How Effective Are Building Codes at Reducing Residential Water Use? Evidence From California Billing Data

• 成果类型: Article
• 署名作者: Nemati, Mehdi
• 署名单位: University of California System; University of California Riverside
• 刊物名称: JOURNAL OF POLICY ANALYSIS AND MANAGEMENT
• ISSN/ISSBN: 1520-6688
• DOI: 10.1002/pam.70089
• 发表日期: 2026-02-15
• 页码: e70089
• 关键词: BUILDING CODES; CALGreen; cost-effectiveness analysis; residential water conservation; LANDSCAPE IRRIGATION; demand; energy; management; cost

摘要

This study examines the impact of residential water-efficiency standards on household water consumption, utilizing billing data from California. I examine both the short- and long-term impacts of the California Green Building Standards Code (CALGreen), comparing homes constructed just before and after its implementation in 2010. The findings show that, on average, CALGreen homes use 11.7% less water than comparable pre-code homes, with savings persisting over time at approximately 10.9%. Notably, engineering-based (ex ante) estimates of water savings are nearly twice as large as the realized reductions, likely reflecting the offsetting behavior effect. The analysis further reveals that most water savings occur during warmer months when outdoor water use peaks. In addition, CALGreen homes exhibit lower sensitivity to temperature fluctuations, with smaller increases in use during hotter months and smaller reductions during cooler months. Finally, when accounting for compliance costs and the opportunity cost of water, the results suggest that CALGreen policy passes a cost-effectiveness test. These findings highlight the effectiveness of building codes as a durable policy tool for achieving long-term water conservation in fast-growing, semi-arid regions.