Water efficiency scenarios for green commercial buildings in Mexico and related CO2 emissions mitigation

This study evaluates green commercial building water efficiency opportunities in Mexico through three scenarios to estimate potential reductions in potable water consumption, energy consumption, and CO 2 emissions through the year 2050. The scenarios include (1) a baseline scenario where current water use rates remain static, (2) a scenario where new constructions adopt the 2010 California Green Building Standards Code (Calgreen), and (3) a scenario where new constructions adopt additional measures to Calgreen (CalgreenPlus). In 2050 water consumption in the commercial sector would reach about 4,099 million, 2,900 million, and 2,700 million m 3 in the baseline, Calgreen and CalgreenPlus scenarios, respectively.  Reductions reached are equivalent to about 100% of the current annual water consumption of Mexico City. Energy consumption related to water use is estimated to reach 7 TWh, 5 TWh, and 4.7 TWh, for the baseline, Calgreen, and CalgreenPlus scenarios, respectively. This represents a 29% and 32% energy consumption reduction in the saving scenarios compared to the baseline scenario. Emissions reductions of 1.3 million t carbon dioxide (tCO 2 ) and 1.4 million tCO 2 , as well as monetary savings equivalent to 44% and 50% of Mexico´s budget for higher education would be achieved from implementing the Calgreen and CalgreenPlus scenarios, respectively.