DEQ LCA Report

Prioritizing Green Building and Waste Prevention Practices with Life Cycle Assessment: Systems Thinking for Residential Buildings

This report for the Oregon Department of Environmental Quality, conducted by Earth Advantage Institute, Quantis and the Oregon Home Builders Association, identifies green building practices that should be prioritized based on the greatest benefits provided over the life cycle of residential homes in Oregon.  The research examined the effects on life cycle impact of over 20 distinct green building practices ranging from design issues, construction techniques and material selections, such as advanced framing techniques, multi-story housing, utilization of durable materials, and placing ducts in conditioned space, among others.

Key Findings

• The majority of impacts occur during occupancy, and 85% of the impact is in energy use by occupants. Materials represent only 14% of life cycle GHG impacts.
• Of the 30 different material reduction and reuse practices evaluated, reducing home size and multi-family living achieved the largest greenhouse gas reductions along with significant reductions in other impact categories.
• Reducing home size by 50 percent (from approximately 2200 square feet to 1100 square feet) results in a projected 36 percent reduction in lifecycle greenhouse gas emissions.
• Reducing home size is a significant leverage point for environmental impact reduction and may be and may be equivalent to achieving minimum levels of “green” certification.
• Various sizes of multi-family housing show significant lifecycle reductions in greenhouse gases and most other pollutants.
• Families who choose or require more living space than a “small” home may lessen a large home’s impact by adding green building practices and increasing the home’s energy efficiency.

Reports

• Full Report -- Residential Buildings: An Evaluation of Waste Prevention Practices Using Lifecycle Analysis
• Executive Summary -- Residential Buildings: An Evaluation of Waste Prevention Practices Using Lifecycle Analysis
• Appendix 17