Design For Deconstruction - US Environmental Protection Agency

More documents

Recommendations

Info

SETTING PRIORITIES DESIGN FOR DISASSEMBLY 28 After establishing the quantities of materials in these three projects, we wanted to understand their relative environmental impacts. A true Life Cycle Analysis (LCA) would be desirable, but the data and tools in this field are still in their developmental stages and it is beyond the scope of this analysis. As a proxy for a true LCA, we chose to look at carbon emissions. Carbon emissions capture probably the most critical environmental issue: climate change. It also generally corresponds to embodied energy, and therefore the wide range of ecological impacts related to energy use. It does not address a host of issues including toxicity, impacts on forests, ecosystems, and biodiversity, etc; so when referring to the results, care should be taken to remember the limitations of this analysis. Lbs CO2/Lbs Material 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 - Figure 4.6 Pounds of Carbon per pound of material embodied in common construction materials. The first task was to determine the embodied carbon per unit of material. This information was primarily extracted from the ATHENA Life Cycle Assessment software developed by the Athena Institute. To improve confidence in the data it was compared to a variety of other sources, including the paper “Carbon Intensity Ratios” by Richard MacMath and Pliny Fisk III of the Center for Maximum Potential Building Systems. The embodied carbon associated with each material is shown in figure 4.6. Concre t e St ru ctu r al S te el St a nding Seam M eta l Roo f ing Reinfor c ing S tee l Raised Access F lo or Built Up Roofing Carpet Metal S t ud Fram in g Gl a ss Al u min u m W i ndo w Frames Gy p sum Bo a rd Metal D o or F ram e s Batt Insulati o n Hollow M eta l Doors Cerami c Tile Ac o ust ic al T i le Wood Doors Pl y woo d Cemen t Pla s ter Wood Wall Studs Agriboard Ex t erio r Wood Si d ing In te rior or woo d T& G pa nelin g
It is instructive to note the wide variation between materials, with aluminum being close to a factor of 100 greater than concrete in lbs of CO2 per pound of material. This can be deceptive in two ways: aluminum is a lightweight material used in limited quantities while concrete is a heavy material used in mass quantities. Tons of Material The embodied carbon factors were then multiplied by the total weight of each material in the three projects, and divided by the square feet of each building to normalize the results. An example of the calculation is shown in figure 4.7, and the results for each building are graphed in figure 4.8 and 4.9. CO2 Emission Factor Tons of CO2 CO2 Percent of Total Concrete 1,007.4 0.11 109.8 32.5% Reinforcing Steel 24.6 1.06 26.0 7.7% Structural Steel 17.4 1.33 23.1 6.8% Standing Seam Metal Roofi ng 9.6 2.50 24.0 7.1% Built Up Roofi ng 19.7 2.67 52.5 15.5% Tile Carpet 4.3 3.10 13.5 4.0% Metal Stud Framing - 2.04 - 0.0% Glass 12.9 1.54 19.9 5.9% Aluminum Window Frames 2.0 9.17 18.3 5.4% Gypsum Board 38.5 0.39 14.9 4.4% Metal Door Frames 1.3 2.00 2.6 0.8% Batt Insulation 3.1 3.28 10.2 3.0% Hollow Metal Doors 1.1 2.00 2.2 0.7% Ceramic Tile 1.6 1.40 2.3 0.7% Wood Doors 2.0 0.15 0.3 0.1% Plywood 37.5 0.17 6.4 1.9% Cement Plaster 58.8 0.09 5.1 1.5% Wood Wall Studs 106.0 0.03 3.2 1.0% Agriboard 3.1 0.07 0.2 0.1% Exterior Wood Siding 1.3 0.12 0.1 0.0% Interior wood T&G paneling 23.6 0.15 3.4 1.0% TOTALS 1,376 338.2 Figure 4.7 Chartwell School Embodied CO2 Calculations SETTING PRIORITIES DESIGN FOR DISASSEMBLY 29
Page 1: DESIGN FOR DECONSTRUCTION
Page 5: Preface The ultimate goal of the De
Page 8 and 9: OVERVIEW DESIGN FOR DISASSEMBLY 8 S
Page 10 and 11: OVERVIEW DESIGN FOR DISASSEMBLY 10
Page 12 and 13: LESSONS FROM THE FIELD DESIGN FOR D
Page 21 and 22: 3. DFD Principles and Strategies Wh
Page 23: Building Systems Consider building
Page 26 and 27: SETTING PRIORITIES DESIGN FOR DISAS
Page 48: OVERVIEW DESIGN FOR DISASSEMBLY 48

Design For Deconstruction - US Environmental Protection Agency

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?