Eco-efficiency analysis for green buildings

Abstract

The green building isa revolution in the construction industry in recent years. The concerns of green buildings are the environmental impacts and economic benefits to the human world. Eco-efficiency integrates the two concerns as one indicator to assess the greenness and economic efficiency for buildings. This research developed the eco-efficiency indicators for green buildings. Four environmental impacts are energy, water, waste and recycle and CO2 emissions. Four economic costs of design, construction, operation and green are the economic components. From analyzing the characteristics of buildings, three prominent indicators are determined: (1) construction cost/energy consumption, (2) operation cost/CO2 emissions, and (3) green cost/CO2 emissionsreduction. Eco-efficiency calculations were performed from the data of 9 LEED buildings. The first two indicators point out different strategy options for the ‘greenness” of buildings. For example, higher construction cost maybe for the platinum buildings resultin higher value of construction cost/energy;the lower operation costforagreener building brings smallervalue of operation cost/CO¬2. The values of eco-efficiency can be increased or decreased to mean better performance. In the third indicator, with lower green costs, the certified buildings have the best eco-efficiency in CO2 emissions reduction. Although the energy consumption and CO2 emissions of LEED gold buildings are smaller, the green cost of these buildings is much higher. Therefore, the gold building’s eco-efficiency is not better than those with lower certified levels.