10 Facts About the LEED Ratings System

LEED may be an international certification, but recently the USGBC has phased in credits for green building practices tackling region-specific environmental problems. The new "regional priority credits" were introduced in 2009, as part of an overhaul of the LEED ratings [source:U.S. Green Building Council]. You can get up to four bonus certification points for upgrades to your home that help solve local environmental problems [source:U.S. Green Building Council]. For example, if you live in a rural area, you might be able to get bonus points for landscaping that prevents erosion into irrigation water for nearby farmland. If you live in a sunnier clime, such as the southeastern United States, installing solar panels might net you some bonus points. There are special credits for each of the 50 states, as well as Puerto Rico and international projects, too.

Since part of the purpose of LEED is to reduce the pollution created by buildings, guidelines that reduce energy consumption make sense. But when reading through the LEED guidelines, it might surprise you to learn that the program awards points for steps that improve the interior air quality of a building, too. For example, if you add air filtration and moisture control systems to help reduce molds and allergens, you can score points. There are also some health and safety guidelines, like preventing HVAC vents from connecting between garages and living areas, and making sure there are exhaust vents installed in kitchens. Other guidelines are more focused on personal comfort, including a prerequisite requiring LEED-certified homes to have even heating and cooling throughout the house [source: U.S. Green Building Council]. But what does a person's comfort have to do with helping the environment? According to the USGBC, the air quality inside is usually worse than the air quality inside, and can lead to health problems just like air pollution can [source: U.S. Green Building Council].

Location counts when you're going for LEED certification. There are bonus points awarded for where a home is built (or, in the case of a renovation, where it's already located) in relation to other buildings, neighborhoods and surrounding infrastructure. For example, your home qualifies for points if its site is within a half mile of water and sewer lines, because that can prevent resources from being used and land from being disturbed to install additional infrastructure [source: U.S. Green Building Council]. You can also claim points under LEED if your home is built close to other neighborhoods, communities or groups of buildings.

That might seem strange. Isn't part of the LEED program's goal to reduce destruction of the natural environment? Yes, but more dense construction makes it easier to walk places or use more environmentally friendly transportation, including buses and trains [source: Centers for Disease Control and Prevention]. And LEED does have measures to make sure certain environments won't be disturbed. Homes can claim points for not being located on floodplains, near wetlands or endangered species' habitats, or on reclaimed park land. Regardless of your site, you'll earn LEED credits if it has any "no disturbance zones," areas where no trees or plants can be disturbed [source: U.S. Green Building Council].

All LEED-certified homes are required to meet ENERGY STAR standards as a prerequisite of the program. ENERGY STAR, a program set up by the Environmental Protection Agency and the Department of Energy, sets up a voluntary baseline energy efficiency standard for homes. To be certified as an ENERGY STAR home, your house must be around 20 to 30 percent more energy efficient than the average home [source: U.S. Environmental Protection Agency]. For example, homes can meet that efficiency level through a combination of factors. Installing better windows and insulation can reduce the amount of energy used by HVAC systems by keeping homes cooler longer in the summer and warmer longer in the winter. There are also special ENERGY STAR-certified appliances and light bulbs that use less energy. You can earn extra points if your LEED home's energy efficiency improves on ENERGY STAR's minimum efficiency standard [source: U.S. Green Building Council].

"Awareness and Education," one of the LEED guidelines' nine areas of green homebuilding, might seem like it doesn't have much to do with protecting the environment. But the certification standards include credits for educating tenants or homebuyers about how to use a LEED home to its full sustainable, energy efficient potential. If you're working with a LEED builder or developer, the home can score points if the builder fills you in on how to keep the home energy efficient over the years. For example, the builder could provide you with detailed instructions for using the rainwater recycling system and how to limit water use in the home [source: U.S. Green Building Council]. If you rent your home out, you can claim points for making the same effort.

The logic behind these credits is simple: A property is only as an environmentally friendly as the way it is used [U.S. Green Building Council]. State-of-the-art ENERGY STAR appliances aren't really saving energy if the person who uses them runs an entire washing machine cycle to clean one shirt. Windows and insulation that trap heat are pretty much useless if the homeowner runs the heater all winter and keeps the windows open.

Recycling and conserving resources is familiar to most of us these days. But conserving construction materials? That's not something most people think about on a daily basis. LEED guidelines, however, cover pretty much every stage of a home's life, including the actual construction process. So, builders looking for LEED certification are required to make the most out of framing and building materials, such as beams, studs and roofing materials. [source: U.S. Green Building Council]. The limits on waste are extremely specific. There is a specific maximum amount of waste for each type of building material; for example, only 5 percent of all studs used can be wasted, and absolutely no roof decking can be put to waste [source: U.S. Green Building Council]. A maximum of 8.3 percent of the building materials budget can be spent on supplies that are eventually wasted [source: U.S. Green Building Council]. So if you're going for LEED certification for your new construction, make sure the builder understands the importance of conserving materials.

The urban heat island effect might sound like some sort of comic book superpower or the premise for a dystopian science fiction movie, but it's actually a real world phenomenon. Because of high concentrations of concrete, metal, stone and other materials that absorb a lot of sunlight, urban areas are usually hotter than rural or suburban areas that have more green space [source: U.S. Environmental Protection Agency]. LEED standards try to limit this effect by awarding points for using a variety of methods to reduce that ambient heat. Driveways, sidewalks and patios can be built using special "high-albedo" building materials, which.reflect -- instead of absorb -- a majority of the sunlight that hits them [source: U.S. Green Building Council]. An albedo is a unit of measure used to gauge a material's reflectivity. High-albedo materials are any that reflect most of the sunlight that hits them [source: Taha].

Your home can qualify for points without using those special high-albedo materials. Instead, you can use plants and trees to shade reflective areas. Like most sections of LEED standards, the guidelines for how to provide this shade are extremely detailed and mathematically complex. To win the points, 50 percent of reflective areas have to be shaded. You will need to calculate that percentage based on the day of the year when shadows are the smallest; to be exact, shading should be calculated for June 21 at noon when the sun is directly overhead [source: U.S. Green Building Council].

LEED standards focus on the landscape design of a home, not just exterior and interior features of the building itself. The guidelines pay particular attention to how much grass you can plant. Anyone who takes care of a sprawling green lawn understands the amounts of water required to keep grass growing and bright green. LEED understands too, and so they give credit toward certification for homes that use less "conventional turf" (in other words, a grass lawn) [source: U.S. Green Building Council]. Those points are weighted depending on what percentage of your yard is covered in grass. For yards covered 20 percent or less by conventional turf, you can net three LEED points. No points are awarded if the turf takes up more than 60 percent of the yard [source: U.S. Green Building Council]. Other stipulations over the use of grass include a ban on turf in shaded areas, or in areas that are steeply sloped. No matter what percentage of your yard is taken up by the lawn, you need to make sure all of the grass is drought tolerant to qualify for any points. The USGBC recommends using mulch and other plantings to cover the rest [source: U.S. Green Building Council].

Water conservation is a major focus of LEED guidelines, and the standards that you follow when certifying your home include several different ways to qualify for points for water recycling and conservation. One option for conserving water is harvesting rainwater. By installing systems of troughs and barrels to collect runoff from the roof, you can use rainwater to water plants in the yard, or even for drinking (once it's been filtered). You can also qualify for points if you install a gray water recycling system in your house [source: U.S. Green Building Council]. Gray water is non-potable water leftover from clothes washers, sink drains and showers that isn't safe for human consumption [source: Barker]. Like harvested rainwater, you can use it to irrigate outdoor plants, or install a system that recycles gray water to make it potable. Both of those solutions win LEED certification points. Those systems can be expensive to install, but you can make up for the cost through long term savings in utility bills. Some regions of the country even have their own municipal gray water systems. Hooking up your home to one of those systems can qualify it for certification points, too [source: U.S. Green Building Council].

The LEED guidelines are extremely detailed, extensive and complex. As you can tell just from this list, they painstakingly track hundreds of measures that can make a home more environmentally sustainable.

But you can also claim points for green improvements that the USGBC has never even thought of. The program sets aside up to six bonus points for environmental improvements that go above and beyond what LEED has outlined in its guidelines [source: U.S. Green Building Council]. Obviously, it might not be possible for every individual to come up with some revolutionary new idea in environmental construction. Even builders or contractors that you hire might not have many fresh ideas, unless they have training in green construction. So, if you want to aim for the highest LEED certification level but don't have the foggiest idea how to exceed the standards, you can hire LEED accredited contractors, architects or designers. LEED accreditation provides special training in environmental construction and technology. Hiring one of those professionals can net you the six bonus points, and save you the time of trying to invent the next great energy-saving technology [source: U.S. Green Building Council].