Electronic Supplementary Material

Table S1 Inventory data for the glulam beam and steel frame product systems (LCI refers to life cycle inventory)

Processes / Amount / Unit / Reference and technical details
Glulam beam product system
Reference flow: glulam beam / 1280 / kg / Personal communication with Mats Axelsson, SP Technical Research Institute of Sweden, February 2012
Glulam beam manufacturing / Puettmann et al. (2013)
Sawn softwood timber, rough, kiln dried / 959 / kg / LCI dataset: “RER: sawn timber, softwood, raw, plant-debarked, u=70%, at plant” (Ecoinvent 2013)
Sawn softwood timber, rough, green / 322 / kg / LCI dataset: “RER: sawn timber, softwood, raw kiln dried, u=10%, at plant” (Ecoinvent 2013)
Liquefied petroleum gas / 3.50 / L / LCI dataset: “CH: liquefied petroleum gas, at service station” (Ecoinvent 2013)
Gasoline / 46.2 / L / LCI dataset: “EU-27: Gasoline mix (regular) at refinery PE” (PE International 2013)
Diesel / 0.95 / L / LCI dataset: “RER: diesel, at regional storage” (Ecoinvent 2013)
Glue (PVAc) / 21.4 / kg / LCI dataset: “PVAc” (Personal communication with Johan Widheden, AkzoNobel October 2010)
Natural gas / 10.5 / m3 / LCI dataset: “RER: natural gas, burned in boiler condensing modulating >100 kW” (Ecoinvent 2013)
Electricity (continental European mix) / 183 / kWh / LCI dataset: “UCTE: electricity, production mix UCTE” (PE International 2013)
Wood fuel / 49.7 / kg / LCI dataset: “CH: heat, softwood, chips from industry, at furnace 200 kW” (Ecoinvent 2013)
Packaging in transportation / 8.34 / kg / Carling (2008)
Polyethylene / LCI dataset: “RER: polyethylene, HDPE, granulate, at plant” (Ecoinvent 2013)
Demolition (diesel or wind) / 225 / MJ / Winistorfer et al. (2012), using mass to allocate energy to the glulam beam
Diesel / LCI dataset: “GLO: diesel, burned in building machine” (Ecoinvent 2013)
Wind power / LCI dataset: “RER: electricity, at wind power plant” (Ecoinvent 2013)
Disposal by municipal incineration (by-product: heat; substitutes natural gas or municipal biowaste) / 20480 / MJ / Carling (2008), assuming a heat value of 16 MJ/kg and a 20% moisture ratio
Municipal incineration / LCI dataset: “CH: disposal, building, waste wood, untreated, to final disposal” (Ecoinvent 2013)
Natural gas / LCI dataset: “RER: natural gas, burned in boiler condensing modulating >100 kW” (Ecoinvent 2013)
Biowaste / LCI dataset: “CH: heat, biowaste, at waste incineration plant, future, allocation price”
Disposal by recycling (by product: wood; substitutes debarked round wood) / 1280 / kg
Debarked round wood / LCI dataset: “RER: round wood, softwood, debarked, u=70% at forest road”
Steel frame product system
Reference flow: steel frame / 1270 / kg / Personal communication with Mats Axelsson, SP Technical Research Institute of Sweden, February 2012
Steel frame manufacturing / Björklund et al. (1996)
Electricity / 2540 / MJ / LCI dataset: LCI dataset: “UCTE: electricity, production mix UCTE” (PE International 2013)
Steel (low-alloyed) / 1270 / kg / LCI dataset: “RER: steel, low-alloyed, at plan” (Ecoinvent 2013)
Demolition; energy / 229 / MJ / Winistorfer et al. (2012), using mass to allocate energy to the steel frame
Diesel / LCI dataset: “GLO: diesel, burned in building machine” (Ecoinvent 2013)
Wind power / LCI dataset: “LCI dataset: “RER: electricity, at wind power plant” (Ecoinvent 2013)
Disposal by recycling (by product: steel; substitutes average low-alloyed steel or recycled un- and low-alloyed steel) / 1270 / kg
Steel (low-alloyed) / LCI dataset: “RER: steel, low-alloyed, at plan” (Ecoinvent 2013)
Steel (recycled, un- and low-alloyed) / LCI dataset: “RER: steel, electric, un- and low-alloyed, at plant” (Ecoinvent 2013)
Processes common for both product systems
Transportation of input materials / 200 / km / Estimate
20-28 t lorry (fleet average) / LCI dataset: “CH: transport, lorry 20-28t, fleet average” (Ecoinvent 2013)
Transportation to building site / 500 / km / Estimate
20-28 t lorry (fleet average) / LCI dataset: “CH: transport, lorry 20-28t, fleet average” (Ecoinvent 2013)
Transportation to disposal site / 50 / km / Estimate
20-28 t lorry (fleet average) / LCI dataset: “CH: transport, lorry 20-28t, fleet average” (Ecoinvent 2013)
20-28 t lorry (RME) / LCI dataset: “CH: transport, lorry 28t, rape methyl ester 100%” (Ecoinvent 2013)

Table S2 Impact assessment results for the glulam beam and steel frame product systems. Results are given as net impact of the full life cycles and as impact of EoL processes.

Scenarios / GWP
(kg CO2 eq./FU) / EP
(kg PO4-3 eq./FU) / POCP
(kg ethylene eq./FU) / Water depletion potential
(m3 water/FU) / Primary energy (total)
(MJ/FU) / Primary energy (fossil)
(MJ/FU)
Glulam beam product system
GreyIncCut / Net / 2.74E+02 / 1.70E+00 / 1.18E+00 / 1.88E+03 / 4.12E+04 / 1.24E+04
EoL / 1.92E+03 / 4.49E-01 / 9.3E-02 / 4.64E+01 / 7.27E+02 / 7.19E+02
GreyIncSub / Net / -1.10E+03 / 1.52E+00 / 9.43E-01 / 1.73E+03 / 1.96E+04 / -9.22E+03
EoL / 5.47E+02 / 2.75E-01 / -1.42E-01 / -1.05E+02 / -2.10E+04 / -2.09E+04
GreenIncCut / Net / 1.28E+02 / 1.50E+00 / 1.04E+00 / 1.77E+03 / 3.99E+04 / 1.01E+04
EoL / 1.90E+03 / 4.59E-01 / 6.8E-02 / 7.37E+01 / 1.41E+03 / 3.86E+02
GreenIncSub / Net / 1.14E+02 / 5.50E-01 / 9.23E-01 / 1.67E+03 / 4.02E+04 / 1.04E+04
EoL / 1.76E+03 / -6.98E-01 / -1.62E-01 / -1.61E+02 / -3.22E+02 / -1.31E+03
GreyReCut / Net / -1.61E+03 / 1.31E+00 / 1.12E+00 / 1.86E+03 / 4.10E+04 / 1.22E+04
EoL / 3.30E+01 / 6.40E-02 / 3.5E-02 / 2.10E+01 / 4.90E+02 / 4.87E+02
GreyReSub / Net / 3.41E+02 / 1.23E+00 / 8.77E-01 / 1.82E+03 / 1.80E+04 / 1.16E+04
EoL / 1.99E+03 / -1.70E-02 / -2.09E-01 / -1.39E+01 / -2.25E+04 / -1.04E+02
GreenReCut / Net / -1.63E+03 / 1.32E+00 / 1.10E+00 / 1.88E+03 / 4.17E+04 / 1.66E+04
EoL / 1.15E+01 / 7.4E-02 / 1E-02 / 4.83E+01 / 1.18E+03 / 1.54E+02
GreenReSub / Net / 3.20E+02 / 1.24E+00 / 8.52E-01 / 1.85E+03 / 1.87E+04 / 1.12E+04
EoL / 1.96E+03 / -7E-03 / -2.33E-01 / 1.33E+01 / -2.18E+04 / -4.37E+02
NoEoL / Net / -1.64E+03 / 1.25E+00 / 1.09E+00 / 1.83E+03 / 4.05E+04 / 1.17E+04
EoL / 0.00E+00 / 0.00E+00 / 0.00E+00 / 0 .00E+00 / 0 .00E+00 / 0.00E+00
Steel frame product system
GreyReCut / Net / 2.74E+03 / 6.77E+00 / 1.95E+00 / 1.93E+04 / 4.46E+04 / 4.22E+04
EoL / 3.33E+01 / 6.5E-02 / 3.6E-02 / 2.10E+01 / 4.94E+02 / 4.91E+02
GreyReSub / Net / 5.69E+02 / 1.57E+00 / 2.99E-01 / 2.90E+03 / 1.08E+04 / 1.03E+04
EoL / -2.14E+03 / -5.13E+00 / -1.61E+00 / -1.64E+04 / -3.33E+04 / -3.14E+04
GreenReCut / Net / 2.71E+03 / 6.71E+00 / 1.92E+00 / 1.93E+04 / 4.50E+04 / 4.18E+04
EoL / 2.70E+00 / 7E-03 / 2E-03 / 2.24E+01 / 9.30E+02 / 3.85E+01
GreenReSub / Net / 2.18E+03 / 5.13E+00 / 1.61E+00 / 1.64E+04 / 3.43E+04 / 3.15E+04
EoL / -5.31E+02 / -1.57E+00 / -3.03E-01 / -2.83E+03 / -9.83E+03 / -1.02E+04
NoEoL / Net / 2.71E+03 / 6.7E+00 / 1.91E+00 / 1.93E+04 / 4.41E+04 / 4.17E+04
EoL / 0.00E+00 / 0.00E+00 / 0.00E+00 / 0.00E+00 / 0.00E+00 / 0.00E+00

References

Björklund T, Jönsson Å, Tillman A-M (1996) LCA of Building Frame Structures: Environmental Impact over the Life Cycle of Concrete and Steel Frames. Technical Environmental Planning Report 1996:8, Chalmers University of Technology, Gothenburg, Sweden

Carling O (2008) Limträ: handbok (English: “Glulam: handbook”). Print and Media Center i Sundsvall AB, Sundsvall, Sweden. http://www.svensktlimtra.se/Upload/File/publikationer/2009/Limtrahandbok_200812.pdf. Accessed 7 March 2012

Ecoinvent (2013) Database ecoinvent data v2.2, Swiss Centre for Life Cycle Inventories. http://www.ecoinvent.ch. Accessed February 2013

PE International (2013) GaBi Professional database. http://www.pe-international.com. Accessed February 2013

Winistorfer P, Chen Z, Lippke B, Stevens N (2005) Energy consumption and green house emissions related to the use, maintenance and disposal of a residential structure, Final Report. http://www.corrim.org/pubs/reports/2005/Phase1/Module_KLM_Final.pdf. Accessed 5 October 2012

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