Wood plays an important role in combating climate change by storing carbon extracted from the atmosphere during photosynthesis. About half the weight of wood is carbon. Wood construction requires less fossil fuels than other materials like concrete and stores carbon throughout the lifetime of wood products. Case studies show wooden buildings can have lower lifecycle carbon footprints than non-wood alternatives. A holistic, collaborative design process is important to ensure low carbon footprints by making informed material and system choices early in the design phase.

1. The role of wood
in carbon efficient construction
Finnish Green Building Council
28.02.2013
Matti Kuittinen

2. CARBON EFFICIENCY

3. ENERGY EFFICIENCY CARBON EFFICIENCY

5. Record-amount of greenhouse gases in the atmosphere.

6. Around 40% of greenhouse gas emissions originate from the built environment.
Cement manufacturing alone causes 5-7% of global GHG emissions.

7. Sustainable forests
Land Fossil fuel reserves
Oceans
Fossil fuel reserves cause one-way emissions to atmosphere

8. Forests have a vital role in combating climate change

9. Solar energy
6CO2 C6H1206 6O2
6H2O
In photosynthesis the carbon from atmosphere is stored in biomass

10. 6%
H
50%
C
O 44%
Half of wood material is carbon

11. Less fossil fuels are generally
required for the manufacturing of
wood products
6%
1
Manufacturing creates
Products serve as generally less greenhouse
carbon storage for
their use period.
4 2 gas emissions
44%
3
Recycling the products into energy
can substitute fossil fuels in the end
of lifecycle
Climate benefits of wood in construction

12. THE ROLE OF WOOD

13. CO2
CO2
CO2 C
C
s s
C C
s C
C
±
C
s
CO2
C
C CO2
CO2 CO2
CO2
s
C
REPAIR
REPAIR
REPAIR
RAW MATERIAL PRODUCTION CONSTRUCTION USE END-OF-LIFE
s SUBSTITUTION EFFECT ± INCREASE /
DECREASE OF
CO2 FORESTS
ENERGY SOURCES EMISSIONS
CONSTRUCTION PRODUCTS

14. Should we store carbon in forests or wood products?
Source: Life cycle impacts of forest management and wood utilization on carbon mitigation. Lippke et.al. Carbon management 2011, 303-333.

15. Should we store carbon in forests or wood products?
Source: Life cycle impacts of forest management and wood utilization on carbon mitigation. Lippke et.al. Carbon management 2011, 303-333.

16. CASE STUDIES

17. Carbon footprint of the full lifecycle of a wooden house
Source: €CO2 project, Linnaeus University + SP Trätek
PRODUCT
PHASE
CONSTRUCTION
PHASE
USE PHASE
END OF LIFE
PHASE
0 200 400 600 800
Carbon footprint (kg CO2 /m2)

18. Carbon footprint of the full lifecycle of a wooden passive house
Source: €CO2 project, Linnaeus University + SP Trätek
PRODUCT
PHASE
CONSTRUCTION
PHASE
USE PHASE
END OF LIFE
PHASE
0 200 400 600 800
Carbon footprint (kg CO2 /m2)

19. European comparison in €CO2 project
Wälludden, Sweden Mietraching, Germany L’Aquila, Italy
Tervakukka, Finland Joensuun Elli, Finland Box test buildings, Finland
Muehlweg, Austria Schoenkirchen, Austria Steinbrechergasse, Austria

20. Assessment method Manual inventory and impact assessment with the help of Building parameters
templates created in the €CO2 research project. Based on m2 m3
Gross floor area 258 Gross volume 1036
ISO14067 (2012), EN 15804 and EN 15987.
Nett floor area 198 m2 Nett volume 567 m3
Living area 198 m2 Occupants 4 person
Point of assessment Pre-design X Design Construction
Use Renovation End-of-life Area and volume definitions based on: Finnish building regulations
Valid until Date of assessment
(not defined) 14.6.2012

21. U = 0,135 W/m2K
Floor material
80 mm Concrete slab
200 mm EPS insulation
300 mm Capillary break (gravel)
Compacted gravel
Geotextile
Soil
Base floor Carbon footprint
kg CO2e /m2

22. 28 Chip board
mm
Plastic carpet strips for sound
insulation
75 Beams 75x100 cc 600
mm
Plastic carpet strips for sound
insulation
400 I-beams cc 300 with 200mm
mm blown cellulose fibre insulation
32 Battens 32x50 cc 400
mm
Ceiling material
Intermediate floor Carbon footprint
kg CO2e /m2

23. U = 0,11 W/m2K
28 mm Wooden external cladding
25 + 25 mm Horizontal and vertical planks
25 mm Wind barrier board (LDF)
400 mm I-joist cc 600 with blown
cellulose fibre insulation (dry
density > 25 kg/m3)
0,2 mm Air barrier textile
12 mm Plywood board
48 mm Vertical battens 48x48 cc 600
Interiour cladding
External wall Carbon footprint
kg CO2e /m2

24. Internal walls Carbon footprint
kg CO2e /m2

25. Roof
U = 0,09 W/m2K
Steel roofing
5 mm Acoustic insulation strips
22 mm Wooden planks
50 mm Wooden battens
Condensation barrier
120 mm Ventilation cavity beams
50x150 cc 900
9 mm Gypsum board
600 mm Wooden truss with blown
cellulose fibre insulation (dry
density > 25 kg/m3)
0,2 mm Air barrier textile
32 mm Battens 32x100
Interiour cladding
Carbon footprint
kg CO2e /m2

27. PRACTICAL STEPS

28. A holistic approach is needed
USE+MAINTENANCE ECONOMIC SERVICE LIFE
ENERGY CONCEPT
U-VALUE ENERGY DEMAND
AMOUNT
INSULATION
MATERIAL TYPE
CARBON
LIFE CYCLE CARBON
FOOTPRINT OF
FOOTPRINT OF A
CONSTRUCTION
OTHER MATERIALS BUILDING
PRODUCTS
MOISTURE
STRUCTURE TECHNICAL SERVICE LIFE
SAFETY
QUALITY OF USE AND
CONSTRUCTION MAINTENANCE
WORK
QUALITY OF DESIGN
3/5/2013

29. Fundamental problem in design phase
Decisions effecting Amount and
the carbon footprint accuracy of data
Sketch Building Working Site
Pre-design Biddings
phase permission drawings supervision
Need for a new design approach

30. 1 PRE-DESIGN PHASE CLIENTS REP. ARCHITECT STRUCTURAL ENGINEER HVAC ENGINEER ELECTRIC AND AUTOMATION DESIGNERS
Requirements: Site alternatives
- functional
- spatial
Carbon efficient Room programme Structural scenarios? HVAC scenarios? Participation if
- financial
- operational
- environmental Normative requirements
- legal
- service life
design process - other
Selection of green
Establishment of
architectural
requirements
Establishment of
structural requirements
Establishment of HVAC
and energy requirements
building certification
system
Lifecycle carbon footprint
goals and assessment
• A generic design process methodology
2 PRELIMINARY DESIGN CLIENTS REP. ARCHITECT STRUCTURAL ENGINEER HVAC ENGINEER ELECTRIC AND AUTOMATION DESIGNERS
flow has been enhanced
Comparison to goals of Site use Target values for energy efficiency
with vital tasks for ensuring the project
Functional concept Structural pre-design HVAC pre-design Electricity pre
low carbon footprint Building shape and size
Preliminary structure and frame types, amount of openings
• Tasks are assigned to Preliminary energy
simulation and iteration
• Constructor Preliminary carbon
footprint estimation and
• Architect Quick check for selected
green building
certification system
• Structural engineer
3 FINAL DESIGN CLIENTS REP. ARCHITECT STRUCTURAL ENGINEER HVAC ENGINEER ELECTRIC AND AUTOMATION DESIGNERS
• HVAC and electric designer
Final architectural design Detailed structural design Detailed HVAC design / Detailed electric
Participation if
/ BIM model / BIM model BIM model
• Element manufacturer BIM model
Preliminary bill of quantities for structual components Preliminary device and component selection / BoQ
• The process flow underlines Energy certificate
mutual understanding of Decision on means to
Detailed carbon footprint estimation with design alternatives
goals and correctly timed reach planned carbon
Approval of designs and Marketing materials,
exchange of information 4 PERMISSION PLANNING
specifications images and virtual models
Application drawings
Submission of application Application drawings and documents
documents (if required)
5 WORKING DRAWINGS
Architectural working Structural working HVAC working drawings Electricity working
drawings / BIM model drawings / BIM model and details drawings and details

32. 5.3.2013

33. Borgrund Stave Church, Norway
Built 1150 A.D.

34. Thank you!
Matti Kuittinen
Tel. +358 50 594 7990
matti.kuittinen@aalto.fi