Timber construction significantly reduces building life cycle environmental impact

Why It Matters

This research highlights the critical role of material selection in the environmental performance of buildings. Designers and engineers can leverage these findings to make informed decisions that contribute to more sustainable construction practices and reduce the overall ecological footprint of the built environment.

Key Finding

Buildings constructed with more timber, especially when timber is used for structural and architectural elements, have a significantly lower environmental impact over their entire life cycle.

Key Findings

• Increasing the amount of timber in building construction decreases initial embodied energy and global warming potential.
• Timber-based buildings showed lower total energy consumption and global warming potential over their 60-year lifespan compared to concrete and steel alternatives.
• Innovative timber structural systems and increased use of timber in architectural elements further amplified these environmental benefits.

Research Evidence

Aim: To quantify the life cycle energy use and global warming potential of multi-storey office buildings constructed with different primary materials (concrete, steel, and timber variations).

Method: Life Cycle Assessment (LCA) modelling

Procedure: Four similar six-storey office building designs were modelled: one with concrete structure, one with steel structure, one with an innovative timber structure (LVL), and one with an enhanced timber structure including architectural features. The LCA considered embodied energy, maintenance, transport, operational energy, and end-of-life scenarios (landfill vs. reuse).

Context: Commercial building construction

Design Principle

Embrace renewable and sustainably sourced materials in construction to minimize embodied energy and operational carbon emissions throughout a building's life cycle.

How to Apply

When designing new buildings, conduct a comparative LCA early in the design process to evaluate the environmental performance of different material choices, with a strong consideration for timber-based solutions.

Limitations

The study is based on modelled buildings and specific New Zealand sourcing and end-of-life scenarios, which may vary in other geographical contexts. Operational energy consumption was kept similar across all models, potentially masking other operational differences.

Student Guide (IB Design Technology)

Simple Explanation: Using wood instead of concrete or steel for building parts makes the building much better for the environment over its whole life.

Why This Matters: Understanding how different materials affect the environment helps you make responsible design choices that reduce pollution and conserve resources.

Critical Thinking: To what extent do regional differences in material sourcing, manufacturing processes, and waste management infrastructure affect the comparative environmental benefits of timber versus concrete or steel construction?

IA-Ready Paragraph: This research demonstrates that the selection of construction materials significantly influences the environmental footprint of multi-storey buildings. By modelling concrete, steel, and various timber-based structures, the study found that increasing timber content, particularly through innovative structural and architectural applications, leads to substantial reductions in embodied energy and global warming potential over the building's life cycle. This supports the adoption of timber as a more sustainable alternative in construction.

Project Tips

• When choosing materials for your design project, research their environmental impact using LCA data.
• Consider innovative uses of materials, like advanced timber systems, to improve sustainability.

How to Use in IA

• Reference this study when justifying material choices based on environmental impact, particularly when comparing timber to traditional materials like concrete or steel.

Examiner Tips

• Demonstrate an understanding of life cycle assessment and its importance in evaluating the true environmental cost of design choices.

Independent Variable: ["Primary construction material (Concrete, Steel, Timber, TimberPlus)","Extent of timber use (structural vs. structural + architectural)"]

Dependent Variable: ["Life cycle energy use","Global warming potential (GWP)","Embodied energy of materials"]

Controlled Variables: ["Building size and storeys (six-storey, 4,200m2)","Building lifetime (60 years)","Operational energy consumption (low and similar across models)","Construction time (predicted similar)"]

Strengths

• Comprehensive life cycle assessment including end-of-life scenarios.
• Comparison of multiple material options and innovative timber designs.
• Modelling based on an actual building type.

Critical Questions

• How do the costs associated with innovative timber construction compare to traditional methods?
• What are the long-term durability and maintenance considerations for timber in different climates compared to concrete and steel?

Extended Essay Application

• Investigate the embodied energy and carbon footprint of different materials for a specific design project, using LCA principles to justify material selection for sustainability.

Source

Environmental Impacts of Multi-Storey Buildings Using Different Construction Materials · University of Canterbury Research Repository (University of Canterbury) · 2009