Steel Residential BuildingThe construction industry is a major contributor to global environmental impacts, consuming significant amounts of non-renewable resources, energy, water, and raw materials. This study conducts a Life Cycle Analysis (LCA) to evaluate the environmental footprint of three different structural systems—Reinforced Concrete (RC), Steel (SC), and Glued-Laminated Timber (GLT) beams—across their full life cycle, from cradle to grave. The analysis focuses particularly on greenhouse gas (GHG) emissions, energy consumption, and air pollution to provide insights for selecting more sustainable building materials.
Methodology and Scope
The assessment covers 100 years of building lifespan, analyzing the embodied carbon, energy usage, and emissions of key pollutants such as CO₂, CH₄, NOx, and SO₂. Three beam alternatives were evaluated with standardized specifications:
- RC Beam: 5000 psi concrete with S355 steel rebar
- SC Beam: S690 steel (W14x26)
- GLT Beam: Softwood lumber with adhesive resins
The study incorporates life cycle inventory (LCI) data for material production, maintenance, and end-of-life processes. Various maintenance schedules were established based on material-specific durability and repair needs.
Key Findings
- GHG Emissions & Energy Use
- RC beams exhibited 10 times higher CO₂ and CH₄ emissions than SC and GLT alternatives.
- SC beams had the lowest emissions but were energy-intensive due to steel production.
- GLT beams showed moderate energy consumption but had lower chemical emissions.
- Life Cycle Costs (LCC)
- RC beams were the most cost-effective (~€3161 per building area).
- GLT beams were moderately priced, while SC beams were the most expensive due to high material and processing costs.
- Multi-Criteria Decision Analysis (MCDA – AHP)
- SC beams ranked highest in environmental performance, followed by GLT beams.
- RC beams had the worst environmental impact despite their low cost.
Conclusion and Recommendations
The study highlights the trade-offs between cost and sustainability in material selection.
- RC beams remain the most economical but contribute significantly to environmental pollution.
- SC beams offer the best environmental benefits but are costly, while GLT beams balance cost and sustainability.
Future improvements could focus on reducing emissions from RC materials, promoting sustainable steel production, and expanding timber resources for construction. The findings serve as a reference for engineers and policymakers in choosing structural materials based on sustainability goals.