Opportunities for material efficiency and green building material choice in the construction of residential buildings in Indonesia. Outcome of a two-year project funded by the German government through the Gesellschaft für Internationale Zusammenarbeit. Presentation given to the closing seminar of the project on 5.Feb.2024 in Jakarta. Material savings and low-carbon construction materials can lead to substantial reduction of #GHG emissions. Stakeholder dialogue was conducted to identifies opportunities, assess barriers, and derive policy recommendations.

1. Material Efficiency for a
Low-Carbon Future in
Residential Construction
in Indonesia
Edgar Hertwich, Fabio Carrer, Sara Amini
Norwegian University of Science and Technology
Ian Hamilton, Harshavardhan Jatkar
University College London
Agus Sari
Landscape Indonesia
Anindya Wulandari
GIZ
IREK II meeting Jakarta
05 February 2024

3. What about the residential building sector in Indonesia?
2020
46Mt
Material production
C02 emissions
2020
323Mt
Material production
Materials
For domestic
consumption only
Yet, exports
generate much more
(80% of cement is
exported)

4. What about the residential building sector in Indonesia?
2020
46Mt
Material production
C02 emissions
2020
323Mt
Material production
Materials
From 2020
to 2050
x2
For domestic
consumption only
m2 of houses
Convergence of
living standards
Yet, exports
generate much more
(80% of cement is
exported)
Population is
increasing and
urbanising

5. What about the residential building sector in Indonesia?
2020
46Mt
Material production
C02 emissions
2020
323Mt
Material production
Materials
From 2020
to 2050
x2
For domestic
consumption only
m2 of houses
Between
2035 -2040
C&D waste
will double up
Construction and
demolition waste
Convergence of
living standards
Yet, exports
generate much more
(80% of cement is
exported)
Population is
increasing and
urbanising
Only 15% recycled

6. Using less material
by design
Enhanced
end-of-life
recovery
More intensive
use of building
space
Scrap
diversion
Product lifetime
extension
Re-use of
components
Efficiency opportunities
across
the entire value chain
Fabrication yield
improvements
Material
substitution

7. Using less material
by design
Enhanced
end-of-life
recovery
More intensive
use of building
space
Scrap
diversion
Product lifetime
extension
Re-use of
components
Efficiency opportunities
across
the entire value chain
Analysis of the material
flows between industries
How the design of
products can change
How much the user
behaviour impacts
Fabrication yield
improvements
Material
substitution

8. RESIDENTIAL ENVIRONMENT MODELLING
❶ Observations and literature data collection
❷ Archetypes modelling

9. 0
500
1000
1500
2000
2500
Steel Cement Wood Concrete Bricks Other
RESIDENTIAL ENVIRONMENT MODELLING
❶ Observations and literature data collection
❷ Archetypes modelling
Kg/m2
❸ Material intensity
Mixed use
residential/commercial
❹ ME design
Single Family
House
Multi purpose
Buildings
Luxury
houses
Informal
houses
ME
ME
ME
11% of the stock
Already bamboo/wood rich, but
discouraged due to fire hazard

10. 0
500
1000
1500
2000
2500
3000
GHG EMISSION SAVINGS POTENTIAL
Mt
CO2
Cumulative GHG emissions 2020-2060 related to material cycle
2891Mt
Projected
495 Mt
Primary
steel
2449 Mt
Cement
and Bricks

11. 0
500
1000
1500
2000
2500
3000
GHG EMISSION SAVINGS POTENTIAL
Mt
CO2
Cumulative GHG emissions 2020-2060 related to material cycle
2891Mt
2256 Mt
Projected Material
efficiency
495 Mt
Primary
steel
2449 Mt
Cement
and Bricks
-627 Mt
Cement
and Bricks
+263 Mt
Wood
-63 Mt
Primary
Steel
-132Mt CO2(*) -532Mt CO2 (*)
(*) Current emission factor
-482 Mt CO2 uptake

12. 0
500
1000
1500
2000
2500
3000
GHG EMISSION SAVINGS POTENTIAL
Mt
CO2
Cumulative GHG emissions 2020-2060 related to material cycle
2891Mt
2256 Mt
1752 Mt
Projected Material
efficiency
Decarbonisation of
material production
40%
of materials
life cycle
emissions
495 Mt
Primary
steel
2449 Mt
Cement
and Bricks
-627 Mt
Cement
and Bricks
+263 Mt
Wood
-63 Mt
Primary
Steel
-132Mt CO2(*) -532Mt CO2 (*)
(*) Current emission factor
-482 Mt CO2 uptake

13. Research process guiding the project
Online Participatory Systems
Mapping Workshop
In-person Priority Action
Mapping Workshop
Online Review
Identify sector
dynamics
Identify barriers
& opportunities
Estimate
timeframe
Identify
solutions for
acceleration
Identify
dissemination
strategy

14. Online Introduction meeting 16th November 2022
1st Online workshop 15th of December 2022
2nd In-person workshop in Jakarta 8th of March 2023
The project was strongly supported by GIZ,
GIZ office in Indonesia, the Ministry of
Environment and Forestry of Indonesia
and UNEP RO.
Broad and comprehensive national
stakeholders’ consultations were
organized within the project - more than
35 participants from relevant ministries,
private sectors, researchers and civil
society organizations.
Indonesia

15. Sector dynamics maps
 Existing and potential
linkages between various
stakeholders in the
constructions industry
 Existing policy instruments
 Key opportunities and
barriers in each country

16. Example of a priority action framework
GOAL 1: USE LOW-CARBON MATERIALS
Stakeholders
A: National, Subnational
and Local Governments
Specific opportunities, barriers and solutions identified for priority actions for each stakeholder
Barriers
• Database of green products is not yet
available
• Product advertising is lacking
• Green labelling/standard is not yet
available for all sustainable materials
• State-led projects are currently
underutilised for demonstrating the
potentials of net-zero transitions
Solutions
• Develop a national Life Cycle
Inventory (LCI) for construction
materials
• Make local material use mandatory.
• Improve green building standards.
• Develop carbon footprint standards.
• Enforce legal requirements for carbon
reduction commitment.
• Collect data related to low-carbon
materials
• Embed the development of
environmentally friendly housing in all
new projects
Opportunities
• Incentives for renewable
energy/local material are
available
• New Capital City is available
as a pilot project
• Environmental-friendly
housing is being developed in
the New Capital City as a pilot
project
Priority Actions
1.1. Provide incentives
for high material
efficiency
1.2. Make commitments
to lowering embodied
carbon emissions of
materials
1.4. Raise awareness of
benefits of low embodied
carbon construction

17. Priority Actions < 5 years 5 - 20 years
GOAL 1: USE LOW-CARBON MATERIALS
G.1.1. Provide incentives for high
material efficiency
G.1.2. Make commitments to
lowering embodied carbon
emissions of materials
 Achieve Key Performance Indicators (KPI) for smart city
development by 2045.
 Mandatory data collection and reporting on low-
carbon materials
 Provide financial support.
 Provide technical support for policy & standards
development.
 Research on low-carbon materials (type, use, and
model project)
 Research on low-carbon materials (type, use, and
model project)
 Facilitate the sector in reducing embodied carbon
content of materials.
 Generate more accurate data.
Tentative timeframes and actions to accelerate the process identified for priority actions
Example of a roadmap

18. 1. Provide incentives for
high material efficiency
2. Make commitments to
lowering embodied
carbon emissions of
materials
3. Promote low embodied
carbon emissions
through public
procurement and pilots
4. Raise awareness of
benefits of low
embodied carbon
construction
1. Boost capacity of
designers
2. Adopt design policies to
promote long building
lifespans
3. Make high quality and
improved
decarbonisation
methods available
4. Build regulations for
disaster and hazard
resilient constructions
5. Optimise construction
techniques
1. Accelerate multiple
pathways to
decarbonisation in the
cement sector
2. Reduce the carbon
footprint of the steel-
making sector
3. Invest in the radical
transformation of
building material
processing (e.g.,
aluminium) and
minimize downcycling
4. Promote the adoption of
bio-based materials
1. Boost capacity of
manufacturers
2. Increase investment in
innovation and R&D
3. Promote fuel switching
and higher efficiencies in
manufacturing of
construction materials
4. Have clear policies on
material decarbonisation
1. Incentivise renovation
and repurposing of
buildings to expand
lifetime
2. Reuse and recycle
building waste at the
end of buildings’
lifetimes
3. Improve deconstruction
processes to enable
reuse and repurposing
4. Target economic
incentives to increase
overall recycling
volumes
GOAL 1:
USE LOW-CARBON
MATERIALS
GOAL 2:
USE LESS MATERIAL BY
DESIGN
GOAL 3:
MATERIAL
DECARBONISATION AND
SUBSTITUTION
GOAL 4:
DECARBONISATION OF
MANUFACTURING
PROCESSES
GOAL 5:
REDUCE WASTE AND
INCREASE REUSE AND
RECYCLING
Goals and actions to achieve a low carbon future

19. Contextualised policy recommendations for each country
ARGENTINA MEXICO INDONESIA
1
2
3
4
5
6
7
Update norms for different climatic conditions
within the country
Collect and maintain accurate data
State to provide technical and financial support
State, academia, and professional organisations
to provide training
Secure investments in R&D
Generate institutional and political agreements
Incorporate building deconstruction into policy
frameworks
Take advantage of the growing sustainable
construction market momentum to generate
monetary and non-monetary incentives
Collect and maintain accurate data
Gradually increase the number of subnational and
local construction laws and regulations
Link the current public mechanisms with the building
certification systems to generate compliance
Support subnational initiatives related to the circular
economy
Leverage the public and private financial mechanisms
Incorporate building deconstruction into policy
frameworks
Leverage on investments in the Capital City
project
Collect and maintain accurate data
State to provide technical and financial
support
The state and academia to provide training
State to invest in R&D
Increase stakeholder consultations
Incorporate building deconstruction into
policy frameworks

20. Ak
Edgar Hertwich
Professor at NTNU
edgar.hertwich@ntnu.no
Harshavardhan Jatkar
Assistant Professor at University College
London
h.jatkar@ucl.ac.uk
Thank you!
Acknowledgments: This work was funded by GIZ and
additional support from the UKRI funded GNCA Project
(NE/T001887/1)
IREK II meeting Jakarta
05 February 2024