comparative life cycle assessment - woodworks · few case studies investigating life cycle...

Multi-Story, Cross-Laminated Timber Apartment in Quebec

Comparative Life Cycle Assessment

Presented on October 23rd, 2014 by Blane Grann

Disclaimer:+This+presenta1on+was+developed+by+a+third+party+and+is+not+funded+by+WoodWorks+or+the+So=wood+Lumber+Board.!

“The!Wood!Products!Council”!is!a!Registered!Provider!with!The!American!Ins<tute!of!Architects!Con<nuing!Educa<on!Systems!(AIA/CES),!Provider!#G516.!!!Credit(s)!earned!on!comple<on!of!this!course!will!be!reported!to!AIA!CES!for!AIA!members.!Cer<ficates!of!Comple<on!for!both!AIA!members!and!nonNAIA!members!are!available!upon!request.!!!

This!course!is!registered!with!AIA!CES!for!con<nuing!professional!educa<on.!As!such,!it!does!not!include!content!that!may!be!deemed!or!construed!to!be!an!approval!or!endorsement!by!the!AIA!of!any!material!of!construc<on!or!any!method!or!manner!of!handling,!using,!distribu<ng,!or!dealing!in!any!material!or!product.!___________________________________________

Ques<ons!related!to!specific!materials,!methods,!and!services!will!be!addressed!at!the!conclusion!of!this!presenta<on.!!

!

Course'Descrip,on'

Cross!laminated!<mber!(CLT),!in!combina<on!with!other!engineered!wood!products,!is!crea<ng!new!opportuni<es!for!the!use!of!wood!as!a!structural!material!in!taller!building!systems.!This!presenta<on!examines!the!results!of!a!life!cycle!assessment!(LCA)!comparing!the!environmental!performance!of!a!mul<Nstory!CLT!apartment!building!in!Quebec!with!a!similarly!designed!concrete!slab!building.!While!the!carbon!benefits!related!to!the!use!of!wood!in!building!systems!has!been!well!documented,!LCA!also!highlights!poten<al!tradeNoffs!in!other!impact!categories.!Results!from!this!assessment!underscore!the!importance!of!adop<ng!LCA!in!the!design!phase,!rather!than!as!a!postNhoc!assessment!tool,!to!iden<fy!specific!opportuni<es!to!improve!life!cycle!environmental!performance.!

Learning'Objec,ves'

1.!Iden<fy!(some)!environmental'indicators'used!in!life!cycle!assessment!(LCA)!methodology.!!2.!Evaluate!life'cycle'results'associated'with'the'use'of'cross'laminated',mber'in'a'mul,=story'building.!!3.!Clarify!the!role!of!scenarios!in!building!life!cycle!assessment!for!evalua<ng!future/unknown!events.!!4.!Consider!how!weigh,ng!of!different!environmental!indicators!is!used!in!LCA!to!support!decision!making.!

© 2014 FPInnovations. All rights reserved. Copying and redistribution prohibited. ® FPInnovations, its marks and logos are trademarks of FPInnovations.

Background

5


Life Cycle Assessment

6

Forest Operations

© Jan Paul Lindner, Fraunhofer IBP, Department of Life Cycle Engineering

Material production Transportation

Construction

Operation

Waste management



7

Silviculture

Hauling to roadside

Felling

Road Construction & Maintenance

Delimbing

sawlogs

pulp logs

harvest residues



8

Material and equipment transport

chainsaw

diesel

lubricants 1 hr power sawing Felling

Emission CO2

Emission SO2


Environmental Indicators

!  Resource Use !  Emissions ▫  Global warming potential ▫  Ozone depletion potential ▫  Particulate matter ▫  Smog

9



!  Resource Use !  Emissions ▫  Global warming potential ▫  Ozone depletion potential ▫  Particulate matter ▫  Smog ▫  Acidification potential ▫  Eutrophication potential

13


Image Source: NOAA Environmental Visualization Laboratory

“This year's low-oxygen "dead zone" along Louisiana coast covers 5,052 square miles, an area the size of the state of Connecticut but about 800 square miles less than the 2013 dead zone” The Times-Picayune , August 4th, 2014


!  Resource Use ▫  Abiotic depletion,

elements ▫  Abiotic depletion,

fossil fuels ▫  Land use ▫  Water use

!  Emissions ▫  Global warming potential ▫  Ozone depletion potential ▫  Particulate matter ▫  Smog ▫  Acidification potential ▫  Eutrophication potential ▫  Ecotoxicity ▫  Human toxicity ▫  Ionizing radiation

15

NB: Environmental Indicators presented here are not intended to be comprehensive

EU product environmental footprint/ organizational environmental footprint guidelines (EC, 2013)








16

LEED v4







17

EN 15978:2011 European standard for building LCA







18

TRACI 2.0 US EPA impact assessment method


How do we decide which indicators to select?

!  Choose a standard and use indicators they suggest

!  Normative process ▫  What do we value?

!  Indicator selection in TRACI (Bare, 2011): 1.  Consistency with existing regulations and

policies 2.  Perceived importance 3.  Ease of modelling

19


Comparative Building LCA

20

Photo credit: Jieying Wang, Sylvain Gagnon; Artwork: Sue Rollinson


Overview

!  Comparison based on 4-story, CLT apartment building design in Chibougamau, Quebec ▫  ASHRAE climate zone 7 ▫  4060 m2, 3270 m2 of heated

floor space ▫  24 apartments

!  Updated Results from an ISO 14040 compliant, comparative building LCA (Grann, 2013)

21


Cross- laminated timber

22


Overview

!  Motivation ▫  Few case studies investigating life cycle

performance of cross-laminated timber buildings !  Goal ▫  ISO 14040 compliant LCA comparing:

-  multi-story cross-laminated timber building, and an -  equivalent building which it would likely compete for

market share

23

ISO: International Organization for Standization


Overview

!  CLT building: Floor separation, external wall juncture

!  Cross-laminated timber (CLT)

24

2 x 4” mineral wool

8.2”, CLT

4.1” CLT

2 x 2.5” Mineral wool


Overview

!  CSC building: floor separation, external wall juncture

!  Concrete slab and column with light gauge steel stud walls (CSC)

25

9”, reinforced concrete

Light gauge studs

polystyrene


Overview

!  Structural engineer designed equivalent structural system

!  Industry design guides used to design wall assemblies

!  Building equivalence included: ▫  Floor area ▫  Envelope thermal performance ▫  Equivalent effective R-values

-  Operational energy use assumed to be equivalent ▫  Achieving code for acoustic and fire performance

26


System Boundary: what are we studying?

27

operational energy use

operational water use

maintenance

repair

replacement

refurbishment

raw materials extraction

product manufacturing

demolition

disposal

waste processing

t

t

t

construction

t

reuse, recovery, recycling potential

Included

excluded

use

transportation


Elements Excluded from Study

!  As a simplification, equivalent building elements were also excluded, e.g.: ▫  Foundation walls/slab ▫  Windows and doors ▫  HVAC ▫  Plumbing and electrical ▫  Exterior siding

28


Assumptions

29

!  End of life scenarios ▫  80% recycling rate for all materials ▫  Non-recycled materials sent to

A.  landfill, or B.  incineration

!  Landfilling ▫  23% of carbon in landfilled wood products released

through decay (Dymond, 2012; Skog, 2008) ▫  47% - landfill gas capture rate (10 * 0.23 * 0.47 = 1.1)

2.3 kg C

7.7 kg C

1.2 kg C as CO2 + CH4

1.1 kg C as CO2

10 kg C


Assumptions

!  Operational energy use estimate developed using statistics Canada data ▫  Assumes operational energy use is constant over time

(i.e. no efficiency measures adopted) ▫  Assumes no change in energy supply over time (i.e. no

increase in renewables) !  60 year building lifetime

30







31

EN 15978:2011 European standard for building LCA

Only results for emissions indicators provided in this presentation


N5.00E+05!0.00E+00!5.00E+05!1.00E+06!1.50E+06!2.00E+06!2.50E+06!

CSC,!LF! CLT,!LF! CSC,!INC! CLT,!INC!

Global!Warming!Poten<al!

Results: Life Cycle Stage

32

LF: landfill INC: incineration

CSC: concrete slab and column building system CLT: cross-laminated timber building system

Global warming potential (kg CO2 eq)


System Boundary

33

operational energy use

operational water use

maintenance

repair

replacement

refurbishment

raw materials extraction

product manufacturing

demolition

disposal

waste processing

T

T

T

construction

T

reuse, recovery, recycling potential

Included in system boundary

excluded from system boundary

use


Results

34




N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

2.50E+06!

CSC,!LF! CLT,!LF! CSC,!INC!

CLT,!INC!



System Boundary Expansion

35

material production

transport

construction

demolition

waste management

landfilling incineration

transportation

energy

System boundary for building LCA

Wood products can be provide a significant source of energy at the end of life

1000 sq ft of floor space for 60 year building life + 2000 MJ heat


System Boundary Expansion

36

material production

transport

construction

demolition

waste management

material production

transport

construction

demolition

waste management energy

production

System boundary for concrete slab and column building

System boundary for CLT building

heat heat

The purpose of system expansion is to ensure both studies compare the same services provided to society (i.e. Living space, plus energy services)


Results

37




+77% +26%

N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

2.50E+06!


CLT,!INC!



Results

38


+77% +35% +26% +11%

Error bar represents range of potential values for system expansion

N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

2.50E+06!


CLT,!INC!



Sensitivity of System Expansion

!  Natural gas used as fuel in System Expansion !  Other avoided fuels could include: ▫  Coal ▫  Fuel oil ▫  Ground source heat pump ▫  Solar heating panel

39


0.00E+00!2.00E+05!4.00E+05!6.00E+05!8.00E+05!1.00E+06!1.20E+06!

CSC,!LF!

CLT,!LF!

CSC,!INC!

CLT,!INC!

Acidifica<on!Poten<al!

Results

40


Acidification potential (moles H+ eq)

+522% +105% +10%

Error bar represents range of potential values for system expansion



0!2000!4000!6000!8000!

CSC,!LF!

CLT,!LF!

CSC,!INC!

CLT,!INC!

PM!criteria!air!pollutants!

Results

41

Particulate matter (kg PM < 10 microns eq)

+20% -5%

-5%




N100!100!300!500!700!900!1,100!

N100!100!300!500!700!900!

1100!

CSC,!LF!

CLT,!LF!

CSC,!INC!

CLT,!INC!

Eutrophica<on!Poten<al!

Results

42



Eutrophication potential (kg N eq)

+83% +33% +25%

+15%


Results

43

Ozone depletion potential (kg CFC-11 eq)

0!0.2!0.4!0.6!0.8!


CLT,!INC!

Ozone!Deple<on!Poten<al!

+239%


0.00E+00!

5.00E+04!

1.00E+05!

1.50E+05!

2.00E+05!

CSC,!LF!

CLT,!LF!

CSC,!INC!

CLT,!INC!

Results

44



+19% +15% -14% -4%

Smog potential (kg O3 eq)


Results Summary: Life cycle stage

45

0!

200000!

400000!

600000!

800000!

1000000!

1200000!


Acidifica<on!Poten<al!

0!

1000!

2000!

3000!

4000!

5000!

6000!

7000!

8000!


PM!criteria!air!pollutants!

N100!

100!

300!

500!

700!

900!

1100!


Eutrophica<on!Poten<al!

0!

0.1!

0.2!

0.3!

0.4!

0.5!

0.6!

0.7!

0.8!


Ozone!Deple<on!Poten<al!

0!

50000!

100000!

150000!

200000!








CLT CLT, INC

CSC, LF

CLT CLT, LF

N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

2.50E+06!




Results Summary: Material contributions

46

0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

CSC Building,

LF

CLT Building,

LF

0.0E+00

1.0E+05

2.0E+05

3.0E+05

4.0E+05

5.0E+05

CSC Building,

LF

CLT Building,

LF

0.0E+00 1.0E+03 2.0E+03 3.0E+03 4.0E+03 5.0E+03 6.0E+03 7.0E+03

CSC Building,

LF

CLT Building,

LF

0

200

400

600

800

CSC Building, LF

CLT Building, LF

0.00 0.05 0.10 0.15 0.20 0.25

CSC Building,

LF

CLT Building,

LF

0.0E+00 2.0E+04 4.0E+04 6.0E+04 8.0E+04 1.0E+05 1.2E+05 1.4E+05

CSC Building,

LF

CLT Building,

LF








Sensitivity

!  Sensitivity is used to evaluate the influence of key parameters: ▫  Fuel used in system boundary expansion ▫  Landfill parameters for wood product decay

-  Fraction of wood products that decay in landfills (degradable organic carbon or DOC)

•  23%" 2% (Wang, Padgett, De la Cruz, & Barlaz, 2011; Ximenes, Brooks, Wilson, & Giles, 2012)

-  Landfill gas capture rate (R) •  47% " 80%

47


N1.00E+06!

N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

CSC,!LF! CLT,!LF! CLT,!80%!R!

CLT,!2%!DOC!

Sensitivity: Landfill Parameters

48


-51% -23%

R: Landfill gas capture rate; DOC: fraction of wood carbon that degrades


Normalization and Weighting


Normalization and Weighting

!  Normalization involves comparing an indicator to a pre-defined amount ▫  e.g. All GHG emissions from the US in 2010

!  Weighting is the process of deciding which indicators are of highest importance (based on our values)

Q: Which product is preferable if, 4 indicators are lower and 2 are higher?

50


Normalization and Weighting to Support Decision Making

!  Weighting is optional in ISO 14040 !  Adds controversy because value choices are

introduced !  Several types of weighting, e.g.: ▫  Monetization ▫  Panel weighting

51


Normalization and Weighting to Support Decision Making !  Weighting in LEED v4 ▫  Global warming potential and two additional indicators

must decrease by >10% ▫  No other indicator may increase by >5%

!  Building for Environmental and Economic Sustainability (BEES) ▫  US Environmental Protection Agency Science advisory

panel ▫  Stakeholder (building product producers, green building

experts, LCA experts) panel ▫  Harvard study

52


Weighting Options in BEES

53

0 5

10 15 20 25 30 35

Perc

enta

ge

EPA Weighting Stakeholder weighting Harvard weighting


Improvement Potential

!  Relatively high contribution from mineral wool acoustic batts in CLT building ▫  How would replacing mineral wool, acoustic floor

batts in CLT building with cellulose insulation affect results?

54


N1.00E+06!

N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

CSC,!LF! CLT,!LF! CLT,!cellulose!


55


-6%


Improvement potential

56

0.00E+00!

1.00E+05!

2.00E+05!

3.00E+05!

4.00E+05!

5.00E+05!



-17%


Improvement potential

57

0.00E+00!1.00E+03!2.00E+03!3.00E+03!4.00E+03!5.00E+03!6.00E+03!7.00E+03!

0.00E+00!1.00E+02!2.00E+02!3.00E+02!4.00E+02!5.00E+02!6.00E+02!7.00E+02!



-43%

-11%



58


0.00E+00!2.00E+04!4.00E+04!6.00E+04!8.00E+04!1.00E+05!1.20E+05!1.40E+05!


-25%


Conclusions

!  Operational energy had largest impacts ▫  Likely to be much higher in regions where electricity is not dominated

by hydro power as in Quebec ▫  But, could also be smaller for the Quebec case study if potential

future changes were included in model for: -  energy efficiency -  change in energy supply

!  Materials used for structural systems and insulation were also key ▫  CLT building shifts material impacts from structural materials to

acoustic batts ▫  Landfilled drywall was an important contributor to acidification for both

buildings

59


Conclusions

!  Results showed key differences in favour of the CLT building system for: ▫  Global warming potential (largest) ▫  Eutrophication potential ▫  Acidification potential

-  Incineration scenario only

!  Slight advantage for the CSC building for: ▫  Particulate matter and Smog

-  Landfill scenario only

!  Scenarios are important for evaluating a range of possible outcomes

60


Conclusions

!  Assumptions used for system boundary expansion influence indicators for smog and particulate matter

!  Life cycle assessment can identify opportunities for improving environmental performance ▫  e.g. Cellulose

!  Normalization and weighting can be used to support decision making for multiple indicators

61


Acknowledgements

•  This research was financially supported by the BC Ministry of Advanced Education, Innovation and Technology and by the Canadian Forest Service under the contribution agreement between the Government of Canada and FPInnovations.

•  Additional funding for travel and developing the presentation provided by the Softwood Lumber Board and WoodWorks

62

www.fpinnovations.ca

Follow us on


Questions? For more information contact: Blane Grann [email protected]


!  Forests influence climate through: ▫  Carbon storage ▫  Surface reflectance ▫  Evapotranspiration

64

!  Disagreements over how to account for climate impacts of forest disturbance in LCA

Key factors at northern latitudes

Forests and climate: Additional environmental information


N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

2.50E+06!

CSC,!LF! CLT,!LF! CSC,!INC!CLT,!INC!


Additional Results: Dynamic climate effects

65


+48% +52% +43% +26%



Additional Results: Dynamic climate effects

66

N1.00E+06!

N5.00E+05!

0.00E+00!

5.00E+05!

1.00E+06!

1.50E+06!

2.00E+06!

CSC,!LF!

CLT,!LF!

CLT,!80%!R!

CLT,!2%!DOC!


-24% -14%

R: Landfill gas capture rate; DOC: fraction of wood carbon that degrades


Annual Forest Disturbance in Canada

67

0

10

20

30

40

50

1990

19

91

1992

19

93

1994

19

95

1996

19

97

1998

19

99

2000

20

01

2002

20

03

2004

20

05

2006

20

07

2008

20

09

2010

20

11

2012

Hec

tare

s (m

illio

n)

Total Area Burned Total Area Defoliated Total Area Harvested

Data Source: National Forestry Database


Life Cycle Inventory Data Sources

!  Materials, transport, construction and demolition ▫  Athena Impact Estimator for Buildings v4.5

(Athena Sustainable Materials Institute) !  Disposal ▫  ecoinvent v2.2 (Swiss Centre for Life Cycle

Inventories) ▫  US-EI 2.2 (Earth Shift)

68

comparative life cycle assessment - woodworks · few case studies investigating life cycle...

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