1. IMPACT OF BUILDING'S LIFESPAN ON THE LIFE CYCLE ASSESSMENT
Karel STRUHALA, Zuzana STRÁNSKÁ
Faculty of Civil Engineering, Brno University of Technology,

2. Introduction - Objectives
Objectives of the assessment
Evaluation of environmental impacts of selected building‘s life cycle
Comparison of results in regard to varying service life lengths ( years)
5-year steps
Total results and annual results per per 1m2 of building‘s area
Comparison of four service life scenarios
Three scenarios include repairs and renovations
One scenario with varying occupancy

3. Introduction – Assessed Building
General information
Two-storey detached house without basement
Net floor area m2
Four tenants (according to designs)
Building site located in Eastern Bohemia
Structures
Reinforced concrete foundations insulated with XPS
External Walls and roof made of SIPs (Structural Insulated Panels) insulated with mineral wool
Interior walls made of SIPs with plasterboard cladding
Floor made of timber beams and OSB boards with plasterboard cladding
Plastic doors and windows with double or triple glazing

4. Introduction – Assessed Building
Equipment
Heating and DHW – gas fireplace/boiler
Mechanical ventilation – central ventilation unit, plastic ducts
Sanitary equipment – common equipment (shower, bathtub, sink, etc.); no water conservation measures
No renewable energy sources
Designed annual energy and water consumption and waste production (4 tenants)
70.0 GJ of natural gas
5.76 GJ of electric energy
58.4 m3 of water
790 kg of municipal waste

5. Methodology and Tools Life Cycle Assessment (LCA) System boundaries
Based on ISO and following standards (especially EN 15978)
The EN divides a building’s life cycle into four stages and 16 modules:
Product stage – modules A1 to A3
Construction stage – modules A4 and A5
Use stage – modules B1 to B7
End of life stage – modules C1 to C4
System boundaries
Cradle-to-Grave system boundaries – modules A1 to C4 according to EN , excluding module B5 Refurbishment
The amounts of materials, energy, etc. are based on the design documentation
Only the building and processes directly connected with it and its use are included in the assessment – e.g. the landscaping is not included

6. Methodology and Tools Characterization model
The results are calculated using CML2001 (version November 2010) characterization factors
Normalization CML 2001 EU 25 (version November 2010) is used to simplify the comparison of results of individual scenarios
Results in seven out of 12 available impact categories are presented – those required by EN 15978:
Abiotic depletion (ADP elements)
Abiotic depletion (ADP fossil)
Acidification Potential (AP)
Eutrophication Potential (EP)
Global Warming Potential (GWP)
Ozone Layer Depletion Potential (ODP)
Photochemical Ozone Creation Potential (POCP)

7. Methodology and Tools Tools and databases GaBi 4 tool
Ecoinvent 2.0 database
Some simplifications and estimations had to be made due to the lack of suitable data in the design or in the database – especially in regard to the construction and deconstruction processes and waste management
Some materials are not included in the database. Two or more individual processes are used to represent them
Energy and water consumption during the construction of the building (module A5 according to EN 15978) were estimated based on the consultations with the builder
Waste management scenario (landfilling) is based on information about waste management in Czech Republic (Czech Environmental Information Agency; 2015)

8. Assessed Scenarios
Series of four scenarios consecutive scenarios is compared and evaluated
S1 – “Erroneous” reference scenario
Includes the production of materials and construction of the building (modules A1 to A5)
Use of the building is insufficiently addressed – a common mistake in design of buildings as well as in LCAs
Modules B3 Repair, B4 Replacement and B5 Refurbishment are not included
Energy and water consumption and waste production are constant, corresponding with designed occupancy (four tenants)
End of life scenario includes demolition and landfilling

9. Assessed Scenarios S2 – “Proper” reference scenario
Includes the production of materials and construction of the building (modules A1 to A5)
Use of the building includes repairs and replacement of structures and equipment
E.g. estimated service life of the ventilation unit is 20 years
Energy and water consumption and waste production are constant, corresponding with designed occupancy (four tenants)
End of life scenario includes demolition and landfilling

10. Assessed Scenarios S3 – Neglected maintenance scenario
Includes the production of materials and construction of the building (modules A1 to A5)
Use of the building includes repairs and replacement of structures and equipment
E.g. estimated service life of the ventilation unit is 20 years
Scenario expects that the tenants would neglect the maintenance of the building and equipment. This is represented by increasing energy consumption (e.g. due to worsening efficiency of the boiler or failure)
Energy and water consumption and waste production are constant, corresponding with designed occupancy (four tenants)
End of life scenario includes demolition and landfilling

11. Assessed Scenarios
S4 – Neglected maintenance and varying occupancy scenario
Includes the production of materials and construction of the building (modules A1 to A5)
Use of the building includes repairs and replacement of structures and equipment
E.g. estimated service life of the ventilation unit is 20 years
Scenario expects that the tenants would neglect the maintenance of the building and equipment. This is represented by increasing energy consumption (e.g. due to worsening efficiency of the boiler)
Energy and water consumption and waste production are fluctuating (estimated) due to varying occupancy – between two and four tenants in time
End of life scenario includes demolition and landfilling

12. Assessed Scenarios
Varying occupancy in S4 scenario

13. Assessed Scenarios
Heating energy consumption comparison of all scenarios

14. Results Total environmental impacts per 1 m2 of net floor area
50-year building’s service life
Impact cat.
Scenario S1
Scenario S2
Scenario S3
Scenario S4
Unit
ADP elements
8,47E-03
1,21E-02
1,22E-02
kg Sb-Eq.·m-2
ADP fossil
7,30E+01
7,65E+01
7,83E+01
MJ·m-2 AP
7,70E+00
8,68E+00
8,84E+00
8,78E+00
kg SO2-Eq.·m-2 EP
4,76E+00
4,89E+00
4,93E+00
3,94E+00
kg Phos.-Eq.·m-2
GWP
3,59E+03
3,80E+03
3,96E+03
3,88E+03
kg CO2-Eq.·m-2
ODP
1,76E-03
3,05E-03
3,07E-03
kg R11-Eq.·m-2
POCP
1,25E+00
1,37E+00
1,41E+00
1,39E+00
kg Eth.-Eq.·m-2
100-year building’s service life
Impact cat.
Scenario S1
Scenario S2
Scenario S3
Scenario S4
Unit
ADP elements
1,04E-02
2,50E-02
2,52E-02
2,51E-02
kg Sb-Eq.·m-2
ADP fossil
1,36E+02
1,50E+02
1,55E+02
1,54E+02
MJ·m-2 AP
1,25E+01
1,64E+01
1,68E+01
1,67E+01
kg SO2-Eq.·m-2 EP
8,83E+00
9,46E+00
9,54E+00
7,60E+00
kg Phos.-Eq.·m-2
GWP
7,11E+03
7,94E+03
8,38E+03
8,18E+03
kg CO2-Eq.·m-2
ODP
2,16E-03
6,06E-03
6,13E-03
6,12E-03
kg R11-Eq.·m-2
POCP
2,03E+00
2,49E+00
2,59E+00
2,55E+00
kg Eth.-Eq.·m-2

15. Results Total environmental impacts per 1 m2 of net floor area
50-year building’s service life
Impact cat.
Scenario S1
Scenario S2
Scenario S3
Scenario S4
Unit
ADP elements
8,47E-03
1,21E-02
1,22E-02
kg Sb-Eq.·m-2
ADP fossil
7,30E+01
7,65E+01
7,83E+01
MJ·m-2 AP
7,70E+00
8,68E+00
8,84E+00
8,78E+00
kg SO2-Eq.·m-2 EP
4,76E+00
4,89E+00
4,93E+00
3,94E+00
kg Phos.-Eq.·m-2
GWP
3,59E+03
3,80E+03
3,96E+03
3,88E+03
kg CO2-Eq.·m-2
ODP
1,76E-03
3,05E-03
3,07E-03
kg R11-Eq.·m-2
POCP
1,25E+00
1,37E+00
1,41E+00
1,39E+00
kg Eth.-Eq.·m-2
22.92% increase
100-year building’s service life
Impact cat.
Scenario S1
Scenario S2
Scenario S3
Scenario S4
Unit
ADP elements
1,04E-02
2,50E-02
2,52E-02
2,51E-02
kg Sb-Eq.·m-2
ADP fossil
1,36E+02
1,50E+02
1,55E+02
1,54E+02
MJ·m-2 AP
1,25E+01
1,64E+01
1,68E+01
1,67E+01
kg SO2-Eq.·m-2 EP
8,83E+00
9,46E+00
9,54E+00
7,60E+00
kg Phos.-Eq.·m-2
GWP
7,11E+03
7,94E+03
8,38E+03
8,18E+03
kg CO2-Eq.·m-2
ODP
2,16E-03
6,06E-03
6,13E-03
6,12E-03
kg R11-Eq.·m-2
POCP
2,03E+00
2,49E+00
2,59E+00
2,55E+00
kg Eth.-Eq.·m-2

16. Results Total environmental impacts per 1 m2 of net floor area
50-year building’s service life
Impact cat.
Scenario S1
Scenario S2
Scenario S3
Scenario S4
Unit
ADP elements
8,47E-03
1,21E-02
1,22E-02
kg Sb-Eq.·m-2
ADP fossil
7,30E+01
7,65E+01
7,83E+01
MJ·m-2 AP
7,70E+00
8,68E+00
8,84E+00
8,78E+00
kg SO2-Eq.·m-2 EP
4,76E+00
4,89E+00
4,93E+00
3,94E+00
kg Phos.-Eq.·m-2
GWP
3,59E+03
3,80E+03
3,96E+03
3,88E+03
kg CO2-Eq.·m-2
ODP
1,76E-03
3,05E-03
3,07E-03
kg R11-Eq.·m-2
POCP
1,25E+00
1,37E+00
1,41E+00
1,39E+00
kg Eth.-Eq.·m-2
22.92% increase
111.50% increase
100-year building’s service life
Impact cat.
Scenario S1
Scenario S2
Scenario S3
Scenario S4
Unit
ADP elements
1,04E-02
2,50E-02
2,52E-02
2,51E-02
kg Sb-Eq.·m-2
ADP fossil
1,36E+02
1,50E+02
1,55E+02
1,54E+02
MJ·m-2 AP
1,25E+01
1,64E+01
1,68E+01
1,67E+01
kg SO2-Eq.·m-2 EP
8,83E+00
9,46E+00
9,54E+00
7,60E+00
kg Phos.-Eq.·m-2
GWP
7,11E+03
7,94E+03
8,38E+03
8,18E+03
kg CO2-Eq.·m-2
ODP
2,16E-03
6,06E-03
6,13E-03
6,12E-03
kg R11-Eq.·m-2
POCP
2,03E+00
2,49E+00
2,59E+00
2,55E+00
kg Eth.-Eq.·m-2

17. Results
Normalized environmental impacts of Scenario S4 of the building’s service life per 1 m2 of net floor area in 5-year steps
Whole Life-Cycle Use stage

18. Results
Normalized environmental impacts of the building’s service life per 1 m2 of net floor area in 5-year steps

19. Conclusion
Length of the service life has an impact on both total and annual environmental impacts
Omitting repair and replacement scenarios in a building LCA can lead to underestimated results. In case of the assessed building the difference reached up to 22%.
The designed (full) occupancy of the building has slightly higher environmental impacts than “real” occupancy. In case of the assessed building the difference was approximately 5%.

20. Thank you for your attention
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