City Green Building
Recommended Construction Practices

The most successful projects not only develop green building strategies during early design stages, they also implement them well during construction.  The contractor is a key player with:

Early Involvement
Contractors often play the role of value engineer, participating as a member of the design team by analyzing costs, constructability and ease of eventual O&M for alternative solutions investigated.  While this may add a little time to schematic design and design development stages, it also avoids cost surprises during bidding and negotiation that can cause serious re-design and even elimination of beneficial sustainable building strategies, thus saving time in later stages.

Early involvement also provides the contractor with a clearer understanding of the owner’s goals and the designer’s intent, which facilitates execution of the contract documents.  City projects may enter into a General Contractor/Construction Management (GC/CM) contact with City Council approval to bring the contractor on early. 

Protecting the Site
Seattle’s code relating to surface water quality protection during construction is very proactive.  Make sure your project follows both the intent and best management practices required in the code.  For details, see the Construction Stormwater Control Technical Requirements Manual.

Much of the natural quality of previously undeveloped or partially developed sites can be maintained by careful staging of construction, staging of equipment and material storage areas, and by selecting the right equipment to use for site work.  Stripping and storing top soil for reuse allows a site to be revegetated more quickly and require fewer soil amendments and less early maintenance.  Selecting the right heavy equipment for site work, excavation and utility installation can reduce disturbance to the site and existing vegetation.

Commissioning
Historically commissioning was “balancing and tuning” of HVAC&R mechanical systems, performed by either the general contractor or mechanical contractor or both.  Experience with complex mechanical systems used today has shown that third party commissioning can insure that those systems are performing optimally when the building is turned over to the owner and his facility managers.  A well executed commissioning plan, whether required or optional, helps educate the facility managers of how the system operates and is supposed to operate, shortening their learning curve and allowing them to keep the building systems operating at peak performance from initial building occupancy.

The contractor plays a key role by understanding commissioning requirements and scheduling commissioning services.  The Building Commissioning Association provides resources on commissioning and certification of commissioning agents.

Construction Waste Management
One of the biggest impacts of construction can be disposal of construction, demolition and land clearing (CDL) wastes from a site.  Many of these materials, whether materials of buildings removed from a site, or materials removed during excavation, can be recycled and used again, reducing the impact on municipal landfills.

Many contractors are finding that it is less expensive to sort and store CDL wastes on site for recycling, even on tight urban sites, than to pay the cost of disposal fees.  King County provides assistance in recycling CDL waste.

If demolition is a component of your project, the Northwest Building Salvage Network’s website lists companies in Seattle that may take salvaged building materials.

Green Building Materials
LEED provides credits for: incorporating salvaged building materials into your project, using building materials with recycled content, purchasing building materials manufactured locally and regionally with raw materials sourced locally and regionally, installing rapidly renewable materials, and sourcing wood products certified by the Forest Stewardship Council (FSC).  All these strategies reduce off-site environmental impacts and energy used for both fabrication and transport.

The contractor plays a pivotal role by carefully following project material specifications, suggesting better alternatives, and holding subcontrators and suppliers accountable for meeting product specifications.  An experienced contractor will have a system to track and record all these materials and their origin to meet documentation requirements and insure that all green materials receive appropriate credit. 

Construction Indoor Air Quality
Ensuring proper ventilation during construction, maintaining low moisture levels and sealing air distribution systems to avoid contamination help protect a home’s indoor environment down the road. The Greater Vancouver Regional District has resources to help.

Many of the attributes of the final indoor air quality of a finished building depend on developing indoor air quality management plans for storing and installing building materials on site.  The Sheet Metal and Air Conditioning Contractors National Association provides IAQ Guidelines for dealing with the indoor air quality related health impact on building occupants during building demolition, renovation or construction.  Developing a recording plan of the implementation of an indoor air quality management plan will simplify later documentation requirements.

Getting rid of the “new building” smell that results from building materials that off gas provides tenants with a high level of indoor air quality when the first occupy a building.  Either the building can be flushed out prior to occupancy by running the mechanical system to provide continuous outdoor air to remove contaminates or the building can be tested consistent with EPA standards. View EPA resources on indoor air quality

Low Emitting Materials
The use of low emitting materials – sealants, paints, primers, carpets and composite wood products – can avoid the contamination of air in new construction.  More and more materials are being manufactured that meet low VOC limits.  Many are cost competitive with standard materials.  It is critical for the contractor to be aware of specification of these materials, inform subcontractors and suppliers and monitor the use of low emitting materials and any proposed substitutions. 

See City of Seattle policy for paints.

Additional Resources

 

Last Updated: May 31, 2006