Selection of Sustainable Building Material using LCADesign
ToolSupply Chain and Operations Management Assignment
Seongwon Seo1,a, Selwyn Tucker1,b and Michael Ambrose1,c
1 CSIRO Sustainable Ecosystems, 37 Graham Rd (PO Box 56), Highett, Victoria 3190,
Australia
a[email protected], b[email protected], c[email protected]
ABSTRACT
Manufacture, construction and use of buildings and building materials make a significant
environmental impact internally, locally and globally. But it is not easy to deliver
information to make adequate holistic decisions considering the whole life cycle of building.
Decisions in sustainable building integrate a number of strategies during the design,
construction and operation of building projects. Selection of sustainable building materials
represents an important strategy in the design of a building.
The Australian Cooperative Research Centre for Construction Innovation (CRC CI) funded
development of an evaluation tool, LCADesign, for automated building environmental life
cycle assessment (LCA). LCADesign is built on an ICT software platform, acting as a hub, to
integrate outputs of 3D object oriented CAD models, a national Life Cycle Inventory (LCI)
environmental database and recognised Life Cycle Impact Assessment (LCIA) indicators to
report comparative performance across building planning, design, quantity survey and
checking applications.
This paper describes methodological approach for LCADesign and illustrates with an
example for environmental life cycle assessment (LCA) for building materials.
KEYWORDS: Life cycle assessment, Building evaluation tool, Decision making
1. INTRODUCTION
Design decisions regarding the selection of less environmental impact building components
need careful consideration during the building design process. Careful building design and
materials selection can substantially reduce environmental impacts (Kim and Rigdon,1998;
DEH, 2006). In order to assist building designers or developers in choosing more sustainable
options, a number of tools have been developed in the past decade to assess the impact of
choice of materials on energy consumption or other specific environmental impact of
buildings. Most of the tools have limitations and weaknesses and in a review of such tools,
many common problem areas have been identified (Seo, 2002). The weaknesses include
having a narrow focus, lacking in-depth assessment, needing professional assessors, requiring
time-consuming data input, considering minimal economic criteria and lacking transparency
in weighting environmental indicators (Todd et al, 2001).
Successful implementation of a tool capable of performing the required tasks involves not
only the development of computer software and related databases but paying considerable
attention to the needs of the potential users. The technological advances made in producing a
unique and versatile tool potentially form a paradigm shift in assessing the environmental
impacts of buildings but only if the implementation addresses the problems faced by those
who currently assess the environmental impacts of building and their materials (Watson and
Jones, 2004). A useful approach to achieve high performance design is to assess materials
and design features simultaneously to obtain a full picture of impacts of a building on
environment at the design stage.
A new integrated eco-assessment tool, LCADesign, was developed to fulfil the above
requirement by addressing the needs identified by the stakeholder requirements for building
evaluations. This paper gives a brief overview of the tool, which enables building design
professionals to make informed and fast decisions about a building or its products, as well as
its application to a case study building to demonstrate how a tool such as LCADesign can be
used in sustainable building design processes and material selection, to satisfy the
requirements of building design professionals and commercial industry.
2. FRAMEWORK FOR LCADESIGN
2.1 Integrated approach
An integrated environmental evaluation tool, called LCADesign was developed funded by
Cooperative Research Centre for Construction Innovation (CRC CI), Australia for automated
building environmental life cycle assessment (LCA). LCADesign is an acronym for Life
Cycle Assessment (LCA) with Computer Aided Design (CAD). It is built on an ICT software
platform, to integrate outputs of 3D object oriented CAD models, a national Life Cycle
Inventory (LCI) environmental database and recognised Life Cycle Impact Assessment
(LCIA) indicators to report comparative performance across building planning, design,
quantity survey and checking applications.
| Australian Local LCI data Rail Tr ansport g eneral freight 354 4 0.4800 901 4 Mixture f or Cem ent M aking 1.4400 kg Life Cycle Inventory |
| Input |
3D CAD Objects
| Key indicators Environmental performance Economic performance Various performance indicators |
| Analysis |
For Building
1
2 3 4
612
Air emission dust in processing 7500.0000 mg
Air emission CO in processin g 370000.0000 mg
Air emission CO2in processing 500000.0000 mg
Air emission SOx in processing 8000.0000 mg
Solid W ast e Mineral W aste
818 0.2646 kg
8xx Coal use in Aus tralia 1.6262 MJ
878 0.3900 MJ
884 0.1870 MJ
888 1.5000 MJ
354
2
Road Transport A 18+ t onne 0.0019 v km
Natural gas use in Aus tralia Natural gas use in Australia
Diesel Us e in Au stralia
Burn coal feed s tock as fuel
Other Oil Use in Australia
9015 Dry Process Cem ent Clinker F ormation
Co
de Input operation Quant it y Unit
0.0707 kg
Automated Take-Off
Connection Info.
Material DB
| Improvement |
| Eco-efficient Design process Database Selection Comparison of different designs |
Figure 1 Essential steps for LCADesign tool
The principal aim of LCADesign is to integrate building environmental assessment in a 3D
CAD model to avoid any manual transcription of data from one step to another in evaluation
processes. A schematic diagram of LCADesign is shown in Figure 1. LCADesign is divided
into three main parts which comprise the followings key steps:
• Input
o Creating a 3D CAD model of a building,
o Using the dimensional information in the 3D CAD model to automatically
estimate quantities of all materials in the building,
• Analysis
o Estimating all material and gross building environmental burdens by
factoring each material quantity with results of their emissions generation and
resource depletion from a comprehensive database of a wide range of
building materials,
o Calculating a series of environmental indicators based on Life Cycle Analysis,
and
• Improvement
o Providing facilities to undertake detailed analysis of alternative designs and
benchmarking over time to facilitate designers’ creation of buildings with
least environmental impact considering their service delivery requirements.
Information for LCADesign flow seamlessly from the 3D CAD model to the evaluation stage
without interruption or intervention from the designer or environmental assessor. Thus the
designer can obtain almost instant feedback on whether the current building design under
development is likely to produce a better environmental outcome.
LCADesign uses Life cycle assessment (LCA) methodology to assess the environmental
impact of a product (including buildings) from raw material acquisition to product
manufacture and replacement. This includes components that are replaced in part or in whole
over the life of a building, depending on the usage patterns, refurbishment or occupancy.
Quantification of the environmental impacts of a product and the derivation of clear measures
involves many complex tasks requiring applied physical chemistry and process engineering
knowledge, numerous detailed observations and extensive data collection that must be
transposed into simple measured units to compile model datasets. It involves the systematic
ordering of many considerations in extensive detail for subsequent condensation into
numerous types of calculations resulting in environmental indicators based on causal
relationships contributing to key impacts.
The environmental indicators available in LCADesign comprise:
• Life cycle impact assessment (LCIA with Eco-indicator 99);
• Embodied energy (EE);
• Embodied water (EW);
• Carbon emissions (CE);
• Total greenhouse gas emissions (GHGs); and
• Recycled mass (RM).
With such indicators, builders, designers and building owners can view their building’s
environmental performance and make efforts to reduce its impact.
2.2 Benefits
From the perspective of the general user, a software tool is the front end to the environmental
analysis of buildings. The “Analysis” is the basic “unit of work” of the system and provides
the user interface into the results of the environmental analysis of one or more commercial
building designs. Benefits of LCADesign include:
• Automated environmental assessment direct from 3D CAD drawings;
• Choice of environmental impact and performance measures;
• Detailed design evaluation;
• Assessment of buildings at all levels of design analysis; and
• Comprehensive graphical and tabular outputs.
LCADesign provides environmental assessors with the capability to test alternative scenarios.
This means that all the attributes of all the objects drawn in the 3D CAD model can be
substituted and investigated, drilling down to identify the specific impacts or indicators of
these variations. This is a role for an environmental expert who does not need any 3D CAD
experience.
3. APPLICATION EXAMPLE
Melbourne City Council Building (CH1) was selected to show how LCADesign can be used.
The building is about 35 years old and is being considered for refurbishment. This building
has four floors of car park for 230 cars, a retail area of 400m2, offices on seven floors each of
1070 m2 per floor totalling 7490 m2 and roof level plant room; in all 7668 m2. The structure
of this building comprises reinforced concrete slabs supported by primary and secondary
beams and concrete encased steel columns for the car-parks and concrete encased steel
columns and steel edge beams on the perimeter for the office floors.
The environmental impact of the materials used in the building was analysed for the example
building using LCADesign. Eco-indicator-99 was chosen as the main environmental
indicator. For the example building, the resulting impacts for the whole building using
LCADesign are shown in Figure 2. .
| 40.7 |
| 2 |
| Shell |
0
20
40
60
80
100
120
140
Example Building
Ecopoints/m2
0 3.5
10
20
30
40
50
60
70
80
90
Shell
Ecopoints/mSuperstructure
Substructure
| Other | Sets | Scenery |
| Services Shell | Site |
13.7
| 18.7 | |
| 4.1 | |
| 32.8 | |
| 2.9 | |
| 10 20 30 40 50 60 70 80 90 |
|
| Roof Internal Walls Internal Screen External Doors |
Internal Doors External Walls Columns |
4.9
0
Superstructure
| E uctu |
| copoints/m2 |
| Superstr |
| 79.6 |
Windows Upper Floors Staircases
83.1 Figure 2. Environmental impact by layers and further breakdown for example building
As seen in the left hand side of Figure 2, the example building is classified into several layers
of longevity of built components, which distinguishes several layers as shell, services, scenery,
set, and site. Total environmental impact of the building was 127 ecopoints/m2 for the Ecoindicator-99 indicator. Of the building layers, more than half the environmental impact was
contributed by the shell part which was further divided into two parts as super-structure and
sub-structure, with by far the largest contribution to the Eco-indicator value for the shell being
the superstructure as might be expected. The superstructure component can be further broken
down into elemental groups, consisting of several elements (columns, internal and external
walls, internal and external doors, windows, staircases, roof etc), with the largest
contributions being from upper floors (structure), followed by the internal walls and the
external walls.
By becoming aware of which building materials and elements of a building have the lowest
environmental impact, architects or building designers can encourage the marketing of
sustainable buildings by specifying the more environmentally friendly products and
redesigning buildings to reduce the largest element contributors. For example, in the example
building, a small reduction in use of materials in the upper floor structure could reduce the
overall impact by more than the whole contribution by the roof.
One of the possible options to reduce environmental impact can be considered as using
recycled materials. However, recycling may not always be the most environmentally friendly
option. Thus, building materials containing recycled contents should be evaluated in a
manner consistent with a quantitative assessment of the overall environmental impacts.
Steel is the most commonly recycled building material, in large part because it can be easily
separated from construction debris. In this example building, the potential for using recycled
content was restricted mainly to reinforcement bars (up to 99% recycled) and 7% fly ash
concrete which is popularly used in Australia.
Figure 3 shows the environmental impact comparison for the same building with alternative
building materials which have recycled content in the superstructure part of the building. By
replacing the non-recycled material components with those materials with recycled contents
(99% recycled reinforcement bars and 7% fly ash concrete) in the superstructure part, the total
environmental impact was reduced by 19% to 103.1 ecopoints/m2.
| 83.1 |
| 40.7 |
| 23.8 |
76.2
0
20
40
60
80
100
120
140
Example Building Alternative
Ecopoints/m2
Other
Sets
Scenery
Services
Shell
Site
Figure 3. Comparison of Eco- indicator 99 for the example building and alternative
There are also different indicators which might be concerned by different purposes. These
indicators comprise embodied energy, embodied water, and greenhouse gas emissions etc.
The potential to calculate and use these indicators are a result of the detailed underlying life
cycle inventory of building materials and can be selected according to the user’s needs. Some
of these indicators are shown in Figure 4 for the example building.
Five different indicators for both the example building and the same building constructed
completely of lower environmental impact (alternative) materials (including recycled content)
are shown in Figure 4 for the same superstructure part assessed in the earlier figures. The
lower environmental impact materials were chosen as representative of what is now available
a rather than those materials with the lowest environmental impact.
| 0 20 40 60 80 100 120 140 Ecopoints/m2 |
0 10000 20000 30000 40000 50000 60000 70000 MJ/m2 |
Alternative Embodied Energy 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 ve MLitre/m2 Example Building Other Sets Scenery Services |
0 50 100 150 200 250 300 350 400 450 500 g/m2 |
Shell kg CO2/m2 -2500 -2000 -1500 -1000 -500 0 500 1000 1500 |
Site |
| Example Building Alternative EcoIndicator 99 |
Alternative Recycled Mass Example Building |
Alternative Greenhouse Gas Emission Example Building |
AlternatiEmbodied Water
Example
Building
Figure 4. Comparison of the example building and the same constructed of lower
environmental impact products for different indicators
The analysis of this example building suggests that a wide range of possible outputs illustrates
how useful the breakdowns are in determining which components have benefited most from
choosing less environmental impact materials and which have not.
Selection of sustainable building materials frequently requires difficult decisions since it is
carried out considering a range of different environmental indicators. To deal with this
difficulty effectively, an integrated evaluation tool, LCADesign that supports decision makers
for building environmental performance has been developed and is a significant contributor to
stakeholder needs in that it provides:
• Objective detailed and comparative assessment rather than subjective assessments;
• Real time detailed design appraisals and evaluations with tool automatic take-off
CAD;
• Generation of meaningful comprehensive graphics, tables and reports;
• Comparing alternatives at all level of design analysis, and
• Environmental assessment of building’s development from cradle to construction.
However, environmental considerations need not be the only factor when selecting building
materials. The key consideration is the material’s appropriateness for the intended function as
well as the cost of their manufacture. As seen in Figure 4, embodied energy for alternative
building was much higher than for the initial example building. This is because the wool
carpet was used as finished flooring to reduce the environmental impact of the scenery part in
the alternative building. Even though traditional wool carpeting is non-toxic and less
hazardous for building occupants, the embodied energy is higher than existing one made from
petroleum products (It is also a lower cost product).
While most of the environmental performance indicators do trend in the same direction for
alternative products, care must betaken to ensure that the decisions are not made from a single
viewpoint identified by using only one performance indicator. Thus, there will be other
indicators such as costs and/or social aspects which might exist in conflict relationships when
attempting to deliver the best decisions for sustainable buildings and/or building materials.
4. CONCLUSION
While considering various criteria that influence environmental sustainablility of building,
Building material selection is more difficult. To deal with this difficulty effectively,
LCADesign has been developed as an integrated eco-assessment tool to analyse, value and
compare environmental impacts of design alternatives of the building and building material.
The example building demonstrated that an integrated tool which utilises a Life Cycle
Inventory of building materials enables design practitioners to make timely informed
decisions on reducing environmental burdens of building materials as well as facilitating selfassessment from an environmental point of view at the design stage rather than at the postconstruction stage. While a range of performance indicators are readily available in such a
tool, use of a single focus performance indicator may mislead the designer in choosing the
materials which produce the lowest environmental impact of the building as a whole.
5. ACKNOWLEDGEMENT
This paper has been prepared from research undertaken by the CRC for Construction
Innovation based in Australia.
6. REFERENCES
Department of Environment and Heritage (DEH), 2006. ESD Design Guide for Australian
Government buildings, Australian Government Department of the Environment and Heritage,
February.
Kim, J. and Rigdon, B., 1998. Sustainable Architecture Module: Qualities, Use, and
Examples of Sustainable Building Materials. Sustainable Architecture Compendium, National
Pollution Prevention Center, University of Michigan.
Seo, S., 2002. International review of environmental assessment tools and databases, Report
2001-006-B-02, Cooperative Research Centre for Construction Innovation, Brisbane.
Todd, J. A., Crawley, D., Geissler, S. and Lindsey, G., 2001. Comparison assessment of
environmental performance tools and the role of the Green Building Challenge, Building
Research and Information, 29 (5), 324-335.
Watson, P. and Jones, D.G., 2004. Environmental assessment for commercial buildings:
Stakeholder requirements and tool characteristics, CSIRO, Report 2001-006-B-01 Part 2