Sunday, November 22, 2009

LEED™ Green Building Rating System Explained

Humber Arboretum Centre for Urban Ecology, LEED GoldToronto, Ontario

Source: http://www.enermodal.com/Canadian/leed_explained.html

The LEED (Leadership in Energy and Environmental Design) green building rating system was originally developed by the US Green Building Council (USGBC) to provide a recognized standard for the construction industry to assess the environmental sustainability of building designs. Canadian Green Building Council (CaGBC) has since adapted the USGBC LEED rating system to the specific concerns and requirements of buildings in Canada.
LEED is a point-based rating system; points are earned for building attributes considered environmentally beneficial. LEED differs from other rating systems in that it has quantified most of the "green credits." For example, 5% of the building materials must be from salvaged materials to earn a point for the salvaged materials credit.

LEED has 69 points (70 for LEED Canada) covering six topic areas. Each topic area has a statement of associated goals.
  • Site Development: minimize storm water run-off, encourage car pooling and bicycling, increase urban density and green space
  • Water Efficiency: eliminate site irrigation, reduce water consumption, minimize or treat wastewater
  • Energy Efficiency: reduce building energy consumption, use renewable energy, eliminate ozone-depleting chemicals, commission building systems
  • Material Selection: minimize construction waste, re-use existing building façade, use recycled and salvaged materials, use renewable construction materials and design and build more durable buildings
  • Indoor Environmental Quality: incorporate daylighting, use low off-emitting materials, provide operable windows and occupant control of work space, improve delivery of ventilation air
  • Innovation in Design: use a LEED Accredited Professional, greatly exceed the requirements of a credit, incorporate innovative environmental features not covered in other areas, develop a green education plan (such as installing an Enermodal Signature Green Building Kiosk)
Designers can pick and choose the credits most appropriate to their project to achieve a rating. LEED has four performance ratings:
26 to 32 points: Certified
33 to 38 points: Silver
39 to 51 points: Gold
52 or more points: Platinum




In addition to different levels of achievement, there are different types of certification. Besides the traditional LEED-NC (New Construction), there is LEED-EBOM (Existing Buildings), LEED-ND (Neighbourhood Development), LEED-CI (Commercial Interiors), and LEED-CS (Core and Shell).
The LEED system can be used in three ways to improve the “green-ness” of a building design:
  1. LEED can serve as a design guide for the design team. The LEED credit system is a systematic way of ensuring that the most important environmental issues are considered during the design of a building.
  2. LEED reports are a valuable means of showing the client and other interested parties that the design has effectively addressed environmental issues.
  3. A building design can be certified by the USGBC or CaGBC.
Certification provides increased market exposure and places the building in elite company among the most green buildings in North America. LEED registration and certification fees are 4 cents US or 7 cents CDN per square foot. In addition, LEED requires calculations and documentation to validate each credit claimed.
LEED is the most recognized green building rating system in North America. There are about 1,000 buildings that have been registered with the CaGBC. Many developers, particularly those working on federal government and leading-edge private sector buildigs, are requiring that building designs meet LEED Silver performance. Given that conventional new buildings would likely score only a few LEED points, achievement of any LEED level represents a significant reduction in building environmental impact and improvement of indoor environment.
The Canadian version of LEED is similar to the US version with the exception that energy efficiency is relative to the Canadian Model Energy Code for Buildings.
The larger benefit of LEED buildings is an improved indoor environment (lower absenteeism, greater productivity, better thermal comfort), lower maintenance costs (commissioned building, more durable materials, smaller or eliminated building systems), higher corporate profile (increased product sales, marketing advantage, improved employee morale), and reduced risk of remedial measures (to deal with sick building syndrome or environmental contaminants). The table below summarizes typical costs and payback periods for LEED buildings. The payback includes only annual utility energy savings.
LEED Rating
Certified
Silver
Gold
Platinum
LEED Points
26 to 32
33 to 38
39 to 51
52 to 69
Energy Savings
25 to 35%
35 to 50%
50 to 60%
>60%
Annual Utility Savings
$0.75/ft2
$1.00/ft2
$1.25/ft2
$1.50/ft2
Typical Payback
Under 3 yrs
3-5 yrs
5-10 yrs
10+ years
Incremental Construction Cost
Small Buildings
3%
7%
10%
15%
Large Buildings
1%
3%
5%
8%

Enermodal Services

Enermodal is one of Canada’s premier sustainability consultants, with staff members who were Ontario’s first LEED APs. Our staff includes LEED Faculty members and members of LEED advisory groups. We are currently working on over 180 LEED building projects worth over $4 billion and have certified more buildings in Canada than any other firm.Enermodal can lead the design teams through the LEED process and provide insight on how other green projects meet the requirements of each credit. As LEED APs, Enermodal staff can evalute which credits the design has met and issue a LEED Assessment Report outlining the level achieved. Finally, Enermodal can develop the application package for submission to the CaGBC and provide the necessary expertise to ensure the project receives the designation it is entitled.

I found this article very interesting, because they explain a little bit better ( in the table) how the LEED works in a matter of Energy saving related with the labels (Gold, Platinum, etc).

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