Transcript Document
3
GREEN PRACTICES IN HOME CONSTRUCTION
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In This Chapter
Innovative methods and materials
Achieving energy efficiency
Factors for calculating cost/benefit
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Innovative Construction Methods and Materials
Modular building and panelized construction materials
Structural Insulated Panels (SIPs)
Precast Concrete Panels
Insulating Concrete Forms (ICFs)
Straw-Board Panels
Structural Insulated Panels (SIPs)
3-3 Source: Reprinted with permission of Structural Insulated Panel Association, www.sips.org
Precast Concrete Panels
3-4 Source: Reprinted with permission of NAHB Research Center’s Tool Base Services, www.toolbase.org
Straw-bale Homes
3-5 Source: Reprinted with permission of Tipping Mar & Associates, www.tippingmar.com
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Optimum Value Engineering (OVE)
Advanced framing technique that reduces lumber used for framing and creates more room for insulation in exterior walls
See Figure 3.4
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Energy Efficiency
Energy efficiency: Primary goal of green consumers
Energy model predicts how design for home or building performs against benchmark
Energy models may be conducted on-site or virtually
HERS Index
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Energy index begins in preconstruction phase
Certified rater evaluates design and construction plans using specialized software
Rater works with builder to optimize energy efficiency
Once home is complete, rater will conduct inspections and tests, including a blower door test and duct test, and give the home a HERS Index
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HERS Index
Benefits:
Obtaining a widely accepted rating Using rater who is qualified and certified Quantifying energy efficiency goals and verifying that they are met Qualifying for energy mortgage Qualifying for federal energy efficiency tax credits Meeting ENERGY STAR standards
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HERS Index
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Determining Energy Performance in Built Homes
Energy assessment: Identifies and predicts issues with energy performance using methods and tools
Energy survey: Easy do-it yourself tool that identifies energy efficiency issues and goals, as well as need for comprehensive energy diagnostics
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Hot Water Heaters
Technologies include:
Drain water heat recovery systems On-demand water-circulation pumps Tankless water heaters
Retrofitting, Remodeling, and Renovating Existing Homes
Retrofitting
– Lower-level upgrades to improve energy efficiency and IAQ, conserve resources, and meet other green goals
Remodeling
– Higher-level options that change appearance of home and have greater impact on energy efficiency, IAQ, and resource conservation
Renovating
– Installation of advanced systems that substantially change performance of home 3-13
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Challenges
Changing elements of building envelope: Impossible or cost prohibitive
Changing orientation of entire home: Often impossible
Installation of advanced systems: Cost-prohibitive
Challenges
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Clients often conflicted about whether keeping aspects or features in place is “more green” than gutting and replacing
Work must be scheduled according to health, comfort, and availability of clients and customers
Be wary of greenwashing when looking for quick retrofits
Remodeling and renovating must be sequenced according to client preferences
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Challenges
IAQ issues often arise
Integration of systems requires skill and innovation
Clients balancing priorities with budgetary considerations: Difficult
Zoning laws and building codes may limit options
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Cost/Benefit Analysis
Cost/benefit analysis of new construction is difficult
Depends on extent of project and value expectations of clients and customers
See charts in Figures 3.10-3.12 for payback times, cost savings, and ROI numbers for each option
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Exercise
Focuses on factors for calculating cost/benefit and identifying client and customer value perceptions
Read the scenario and answer the questions that follow.