July 30, 2011
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The pre drywall inspection is the first required site inspection in the LEED for Homes process. A green rater will need to visit the site to inspect the wall cavity. This step is crucial because once the drywall goes up it is impossible to inspect and verify many of the requirements for certification. This step must be completed and any home looking to pursue LEED certification must enroll before the drywall goes up to allow for this inspection. I recently helped with a pre drywall inspection on a building targeting LEED Platinum.
The inspection involves checking to make sure that the insulation is properly installed in the wall cavity. If it is batting insulation it must not be compressed or it won’t prevent air from moving and will perform poorly. Other insulation types should evenly fill the cavity. It is also important to check that the vapour barrier is in place and properly sealed. Any insulation problems that are identified during the inspection can be fixed before the drywall is applied.
It is also required that all ductwork be sealed to prevent contamination with construction debris. Ducts contaminated with dust and other debris will need to be cleaned, which is very difficult, or they will have adverse effects on the indoor air quality. Duct sealing is required by LEED and the pre drywall inspection will make sure that this step is completed.
Any LEED checklist items that are located behind the walls must also be verified at this time. For example, if the home was hoping to earn points for having pipes insulated this would have to be verified now, while the pipes are still visible.
The wall cavities need to be inspected before the drywall covers them up for good.
July 12, 2011
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I recently took part in a LEED for Homes preliminary evaluation. This is the first step in the LEED for Homes process and involves going through all of the requirements for LEED Certification before construction of the home starts. Starting the process early is key because it allows all parties involved to set clear goals and performance requirements. This is important because many LEED credits don’t add cost but they must be initiated early in the design process. LEED uses an Integrative Design Process which means all parties involved (owner, builder, architect, landscaper etc) collaborate throughout the process instead of working independently.
The categories for LEED for Homes are:
1) Sustainable Sites
2) Energy and Atmosphere
3) Material and Resources
4) Water Efficiency
5) Indoor Environmental Quality
6) Innovation in Design
7) Location and Linkages
8) Awareness and Education
The last two are LEED for Homes specific. Location and Linkages works to ensure that the home is located in a developed area within walking distance of amenities and public transportation. This helps prevent urban sprawl. Awareness and Education helps promote LEED for Homes by encouraging you to hold an open house for the community, as well as install LEED signage to highlight your recognition.
The project team goes through the LEED for Homes checklist and identifies what it is capable of achieving. The prerequisites are the most important part because the project cannot be certified without meeting these. In additional to specific prerequisites LEED for Homes also has minimum point thresholds in each of the categories. The team confirms it can meet the prerequisites and identifies which credits it can achieve and which ones it might be able to achieve. The spreadsheet tallies up the total credit points as well as the credit points that may be possible. Depending on how many points the team thinks they can obtain the project sets the target for Certified (Lowest), Silver Certified, Gold Certified, or Platinum Certified (Highest).
LEED for Homes contains a home size adjuster and is the only LEED program to contain such an adjustment. It is designed to reward those who build a smaller home instead of a larger one. The spreadsheet will use the size of the home and the number of bedrooms to calculate this adjustment and determine the point thresholds for each level of certification (Silver, Gold etc). Homes of the same size will do better if they have more bedrooms.
Finally an accountability form is filled out which identifies which member of the project team is responsible for which prerequisites or credits. This form will guide the team through the LEED for Homes process.
Did I mention that LEED for Homes is the only 3rd party verified rating system in the country for homes? For more information on the LEED for Homes rating system visit the Canadian Green Building Council.