Environmental Impacts of Multi-Storey Buildings Using Different ...
Environmental Impacts of Multi-Storey Buildings Using Different ... Environmental Impacts of Multi-Storey Buildings Using Different ...
- 106 -9.2 Multi-Storey Timber BuildingsIt is acknowledged that, at present, no multi-storey timber buildings with the design andstructural engineering proposed for the Timber and TimberPlus buildings have been builtanywhere around the world. However, all the research results to date go well beyond initialexpectations and support the proposition that traditional concrete or steel multi-storeybuilding designs could instead be constructed with timber structural elements andarchitecture, utilising considerably more timber materials and components.This considerable body of research is now moving beyond the laboratory and into thecommercial building industry. The Foundation for Science, Research and Technology(FRST) – a NZ Government funded research body – has approved the establishment of a newresearch consortium which has formed a company, the Structural Timber InnovationCompany (STIC) to continue and expand research and commercialise the research output.The consortium is joined by many of the major timber producing and manufacturingcompanies in NZ and Australia who are providing joint funding over an initial five yearperiod. This collaborative Consortium can itself be viewed as a major achievement inbringing together national and international companies and industry bodies (more normallyused to competing with each other), producer associations and research establishments, manyof which have traditionally not worked closely together, to work towards a common goal.The success of securing substantial research funding both from the NZ Government andindustry, ultimately with the aim of constructing timber buildings similar to the timberdesigns considered by this research, is extremely encouraging. The ideas of the researchscientists are about to be put to the test in the real world of the hugely competitive,commercial building industry.9.3 Operational EnergyA vital phase of the energy analysis and modelling objective (Objective 2), and integral to theoverall research design, was the provision of alternative building designs which would allhave very similar operational energy consumption.The research demonstrates that each building easily meets the standards for being a lowenergy building, as well as achieving operational energy consumption for each buildingwithin 3% of each other.The very fact that this research demanded that the buildings needed to be designed withsimilar operational energy usage, provided constraints on the designs. In a ‘real’ building,design would be a trade-off between many factors and engineering design, the building’sthermal envelope, the building’s services (heating, cooling and ventilation) and other internalenergy demands (such as lighting) would be heavily influenced by the building’s location(geography), usage and, very importantly, by cost. This study was constrained by the designsbeing suited to a Christchurch location; however, the cost incurred in modifying designs(materials, etc.) to provide similar operational energy usage was not a determining factor.In the thesis, The influence of construction materials on life-cycle energy use and carbondioxide emissions of medium size commercial buildings, Perez (2008) notes that;
- 107 -• The buildings tend to be ‘internal load-dominated’ and their operational energy is lessdependent on the thermal characteristic of the building.• Even lower operational energy consumption could be achieved depending on theamount of insulation and thermal mass in each building.• Thermal mass in the Timber buildings (and indeed, in the Steel building) could beprovided through using more wood (as thermal mass) and also presents the future –and interesting - possibility of using Phase Change Materials.• For any two buildings with the same total operational energy consumption, the relativeamount of heating and cooling energy consumption may be very different dependingon the thermal envelope and the amount of thermal mass in each building.• For the low energy consumption buildings in this study, only 25% of the energyconsumption is in heating and cooling; 75% is for lighting, room electricity,miscellaneous systems and domestic hot water.Previous attempts to compare lifetime energy consumption and GWP of buildings have beenhampered by building design – not only has the operational energy of the building been verysignificant but it has also differed between buildings being studied. Hence, the significance ofembodied energy and other stages in the life cycle have been harder to determine and anydifferences in embodied energy have been over-ridden by differences in operational energy.This research has largely eliminated the operational energy variable and has allowed theimportance of other energy phases during the lifetime of the buildings – initial embodiedenergy, maintenance energy, transport and end-of-life –to be identified.It should be noted that providing buildings, as above, with similar operational energy was atime consuming task, requiring numerous ‘iterative’ designs where materials were changed,the design ‘tweaked’ and then the energy modelling was re-run. This would normally be avery expensive procedure.The operational energy design and analysis part of this research report was entirelysatisfactory and met Objective 2.9.4 The DataLife cycle assessment is entirely dependent on the data used at various stages in the analysis.The LCA process builds on data provided at a number of points during the analysis. Thequality of the data will largely determine the quality of any LCA study. The data - andassociated calculations – should be clearly presented, consistent and verifiable and anycalculations should be able to be reproduced.9.4.1 Operational EnergyPerez (2008) details all the data - and assumptions - on which the energy modelling for thefour alternative buildings is based. The Wellington based company e-Cubed Building
- Page 55 and 56: - 55 -6.3.2.2 System BoundariesThe
- Page 57 and 58: - 57 -For more information see:http
- Page 59 and 60: - 59 -6.3.3 Inventory Analysis6.3.3
- Page 61 and 62: - 61 -Table 6.2: Net tonnes CO 2 eq
- Page 63 and 64: - 63 -Growing timber takes up CO 2
- Page 65 and 66: - 65 -6.3.4 Impact AssessmentTotal
- Page 67 and 68: - 67 -8000700060005000GWP (t CO2 eq
- Page 69 and 70: - 69 -As explained above, carbon st
- Page 71 and 72: - 71 -Figure 6.10: Total embodied e
- Page 73 and 74: - 73 -Table 6.9: Total GWP of each
- Page 75 and 76: - 75 -8,0007,0006,0005,000GWP (t CO
- Page 77 and 78: - 77 -45000400003500030000GWP (kg C
- Page 79 and 80: - 79 -assumed to be identical for t
- Page 81 and 82: - 81 -6.4.3.2 Green Star Recycling
- Page 83 and 84: - 83 -Table 6.16: Green Star result
- Page 85 and 86: - 85 -The contribution of initial e
- Page 87 and 88: - 87 -results, the reutilisation sc
- Page 89 and 90: - 89 -7.1.1 Platform and Balloon Co
- Page 91 and 92: - 91 -buildings has been analysed a
- Page 93 and 94: - 93 -Figure 7.5: Construction sche
- Page 95 and 96: - 95 -8.2 Source and Availability o
- Page 97 and 98: - 97 -It would be incorrect, howeve
- Page 99 and 100: - 99 -8.5 Additional Opportunities
- Page 101 and 102: - 101 -example, removal of CCA trea
- Page 103 and 104: - 103 -The Waste Minimisation Bill
- Page 105: - 105 -9 Discussion9.1 The Building
- Page 109 and 110: - 109 -9.4.3 Data Sets9.4.3.1 Gener
- Page 111 and 112: - 111 -The following assessment wil
- Page 113 and 114: - 113 -Table 9.1. GWP coefficients
- Page 115 and 116: - 115 -Figure 9.2 shows that the ne
- Page 117 and 118: - 117 -placing and retaining materi
- Page 119 and 120: - 119 -Net CO 2 emissions - that is
- Page 121 and 122: - 121 -The LVL specified for the st
- Page 123 and 124: - 123 -10 ConclusionsThe following
- Page 125 and 126: - 125 -building types, instead subs
- Page 127 and 128: - 127 -In summary, reutilisation sh
- Page 129 and 130: - 129 -• What is the ranking of t
- Page 131 and 132: - 131 -• What is the comparison i
- Page 133 and 134: - 133 -Connell Wagner (2007): Combu
- Page 135 and 136: - 135 -Suzuki, Michiya, and Tatsuo
- Page 137 and 138: - 137 -C O N C R E T E B U I L D I
- Page 139 and 140: - 139 -S T E E L B U I L D I N Gm m
- Page 141 and 142: - 141 -T I M B E R B U I L D I N Gm
- Page 143 and 144: - 143 -T I M B E R B U I L D I N G
- Page 145 and 146: - 145 -T Exterior Wall Cladding 581
- Page 147 and 148: - 147 -Appendix B. Life times of bu
- Page 149 and 150: - 149 -Appendix D: Transport scenar
- Page 154 and 155: - 151 -Appendix F: Warren and Mahon
- 107 -• The buildings tend to be ‘internal load-dominated’ and their operational energy is lessdependent on the thermal characteristic <strong>of</strong> the building.• Even lower operational energy consumption could be achieved depending on theamount <strong>of</strong> insulation and thermal mass in each building.• Thermal mass in the Timber buildings (and indeed, in the Steel building) could beprovided through using more wood (as thermal mass) and also presents the future –and interesting - possibility <strong>of</strong> using Phase Change Materials.• For any two buildings with the same total operational energy consumption, the relativeamount <strong>of</strong> heating and cooling energy consumption may be very different dependingon the thermal envelope and the amount <strong>of</strong> thermal mass in each building.• For the low energy consumption buildings in this study, only 25% <strong>of</strong> the energyconsumption is in heating and cooling; 75% is for lighting, room electricity,miscellaneous systems and domestic hot water.Previous attempts to compare lifetime energy consumption and GWP <strong>of</strong> buildings have beenhampered by building design – not only has the operational energy <strong>of</strong> the building been verysignificant but it has also differed between buildings being studied. Hence, the significance <strong>of</strong>embodied energy and other stages in the life cycle have been harder to determine and anydifferences in embodied energy have been over-ridden by differences in operational energy.This research has largely eliminated the operational energy variable and has allowed theimportance <strong>of</strong> other energy phases during the lifetime <strong>of</strong> the buildings – initial embodiedenergy, maintenance energy, transport and end-<strong>of</strong>-life –to be identified.It should be noted that providing buildings, as above, with similar operational energy was atime consuming task, requiring numerous ‘iterative’ designs where materials were changed,the design ‘tweaked’ and then the energy modelling was re-run. This would normally be avery expensive procedure.The operational energy design and analysis part <strong>of</strong> this research report was entirelysatisfactory and met Objective 2.9.4 The DataLife cycle assessment is entirely dependent on the data used at various stages in the analysis.The LCA process builds on data provided at a number <strong>of</strong> points during the analysis. Thequality <strong>of</strong> the data will largely determine the quality <strong>of</strong> any LCA study. The data - andassociated calculations – should be clearly presented, consistent and verifiable and anycalculations should be able to be reproduced.9.4.1 Operational EnergyPerez (2008) details all the data - and assumptions - on which the energy modelling for thefour alternative buildings is based. The Wellington based company e-Cubed Building
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