Life cycle analysis
Understand how timber supports sustainable, low-carbon design through life cycle analysis (LCA) and carbon accounting.
As the built environment faces increasing pressure to reduce carbon emissions, LCA has become a vital tool for measuring and improving the environmental performance of buildings and materials. Timber, as a renewable, low-carbon building material, plays a key role in creating sustainable, circular buildings from the ground up.
What is life cycle analysis?
LCA is a framework that measures a building material’s environmental impact from start to finish — from raw material extraction (cradle) to construction, use, and end-of-life (grave). It evaluates:
- Energy used and emissions produced
- Material waste and water use
- Opportunities for reuse or recycling
LCA helps professionals make informed design decisions that reduce embodied carbon — the carbon emitted before a building is even used.
Embodied carbon
Embodied carbon accounts for up to 10% of Australia’s total emissions. Reducing it is essential for meeting national climate targets.
EN 15978: LCA in construction – the 4 key stages
The standardised framework for building LCAs, EN 15978, breaks the life cycle into four stages:
- Product stage (A1–A3): Raw material extraction and manufacturing
- Construction stage (A4–A5): Transport and on-site assembly
- Use stage (B1–B7): Maintenance, energy use, repairs
- End-of-life stage (C1–C4): Demolition, recycling or disposal
Optional:
Module D considers benefits beyond the building’s life (e.g. recycled timber reused in another project).
Why timber performs well in LCA
Timber consistently shows strong results in LCA because it:
Stores carbon
Trees absorb CO₂ during growth, and timber products lock in that carbon for the life of the building.
Supports circular design
Timber can be easily reused, recycled, or repurposed, supporting design for deconstruction (DfD) and circular economy strategies.
Has low embodied energy
Producing timber requires less energy than concrete or steel, resulting in lower embodied carbon per cubic metre.
Real world example
Boola Katitjin, WA
This award-winning timber building at Murdoch University showcases the full benefits of LCA and circular design:
- 90% of construction waste was recycled or repurposed
- Carbon-storing mass timber reduced upfront emissions
- Designed for disassembly and future adaptability
Timber and carbon accounting
Carbon accounting involves tracking emissions across all project stages. When paired with LCA, it helps:
- Compare material choices based on carbon footprint
- Set and monitor embodied carbon targets
- Improve sustainability ratings (e.g. Green Star, NABERS)
Key benefits of timber in LCA
| Benefit | Timber advantage |
| Lower embodied carbon | Less energy-intensive than steel or concrete |
| Carbon storage | Sequesters atmospheric CO₂ during tree growth |
| Circularity | Supports reuse, recycling, and design for deconstruction |
| Regulatory alignment | Helps meet evolving standards and green rating requirements |
How professionals use LCA
Architects and Building Designers
- Compare design options based on carbon impact
- Select low-carbon materials like timber over concrete or steel
- Align projects with sustainability rating tools like Green Star or LEED
- Demonstrate environmental leadership to clients and stakeholders
Engineers (Structural, Civil, Mechanical)
- Evaluate structural systems for embodied carbon
- Optimise services design for energy and water efficiency
- Integrate sustainable design targets into early project phases
- Collaborate on low-carbon material substitutions (e.g., CLT in place of concrete slabs)
Quantity Surveyors and Cost Planners
- Create dual carbon-and-cost bills of quantities
- Support value engineering with environmental data
- Advise clients on life cycle costing and long-term savings
- Help projects meet carbon performance goals and gain green certifications
Builders and Construction Managers
- Track and reduce site-related emissions during construction (A4–A5 stages)
- Select and source low-embodied carbon products with verified EPDs
- Minimise waste and maximise reuse/recycling on site
- Document embodied carbon for compliance and reporting
ESG and Sustainability Consultants
- Quantify a building’s total environmental impact
- Model scenarios for emissions reduction
- Prepare documentation for certification and ESG disclosure
- Translate LCA findings into actionable sustainability strategies
Interior Designers and Fitout Professionals
- Select finishes and furniture with lower embodied carbon
- Work with circular materials that support reuse and recycling
- Extend sustainability strategies beyond structure and envelope
- Incorporate modularity and material efficiency into design
Students and Early-Career Professionals
- Build foundational knowledge for sustainable practice
- Understand the full environmental impact of building decisions
- Gain experience using carbon assessment tools and EPDs
- Prepare for a low-carbon future in construction