title: Environmental Impact of Buildings--What Matters?
abstract: The goal of this study was to identify drivers of environmental impact and quantify their influence on the environmental performance of wooden and massive residential and office buildings. We performed a life cycle assessment and used thermal simulation to quantify operational energy demand and to account for differences in thermal inertia of building mass. Twenty-eight input parameters, affecting operation, design, material, and exogenic building properties were sampled in a Monte Carlo analysis. To determine sensitivity, we calculated the correlation between each parameter and the resulting life cycle inventory and impact assessment scores. Parameters affecting operational energy demand and energy conversion are the most influential for the building's total environmental performance. For climate change, electricity mix, ventilation rate, heating system, and construction material rank the highest. Thermal inertia results in an average 2-6% difference in heat demand. Nonrenewable cumulative energy demand of wooden buildings is 18% lower, compared to a massive variant. Total cumulative energy demand is comparable. The median climate change impact is 25% lower, including end-of-life material credits and 22% lower, when credits are excluded. The findings are valid for small offices and residential buildings in Switzerland and regions with similar building culture, construction material production, and climate.
authors.affiliation: †Institute of Environmental Engineering, Chair of Ecological System Design, ETH Zurich, John-von-Neumann-Weg 9, 8093 Zurich, Switzerland.
authors.forename: Niko
authors.initials: N
authors.lastname: Heeren
authors.affiliation: ‡Technology Assessment Group (LEA), Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Mutel
authors.affiliation: †Institute of Environmental Engineering, Chair of Ecological System Design, ETH Zurich, John-von-Neumann-Weg 9, 8093 Zurich, Switzerland.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Steubing
authors.affiliation: §Department of Civil and Environmental Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
authors.forename: York
authors.initials: Y
authors.lastname: Ostermeyer
authors.affiliation: §Department of Civil and Environmental Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
authors.forename: Holger
authors.initials: H
authors.lastname: Wallbaum
authors.affiliation: †Institute of Environmental Engineering, Chair of Ecological System Design, ETH Zurich, John-von-Neumann-Weg 9, 8093 Zurich, Switzerland.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hellweg
mesh_terms: D003252:Construction Materials; D004777:Environment; D006798:Housing; D008962:Models, Theoretical; D013557:Switzerland; D013816:Thermodynamics; D014934:Wood