Date post: | 11-Jan-2016 |
Category: |
Documents |
Upload: | augustus-mccormick |
View: | 227 times |
Download: | 0 times |
Life Cycle Assessment of a New Zealand house
Barbara Nebel & Zsuzsa Szalay
Scion
“exemplar house”
Specifically designed as an example for research on residential costing (Willson 2002)
two storey design three bedrooms and a
garage total floor area of 195
m2
Building construction
suspended timber floor with foil / concrete slab on ground floor;
Light timber frame walls with fibre glass insulation, plasterboard internal lining with paint finish, external cladding weatherboard/ fibre cement/ brick;
pitched timber truss roof, flat ceiling with insulation lined with plasterboard, steel cladding/concrete tiles;
aluminium frame windows without thermal break.
Life Cycle Assessment
Life Cycle Assessment Framework
Goal and scope definition
Interpretation
Impact assessment
Inventory analysis
Direct applications:
• Product development and improvement
• Strategic planning
• Public policy making
• Marketing
• Other
Goal and Scope
Develop a generic LCA model for houses for research purposes
Compare six design alternatives Find the environmental hot-spots Analyse embodied and operational
environmental impacts
Functional unit: the Exemplar house over a 50-year period in New Zealand
Scenarios Six design alternatives
Three heating fuels: wood, gas, electricity Three locations: Auckland, Wellington, Queenstown
Name Floor Wall cladding Roof cladding Timber/WB/steel Suspended timber Weatherboard Steel Timber/FC/steel Suspended timber Fibrecement Steel Concrete/WB/steel Slab on ground
concrete Weatherboard Steel
Concrete/FC/steel Slab on ground concrete
Fibrecement Steel
Concrete/brick/steel Slab on ground concrete
Brick veneer Steel
Concrete/brick/concrete Slab on ground concrete
Brick veneer Concrete
Data
Average data from Europefor New Zealand only embodied energy and
CO2-emissions are available (Alcorn)
Data gaps:Dataset for carpet was based on GaBi data
and a European study (Potting 1994)Timber treatment is missing
Maintenance
Life time of building is 50 years Average life time of building elements based
on New Zealand and European data
Prorating was applied due to the high level of uncertaintiesLife time of building element is 20 yearsNumber of replacements:
50/20 -1 = ? 1.5
Operation
Hot water, ventilation, cooling, lighting, appliances not considered
Heating energy calculated with ALF3 (BRANZ) heating levels: 16, 18, 20 °C heating schedules: evening, morning and
evening, all day, 24 hour heating
Insulation as required by NZ Building Code
GaBi model
Production
Heating energy demand
Wellington, 24 hour heating, 20 °C
-10000
-5000
0
5000
10000
15000
20000
25000
Concrete/FC/steel
Timber/ FC/steel Concrete/WB/steel
Concrete/brick/steel
Concrete/brick/concrete
Timber/ WB/steel
En
erg
y b
alan
ce (
kWh
/yea
r)Floors Walls Windows Roof Air leakage Warm-up load Internal gains Solar gains
Wellington, evening heating only, 18 °C
-10000
-5000
0
5000
10000
15000
20000
25000
Concrete/FC/steel
Timber/ FC/steel Concrete/WB/steel
Concrete/brick/steel
Concrete/brick/concrete
Timber/ WB/steel
En
erg
y b
alan
ce (
kWh
/yea
r)
Floors Walls Windows Roof Air leakage Warm-up load Internal gains Solar gains
Evening heating, 18°C 24 hour heating, 20°C
Thermal mass
Influence of floor
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
Auckland, eveningheating only, 18 °C
Auckland, 24 hourheating, 20 °C
Queenstown, eveningheating only, 18 °C
Queenstown, 24 hourheating, 20 °C
En
erg
y d
eman
d (
kWh
/yea
r)
Timber/FC/steel Concrete/FC/steel Concrete/FC/steel no carpet
Impact categories
Non-renewable energy demand Renewable energy demand Global warming Ozone depletion Eutrophication Acidification Photo-oxidant formation
Building materials
Non-renewable energy content of building materials (MJ)
0
50000
100000
150000
200000
250000
300000
Con/FC/s teel
Tim /FC/s teel
Con/WB/s teel
Con/brick/s teel
Con/brick/con
Tim /WB/s teel
Malthoid
Paper
Paint
Gypsum board
Plas tics
Carpet
Fibre glass
Glass
Alum inium
Steel
MDF
Particleboard
Tim ber
Fibre cem ent
Brick
Plas ter
Gravel and sand
Concrete
Material quantities (kg)
0
20000
40000
60000
80000
100000
120000
140000
Con/FC/s teel
Tim /FC/s teel
Con/WB/s teel
Con/brick/s teel
Con/brick/con
Tim /WB/s teel
Malthoid
Paper
Paint
Gypsum board
Plas tics
Carpet
Fibre glass
Glass
Alum inium
Steel
MDF
Particleboard
Tim ber
Fibre cem ent
Brick
Plas ter
Gravel and sand
Concrete
Building elements
Non-renewable energy content of building elements (MJ)
0
50000
100000
150000
200000
250000
300000
Con/FC/steel
Tim/FC/steel
Con/WB/steel
Con/brick/steel
Con/brick/con
Tim/WB/steel
Plumbing
Stairs
Interior doors
Windows
Roof
Wall
Floors
Foundation
Wall components
Non-renewable energy content of wall components (MJ)
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
Con/FC/s teel
Tim /FC/s teel
Con/WB/s teel
Con/brick/s teel
Con/brick/con
Tim /WB/s teel
Wallpaper
Paint
Gypsum board
Fibre glass
Steel bracing
Tim ber fram e
Paint
Weatherboards
Fibrecem ent
Brick cladding
Tim ber battens
Building paper
Foundation and floor
Non-renewable energy content of foundation and floor (MJ)
0
20000
40000
60000
80000
100000
120000
Con/FC/steel
Tim/FC/steel
Con/WB/steel
Con/brick/steel
Con/brick/con
Tim/WB/steel
Gypsum board
Paint
Fibre glass ins
Plaster
Timber frame
Steel
Timber nogging
Particleboard
Aluminum
Carpet Nylon
PVC vinyl
Timber
Steel
Gravel and sand
Polyethylene DPC
Concrete
PVC
Fibrecement
Roof components
Non-renewable energy content of roof components (MJ)
0
5000
10000
15000
20000
25000
30000
35000
40000
Con/FC/s teel
Tim /FC/s teel
Con/WB/s teel
Con/brick/s teel
Con/brick/con
Tim /WB/s teel
PVC spouting
Concrete tile
Colors teel roofing
Building paper
Steel
Tim ber fram e
Paint
PVC
Tim ber
Fibre cem ent
Life cycle energy
Non-renewable energy (MJ), Wellington electricity
0
200000
400000
600000
800000
1000000
1200000
Con/ FC/steel Tim/ FC/steel Con/ WB/steel Con/brick/steel
Con/brick/con
Tim/ WB/steel
Construction Maintenance Use End of life
Life cycle energy
Non-renewable energy (MJ)
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
End of life
Use
Maintenance
Construction
Timber/ WB/ steel
Environmental impacts
Timber/ WB/ steel, Wellington
Gas heating
Timber/WB/steel, Wellington gas
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Non-renew ableenergy
GWP ODP EP AP POCP
Construction Maintenance Use End of life
Timber/WB/steel, Wellington electricity
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Non-renew ableenergy
GWP ODP EP AP POCP
Construction Maintenance Use End of life
Timber/ WB/ steel, Wellington
Electric heating
Transport distances
Influence of transport distancesConcrete/FC/steel, Wellington electricity
0
20
40
60
80
100
120
Energy GWP ODP EP AP POCP
% o
f b
as
e s
ce
na
rio
Construction Maintenance Use End of life
100 km - 50 km - 200 km
Useful life of carpet
Influence of carpet lifeConcrete/FC/steel, Wellington electricity
0
20
40
60
80
100
120
Energy GWP ODP EP AP POCP
% o
f b
as
e s
ce
na
rio
Construction Maintenance Use End of life
10 years – 8 years – 15 years
Conclusions
For typical New Zealand heating level and schedule, materials have significant influence on life cycle results
Interesting results relating to thermal mass in intermittent heating schedule
Materials need to be looked at on component level
LCA is good tool to optimise building design
Tool can be used for other house designs based on data from quantitiy surveyor
Outlook
New Zealand inventory data for building materials
Insulation scenarios: NZS better and best practice
Statistical model to represent current building stock
Model retrofit of an existing house with insulation in walls
Futher information
Barbara Nebel, PhDGroupleader Sustainability FramworksSustainable Consumer ProductsPrivate Bag 3020, ROTORUA, New ZealandPhone +64 7 343 5637
Email: [email protected]