Environmental assessment of the Urban Mining and Recycling (UMAR) unit by applying the LCA framework

Efstathios Kakkos1, Felix Heisel2, Dirk Hebel2, Roland Hischier1

1 Technology & Society Laboratory, Empa, St. Gallen, Switzerland2 Sustainable Construction, Faculty of Architecture, KIT Karlsruhe, Germany

Agenda

1

1. Introduction

2. General approach

3. Life Cycle Assessment

4. Results

5. Conclusion & Outlook

1.1 Introduction – Issues in the building sector

Construction & operation of

buildings

42% of total energy

consumption

33% oftotal EU waste

30% of total water

consumption

35% of total GHG emissions

50% of total mined

materials

Data from: European Commission (2011) Roadmap to a ressource efficient Europe

New sustainablebuilding conceptsrequired.

2

1.2 Introduction – One possible solution (Urban Mining)

“A young discipline that identifies the building stock as a unified system and waste(whether from the dismantling of houses or from other sources) merely as a transitionalstate from which something new can emerge.”

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Material Store

1.3 Introduction – Advantages of Urban Mining

Stocked materials quantities comparable to or exceed those in naturalstocks.

Secondary material stream through recovery and remanufacturing / reuseof urban mined materials.

Reduction of GHG emissions through reduced energy input and avoidedwaste treatment processes.

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1.4 UMAR unit

5

Copyright Werner Sobek with Dirk E. Hebel and Felix Heisel (2018)

RecyclableReusableCompostable

1.5 UMAR unit – Innovative materials

6

Glass plate HDPE plate Recycled bricks

Denim Insulation

Mushroom plate

1.6 UMAR unit – Design for Disassembly

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2.1 General approach - 2-step process description

Comparison of the woodenindividual UMAR elements withthe conventional elements usedin Swiss construction practice.

Comparison of UMAR unit with ahypothetical concrete one, withthe same size, same assumedlifetime, roughly same energyconsumption.

1. Building element level

2. Building level

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Type of ElementConventional

Elements

Outside wall

Sand lime Brick

wall

Concrete wall

Inside wall Gypsum dry wall

Floor Concrete floor

3.1 LCA – Standard & Software

Standard: EN15804 Sustainabilty of construction works

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3.2 LCA - framework

Building element level

Compare the most importantwooden UMAR unitelements with the respectiveconventional ones.

Building level

Assess and compare theannual impacts of the Umarand concrete unit over theentire 60-year service life.

1 m2 of building elementunder examination.

1 m2 of gross floor area perone-year of buildinglifetime.

(Non-Renewable) Cumulative Energy Demand (CED) - MJGlobal Warming Potential (GWP) - kg CO2-eqSwiss Ecopoints - UBP

1. Goal and scope

1a. Functionalunit

3. Impact assessment

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1b. System boundaries

2. Life cycleInventory

As presented in the previous slide.

Product stage (A1-3)All stages reported inprevious slide.

3.3 LCA - Basic assumptions

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Natural resources have been used as a starting point (firstlifecycle of materials).

Replacement of all wooden parts considered for UMAR unit +windows. Only window replacement considered for theconcrete unit.

Stage D: Direct reuse of all UMAR materials. Recycling ofConcrete and steel, Heat recovery from incineration ofwooden materials and insulation + reuse of all othermaterials for concrete unit.

4.1 Results - Building element level

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0

25

50

75

100

Um

ar

Bri

ck

Co

ncr

ete

Um

ar

Gyp

sum

Um

ar

Co

ncr

ete

Um

ar

Bri

ck

Co

ncr

ete

Um

ar

Gyp

sum

Um

ar

Co

ncr

ete

Um

ar

Bri

ck

Co

ncr

ete

Um

ar

Gyp

sum

Um

ar

Co

ncr

ete

Outside wall Insidewall

Floor Outside wall Insidewall

Floor Outside wall Insidewall

Floor

CED GWP UBP

% im

pac

t

4.2 Results - Building level

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-50

-25

0

25

50

75

100

UMAR Concrete UMAR Concrete UMAR Concrete

CED GWP UBP

% im

pac

t

Production stage (A1-A3) Transport to building site (A4)

Construction (A5) Replacement (B4)

Operational energy (B6) Deconstruction / Demolition (C1)

Incineration / Disposal (C2-C4) Reuse / Recovery potential (D)

5.1 Summary & Outlook

Next steps

Modelling of further lifecycles of UMAR materialsshould be considered.

Embeddedness andevaluation of the UMARconcept at city, national oreven a global level.

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Key Points

Reduction of primary energyused, global warming potentialand overall environmentalimpact.

Reuse / Recovery potential ofUMAR materials higher thanthat of the convential ones.

This study would not have been possible without fundings from the Technology and Society Lab (TSL) of Empa, and the Karlsruhe Institute of Technology (KIT).

Thank you for your attentionEfstathios Kakkos«Advancing Life Cycle Assessment» Group

Technology & Society Lab, Empa, St. Gallen (Switzerland)

Efstathios.Kakkos@empa.ch