entire building process. Choosing to renovate or expand an existing facility - such as the Felician Sisters in Coraopolis, Pennsylvania did with their convent and school shown here, lessens a building project's environmental impact. To learn more about this project, click
here.
Sustainable Sites
Perhaps the most important decision you make in terms of the environmental impact of your building project is your selection of the site where you build, and how your building relates to its new home. Studies show time and time again that site selection, and the ways in which a building is situated within its site, are almost always the most important factors in a building’s environmental performance.
The LEED standards ask you to consider questions such as
- Where have you chosen to build? Is it in an urban setting, where you can minimize the impact of your building on the land by renovating or using the shell of an existing building? Or is it in a more suburban or rural setting where the way in which your building sits on and relates to the land needs to be carefully considered to minimize its ecological impact?
- With construction, new site stewardship challenges emerge. How will you minimize the disturbance to the land during the course of construction? This may take the form of minimizing storm water runoff which pushes topsoil into nearby sewers or streams, or making sure there's minimal air pollution from windblown dust or mechanical equipment during the construction process.
- How will people get to and from your site? Are there ways you can plan for your site to be more easily accessible to public transportation, or to accommodate commuters who bicycle part of the way to work or to a mass transit stop? Are there ways to plan your project so that your site encourages people to walk more within your community?
- As a steward and neighbor, you will also want to plan to keep some things on your site from leaving it. How will you handle runoff from rainwater on your roofs and parking lots? How will you keep your lighting from spilling off your site? How can you plan ways to keep your building and parking areas from becoming “heat islands” that trap and radiate excessive heat during the summer months - a concern which is particularly important in urban communities?
Specific strategies, outcomes and measures for these kinds of concerns are described in detail in USGBC's section on "sustainable sites."
Low-flow faucets and toilets, like the ones shown here, can substantially reduce the amount of water used in a facility.
Water Efficiency
In the summer of 2007, the southeastern US experienced severe water shortages due to years of suburban sprawl, poor water use planning, and a very dry summer. Suddenly, the importance of water conservation became very clear. The LEED standards emphasize this topic.
LEED asks you to consider:
- As you plan your project, how can you reduce or even eliminate the use of potable water for landscape irrigation, through the plantings which do not require large amounts of water or though the use of non-potable sources of water such as captured rain water or recycled gray water (waste water that is pure enough for irrigation uses)?
- What kinds of water use reductions can you achieve within your building, through the kinds of faucets, toilets and other fixtures you choose and the kinds of water recycling and gray water or wastewater treatment you can host on your site?
Energy and Atmosphere
LEED offers more possible points in the category of "Energy and Atmosphere" than in any other aspect of green building. This reflects the importance USGBC places both on mitigating global warming and the economic benefits of lowering energy costs.
LEED acknowledges the technical nature of this aspect of green building by requiring you, if you applying for LEED certification, to retain a "commissioning agent" (often someone with an engineering background), who verifies--on your behalf--that your building's energy systems are installed, calibrated and perform according to the energy requirements you established with your architect and engineering team.
Even if you are not going to apply for LEED certification, it is essential for you to be satisfied that your architect, engineers and contractors have the commitment and technical experience to deliver truly green energy systems.
Energy efficient lighting fixtures and solar photovoltaic panels - both shown here - help buildings use less fossil fuel and reduce their carbon footprint.
Here are some of the questions raised in this section of LEED:
- How have you approached the design and construction of your building's envelope--from the exterior side to the interior side of your outer walls and roof and ceilings? Do the building materials, insulation, and windows (both their placement and specifications) you have chosen help reduce the energy your building will need?
- How will you circulate air through your building? For the warmer weather, can you design your building to be comfortable without needing refrigerant –based air-conditioning? If you do use this kind of air-conditioning, can you install a system that does not use CFCs (chlorofluorocarbons) which deplete our atmosphere’s ozone layer?
- For heating both your air and water, how efficient is the fossil fuel (oil, gas or electric) system you install as measured by today's accepted benchmarks? (Such as are set out by the American Society of Heating, Refrigerating and Air-Conditioning Engineers – also known as ASHRAE - or the U.S. Dept. of Energy.)
- Can you reduce your use of fossil fuels further with renewable energy generated at your site, through the use of solar cells or a geo-thermal system? Or, can you achieve such reductions through accessing renewable energy "through the grid" by purchasing some or all of your energy from a renewable source?
- Can you reduce what's called "process" energy--that is, the energy required by your appliances and machines (from refrigerators to computers to elevators, etc.) by how you design your electrical system, as well as through purchasing "Energy Star" appliances that are certified to use less energy than their traditional counterparts?
- Have you integrated the design and placement of your windows, the lighting fixtures you install, and the appropriate kinds of sensors and controls so that the people in your building get the best light in which to live and work as efficiently as possible?
These are some of the aspects of energy and atmosphere for you to consider as you plan your project. Be aware that achieving many of these things is best done by having your engineers create a computer-generated simulation of how the energy systems in your building will work. This simulation can guide you in your decision-making. Your LEED commissioning agent will use it to analyze how efficiently your building actually works when it is completed.
As is true for other aspects of green building, you have the best chance of meeting your goals for energy and atmosphere at the least expense when your planning addresses these questions early on.