An Introduction to LEED.
As usual we will not attempt to go into an exhaustive analysis of LEED and it's processes. Think of this as a simplified guide for any client/ developer or interested party about LEED. The USGBC provides plenty of information regarding LEED on it's web site and the different reference manuals available. This summary is for LEED-NC or LEED for new construction version 2.2 which normally involves commercial buildings. We will publish a summary about LEED CS (Core and Shell) and LEED-H for homes at a later time, so keep on checking our web sites.
Do note that since we are writting this summary, it is based on our personal experiences, opinions and subjectivity. We encourage you to learn more about LEED directly from the USGBC and their reference manuals.
We don't believe that the original LEED system was ever meant classify all types of buildings in all environments/ climates. At present it is more focused on mechanical systems for cooling and heating. There are no points at present for a building design that successfully cools itself using passive ventilation without the incorporation of a HVAC system. It used to be that you could achieve a LEED certified rating without really trying to reduce energy usage or consumption of the building. Understanding that huge discrepancy, the USGBC recently (June 2007) mandated that projects would need to obtain 2 points in the Energy & Atmosphere Credit 1: Optimize Energy Performance. This requires a 14% improvement in energy performance of a new building or a 7% improvement for existing buildings.
These recent changes are an improvement but for projects that tend to wait till the last minute before considering LEED, it might mean the present design would require significant design changes.
LEED isn't perfect but is probably the best known, fairly comprehensive and widely accepted green rating system for buildings at present. It is important to realize that the best implementation of LEED is to ensure a totally intergrated building design, whereby any design strategy is coordinated with other elements being incorporated within the building. Just shooting for points will probably allow you to achieve "LEED certified" but it doesn't ensure a building that performs well. An example maybe providing daylight to 75% of the spaces (EQ 8.1) with operable windows (EQ 6.1) every 200sf but not anticipating solar heat gain from west facing windows or optimizing mechanical systems to adjust for open windows. Moving forward with LEED shows an interest in going "green" but it requires a desire to have a integrated building design to truly commit to being sustainable or "green". A integrated building designed to LEED standards should pay for itself through energy efficiency, lower maintenance & operational cost, higher productivity, human comfort and great community public relations. We encourage all projects to undergo a post occupancy evaluation to better understand the cost savings and improved performance achieved through the sustainable design strategies employed. Preferably a survey carried out by a reputable organization which has a extensive database of buildings to use as a baseline for comparison.
Note: LEED 2009 with regionality credits and other significant changes is due to roll out spring of 2009.
Gerard Lee Architects offers LEED Administration services. Read more here
The Different LEED Products:
There are many different types of buildings and projects, and in order to properly document and certify the projects that may not fall neatly into any one category, the USGBC has developed six different products and has a few under development. The trick is to understand which is most appropriate for your project type and follow the guidelines to achieve the appropriate LEED certification level.
Note that even as you read this, the USGBC is still evolving these standards and creating new ones for other building types with input from their respective industries.
These LEED products are:
These are fairly self explanatory. NC stands for new construction and major renovations.
LEED-EB Existing Buildings tends to be a facilities exercise that addresses operations and maintenance issues for building/ property owners and service provides.
LEED-CI Commercial Interiors deals with tenant improvement projects.
LEED-CS Core & Shell are geared towards buildings that have only an exterior shell, vertical circulation and key mechanical, electrical & plumbing systems provided. (Additionally, it requires that the building owner have less than 50% control of the interiors. It is also unique that it allows for LEED pre-certification which can help in marketing a building even before it breaks ground).
LEED-H Houses is geared towards residential buildings.
LEED-ND Neighborhood Developments is still under development and is targeted at large campuses and new towns.
LEED-S, Schools is geared towards new construction and remodels of K-12 schools.
The basic steps in the LEED approval process are to:
1) Register the project with the USGBC
2) Prepare documentation (letter templates, supplemental information, etc.)
3) Request any CIRs
4) Assemble documentation
5) Submit to the USGBC
6) Respond to audit requests
7) Final approval
LEED-NC Rating System
Can be broken down into 5 categories:
There are a total of 69 possible credits available. It is not possible to earn all 69 credits (i.e some credits
like SS Credit 2, Development densities, would not apply if you are building in a remote area).
There are four levels of certification and you have to achieve at least 26 out of the 69 possible points to achieve
the lowest level which is LEED certified.
The ratings are distributed as such: Certified= 26-32; Silver= 33-38; Gold= 39-51; Platinum= 52+
Note that it is advisable to try to gain more credit points than the minimum required for the rating level your project is shooting for. It is highly likely that you will not be granted all the points you submit for. You get a point just for having a LEED accredited professional on your design team. It helps to have a LEED accredited professional on board the team to help the design team understand credit requirements, document the credits, submit CIRs and to develop the right sustainable strategies for the project. Some projects tend to bring on board a LEED Administrator to help guide the team through the process. (Providing LEED Administration services is just one of the many services we supply and have helped several projects review/ evaluate their designs for LEED certification). Note: People are accredited , buildings are certified.
There are 7 prerequisites which are not evenly distributed among the (5) categories. ALL prerequisites must be earned in order to earn any credits. Even if you score well over the number of credits required, just missing one prerequisite will mean that your project will not qualify for any certification level.
Also note that while EA credit 1 (energy optimization) is not a pre-requisite, it is mandatory to earn at least two points. So it may as well be considered as such.
CIRs: Credit Interpretation Requests:
Are a way to appeal to the USGBC for an interpretation of a design strategy not specifically covered by LEED guidelines. CIRs are a resource that a design team should research to help them better understand the USGBC's stand on a particular credit. CIRs are available to a design team once they register their project and gain access to the LEED project web site. There are costs associated with requesting a CIR.
Excel spreadsheets designed to organize/streamline submissions and keep track of progress. Most of these are now completed online via the USGBC web site. There are some spreadsheets still available to help with the calculations. These letter templates have different uses. Some are declarations that specific requirements have been met for a credit. Others are checklists with required documentation and the rest are calculations. A selection of credits will be audited which will require submission of additional information to support the credit requested.
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Benefits of going with the LEED system:
The overall desire of utilizing LEED is to try to achieve "green" or sustainable buildings. This helps reduce negative environmental impacts, reverses the trend of unsustainable (current) construction practices, reduces building operating costs, increases occupant productivity (reduces sick days), creates a sustainable community, maximizes return on investment, enhances marketability (see the recent advertisement campaigns by major corporations) and hopefully aligns with any sustainable mission statement a corporation or individual has implemented.
Sustainable design has been around for a long time. It's not something that came about recently or as a result of new rating systems like LEED or Green Globes. However, these new ratings systems are a viable tool for defining how "green" your building really is. The LEED system is taken from a whole building perspective and up till now, entirely voluntary (though many state and federal projects require a LEED rating on their projects) and is based on accepted energy/environmental principles and emergent technologies. It enables a project to obtain a third party verification of its sustainability and can qualify for state or local government incentives or tax breaks.
The USGBC which promotes and oversees LEED is a non-profit, volunteer organization started in 1993, comprised of members from all aspects/ fields of the building industry (contractors, suppliers, manufacturers, engineers, architects etc.). Its goal was to transform the marketplace and as such we believe it has done so because of the wide spread acceptance and use of the LEED rating system. One of the reasons why it is successful and has been willingly adopted is because all stakeholders in a project have to be involved early within the process. The client, design team and (whenever possible) the contractor should, be involved in the decision making process for the categories or credits the project will attempt to secure. If there is no buy in among the stakeholders, it quickly falls apart.
As noted above, LEED isn't perfect but it remains a fairly well balanced rating system and until a better system emerges, the de facto standard for now.
It is best to incorporate LEED from the inception of the project. While some projects have chosen to do so at the late stages of design or construction documents or even construction, it invariably results in higher costs. This is the perceived "green premium" everyone talks about. However it should be looked at subjectively. If changes (adds) were made to any project at a late stage, it would result in additional costs.
Recent studies have shown that LEED platinum and Gold level projects that involved an intergrated design early in the process have no added hard costs but do result in significant long term operational savings. By implementing the process early on, the design team can work together to ensure that the design attempts to optimize the different "green" strategies to best effect. Similarly, they can source out regional manufacturers (saves on transportation costs and lessens the effect of pollution) and or find appropriate materials that are healthy and contribute to LEED points.
However regardless of the path chosen it is important to not just apply credits or points for the sake of increasing the project score.
A "Green" building still needs to be designed according to sound principles. It still needs to have best practices incorporated in regards moisture control.
Your design team and specialist consultants need to study the climate and then apply LEED credits appropriately.
I.e. LEED NC -Indoor environmental quality EQ credit 3.2 involves a building flush out of the mechanical systems. In theory it is good practise. However if this is done in a climate with high humidity or on a humid day in moderate climates, and no proper pre-cautions are enforced, there is a possibility that large amounts of moisture maybe introduced to the interior of the building. This could create an environment that promotes mold growth. So care should be taken before chasing credits. (Odom & Scott et al., NCARB Monograph 2007 Vol. 10 issue 2)
Make sure you have a LEED accredited professional on your team to help with the process. Some firms provide LEED administrators as consultants to the design team. Note that the reference manuals and guides available for purchase by the USGBC are not updated with recent changes. Your team is expected to find new changes buried within the USGBC web site. It would help if mandatory changes were posted in a clear manner that could be found easily instead of being buried in their press releases. However anyone experienced with LEED should understand the process.
Other FAQs in our sustainable series: