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Saving Energy versus Saving Materials
Author(s) -
Nishioka Yurika,
Yanagisawa Yukio,
Spengler John D.
Publication year - 2000
Publication title -
journal of industrial ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.377
H-Index - 102
eISSN - 1530-9290
pISSN - 1088-1980
DOI - 10.1162/108819800569212
Subject(s) - energy consumption , life cycle assessment , environmental science , consumption (sociology) , production (economics) , greenhouse gas , energy intensity , material flow analysis , total energy , waste management , engineering , economics , psychology , ecology , social science , displacement (psychology) , sociology , biology , electrical engineering , psychotherapist , macroeconomics
Summary To reduce energy consumption and carbon dioxide (CO 2 ) emissions in housing construction, the energy‐intensive processes and life‐cycle stages should be identified and integrated. The environmental impact of vertically integrated factory‐built homes (VIHs) constructed with increased material inputs in Japan's northern island of Hokkaido was assessed using life‐cycle inventory (LCI) analysis methods. Manufacturing process energy and CO 2 intensities of the homes were evaluated based on the material inputs. They were compared with those of a counterpart home hypothetically built using the vertically integrated construction methods, but in accordance with the specifications of a less material‐intensive conventional home (CH) in Hokkaido today. Cumulative household energy consumption and CO 2 emissions were evaluated and compared with those of the production stages. The annual household energy consumption was compared among a VIH, a CH, and an average home in Hokkaido. The energy intensity of the VIH was 3.9 GJ production energy per m 2 of floor area, 59% higher than that of the CH. Net CO 2 emissions during VIH manufacturing processes were 293 kg/m 2 , after discounting the carbon fixation during tree growth. The cumulative use‐phase household energy consumption and CO 2 emissions of a VIH will exceed energy consumption and CO 2 emissions during the initial production stage in less than six years. Although VIHs housed 21% more residents on average, the energy consumption per m2 was 17% lower than that of a CH. This may indicate that using more materials initially can lead to better energy efficiency.