Posted December 14, 2010
During a recent design meeting for a new construction office building, our team was surprised to realize that after reviewing the preliminary scorecard, we would be undergoing a difficult challenge to achieve a goal of LEED Silver Certification. With all the recent LEED Silver, Gold and even Platinum office buildings in the Denver area, this came as a bit of a shock to the team. Why was it so difficult to achieve LEED Silver on this project when a newly constructed building down the street of similar size and occupancy was certified LEED Gold?
What the team (and many others in the industry) did not realize is that the new LEED v3 requirements are impacting how to achieve LEED certification. Mentioned below are some "big picture" items where the most significant changes have occurred.
1. Minimum Program Requirements are now required during the LEED registration process. This means that the project must meet these requirements to even register for LEED certification. Examples of the minimum program requirements include the following:
2. The overall point system has changed under LEED v3. One of the biggest impacts is not simply the change in overall totals, but the fact that the individual credits are weighed differently, which can make an impact on design decisions.
3. Regional Priority Credits is a new category where four points can be awarded if you are already achieving these credits within the main categories. These "bonus points" are determined based on the project's zip code. You can find a link on the USGBC website to determine which credits can be achieved. For example, in the 80202 zip code the project can qualify for two sustainable sites, two water efficiency credits and two energy and atmosphere credits.
4. EAp2 & EAc1 - Optimize energy credits. To achieve this credit, engineers design two energy models, one based on the design intent of the project and the other based on the minimum baseline design per ASHRAE 90.1 standards. There are two significant changes for the prerequisite and credit. The first is ASHRAE 90.1-2004 baseline which has been updated to the 2007 standard. Mechanical engineers working with these baselines have said it is significantly more difficult to achieve the prerequisite under the 2007 baseline. Secondly, the savings requirements have been altered. Under LEED v2.2, the prerequisite's only requirement was to prove that the design intent met the minimum ASHRAE 90.1 2004 baseline model. In order to achieve a point, the energy model would need to prove a 10.5% cost savings above the baseline. Under LEED v3, the design team must prove a 10% energy cost savings from the ASHRAE 90.1 2007 baseline just to meet the prerequisite. A project will not receive 1 point until a 12% energy cost savings is achieved.
5. WEp1 & WEc1 - Water Reduction credits. LEED v2.2 did not have a prerequisite for water reduction. To earn the first point, the team had to demonstrate a 20% water reduction savings per the EPA 1992. Now the 20% water savings is a prerequisite and it is not only the EPA 1992 guidelines that have to be met, but also the LEED v3 baselines as well. Currently the LEED baseline requirement is installing a commercial public lavatory at 0.5 gallons per minute (gpm) flow fixtures, whereas the previous baseline was 2.5 gpm. To put this in perspective we compared the LEED v3 WE reduction templates with LEED v2.2 template, using the same number of occupants, same fixtures, number of days, etc… The outcome was a 35% water savings under LEED v3; under LEED v2.2 we achieved a 46% water savings. This results in 3 out of 3 points under LEED v2.2 and 3 out of 5 points under LEED v3. While the number of points is the same, we only achieved 60% of the possible points versus 100%. Remember the total number of points needed is greater, so it is important to maximize the total percentage of available credits.
With the changing requirements of not only LEED, but government sustainable standards and industry organizations such as ASHRAE, there will continue to be a push for the design and construction industry to find new ways to meet clients' demand for high performance buildings. With these changes, it does not mean it is impossible for projects to still achieve LEED Gold Certification. Successful project teams need to analyze the scorecard and understand the new changes in order to set a realistic LEED certification goal - this includes the owner, developer and design and construction team.
The larger impacts of changing requirements will also have an impact on both private development and government owned buildings. The commercial and corporate building market utilizes LEED as a tool for either marketing their buildings or to enhance their image. As the requirements for LEED rating certification changes, how will the market compare? For example, how will a LEED Platinum building under version 2.2 compare to a LEED Gold building under LEED v3? In addition, 34 state governments and many federal agencies have their own ordinances and policies for green building with the majority of them mandating LEED Silver certification. Will these government agencies review the impact of these requirements to determine if this is still the right goal for their buildings?
Only time will tell the full impact of these changing requirements, but the first step is education in the industry to ensure everyone is aware of the changes and potential impacts.