The construction, occupancy, renovation, and demolition of buildings all have extensive environmental impacts of growing concern in the modern world, giving rise to the increased implementation of green building standards and certifications. Of these standards, LEED was the first implemented in the United States, and now holds the title as the most popular in the world.
LEED stands for Leadership in Energy and Environmental Design, and consists of a point-based rating system. The non-profit U.S. Green Building Council (USGBC) developed LEED in the year 2000 to encourage efficiency for all buildings, from residential, to business, to schools and more. It provides a framework for creating efficiency in energy and resource usage during construction, as well as during the operation and maintenance of buildings. The goal is to improve performance for energy savings, water efficiency, indoor environmental quality, CO2 emissions reduction, and resource conservation. To achieve this, the point system evaluates nine categories:
- Location and Transportation
- Sustainable Sites
- Water Efficiency
- Energy and Atmosphere
- Materials and Resources
- Indoor Environmental Quality
- Regional Priority
- Integrative Process
Within these categories exist prerequisites, credits, and points. The prerequisites are the standard items necessary to set a foundation for any building to gain LEED accreditation, while credits are additional actions which earn a builder points towards certification. The more points earned, the higher the certification. The four levels of LEED certification are:
- Certified buildings earn 40–49 points
- Silver buildings earn 50–59 points
- Gold buildings earn 60–79 points
- Platinum buildings earn 80 or more points
The LEED program has a credit library showing all the items that can gain a building points. For example, some specific items include; using a cooling tower, water metering, protecting sensitive land, controlling tobacco smoke, and using carbon offsets. Each item is typically worth one point.
See the Difference Being Made
Given that LEED was established fairly recently and it takes a lot of time to construct and evaluate buildings, it can be difficult quantify how much effect it has had so far. Various studies using NBI-supplied data show that LEED buildings, on average, use 10 to 15 percent less energy on site than comparable conventional buildings. This is less than some sources claiming 30 to 40 percent differences, but still a significant reduction which can likely improve further over time.
As a result, this 10 to 15 percent difference leads to 80 million tons of waste diverted from landfills, and a reported 34% reduction in greenhouse gas emission. According to the USGBC, LEED Gold certified buildings also use 11% less water than conventional buildings, have 19% lower maintenance costs, and reduce sick building syndrome. Sick building syndrome is a fairly mysterious condition related to time spent in a building. It is likely caused by factors of indoor air and environmental quality, resulting in lower worker productivity and higher absenteeism. LEED requirements improve indoor environmental quality, likely contributing to the alleviation of these symptoms.
Benefits for All
LEED certification helps extend the owner’s marketing reach by listing them on the USGBC website of LEED Professionals. Beyond looking good to the public, LEED certification has other tangible financial incentives. Specific companies have reported significant savings from LEED certified buildings. For example, Bank of America reported a $227 million energy cost savings in LEED facilities since 2004. Adobe Systems gained a 20 to 1 return on investment from its headquarters LEED project. And 30% of firms built green in 2012 to lower operating costs. Over time, LEED certified buildings retain higher property values and sell faster and for higher prices.
Another significant factor for both commercial and residential building owners is tax incentives and rebates. While there are currently no direct federal tax incentives for LEED certification, there are incentives at the state and local levels. Tax credits and rebates are common, with a 30% rebate for existing homes completing a LEED-H rehab. A 30% credit is also available for installation of renewable energy systems or geothermal HVAC systems.
Businesses and homeowners can also obtain better loans, net metering availability, and decreased maintenance costs over time. The logic in receiving higher-than-average loans is that you will have more spendable income from lower utility bills. On the other hand, net metering gets you direct credit or cash for generating power from a renewable energy system, such as solar panel roofing. Over time, the USGBC estimates that green retrofitting such as this will lower operating costs by 9% per year.
The Long Term: Cleaning and Maintenance
The environmental and financial impacts of a building exist throughout its life cycle, from construction to demolition. But demolishing an old building to make way for a new one causes especially heavy and long-lasting environmental damage, making maintenance of existing buildings vital. LEED for Building Operations and Maintenance (LEED-EBOM) focuses on these aspects, including green cleaning, landscape maintenance, recycling, indoor air quality, transportation programs, green purchasing practices, mechanical systems performance, and waste management. The LEED-EBOM program is particularly useful for existing schools, retail buildings, data centers, and warehouses.
Moreover, cleaning and maintenance activities alone can contribute up to 10 points to a LEED certification. That’s 25% of the basic 40 point certification requirement, with items that are relatively inexpensive and easy to implement. The primary components of the green cleaning requirements for LEED are ensuring the use of environmentally friendly products and the mildest cleaners necessary for each job. The LEED-EBOM program also addresses: the consistent use of sustainable materials, such as paper products and trash bags; chemical concentrates with appropriate dilutions which can minimize chemical use; maintenance personnel properly trained in the hazards, use, maintenance, disposal, and recycling of chemicals, equipment, and packaging; and sustainable practices regarding water usage, energy efficiency, and indoor air quality.
As buildings account for over 40% of the world’s energy use, the continuation of green building practices is crucial. Already the amount of new green non-residential construction in the US has increased to between 40 and 48 percent. Over time, the effectiveness of green practices will only continue to increase and have a profound impact on environmental sustainability.