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:
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.
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 vol.2.
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 naturally 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.
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 tipping fees. More and more firms now provide varying levels of off-site separation and recycling of materials commingled in dumpster at the construction site, easing the burden of providing dumpster space. King County provides assistance in recycling CDL waste.
Green Building Materials
Most green building benchmarking tools provide credits for reusing materials from other buildings, using building materials with recycled content, building materials manufactured locally and regionally with raw materials sourced locally and regionally, rapidly renewable materials and use of sustainably certified wood products. 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 informing subcontrators and suppliers of the intent of specifications. Developing a system to track and record all these materials and their origin early in a project will simplify checklist documentation requirements and insure that all green materials receive appropriate credit. Securing materials such as FSC (Forest Stewardship Council) at competitive prices requires advanced planning. Forest Products Solutions helps connect projects and contractors to forest product manufacturers and suppliers.
Construction Indoor Air Quality
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
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. A comprehensive listing of low-emitting materials, developed for schools by the Collaborative for High Performance Schools, is also appropriate for other building uses.
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