Life Cycle Assessment reveals embodied energy and operating energy are key drivers of building sustainability.

Why It Matters

Understanding the primary contributors to a building's environmental footprint allows designers and engineers to prioritize interventions. Focusing on embodied and operating energy can lead to more impactful sustainable design choices, reducing overall resource depletion and pollution.

Key Finding

The energy used to create building materials and to run buildings is the biggest factor in their environmental impact. While carbon footprint is often measured, more comprehensive environmental metrics are needed, and social impact assessment tools require development. The lifespan and material quality of buildings are also critical but often underestimated.

Key Findings

• Embodied energy and operating energy are major contributors to the environmental and socio-economic objectives of the construction industry.
• The 'carbon footprint' is the most commonly used indicator, but a wider range of environmental impact categories is needed to avoid trade-offs.
• Social life cycle assessment (S-LCA) requires methodological improvements for better application in the building industry.
• The service life of buildings is often approximated, with the quality and durability of materials frequently overlooked in LCA.

Research Evidence

Aim: To critically review and analyze studies on residential buildings' sustainability performance using life cycle assessment (LCA) and identify research gaps.

Method: Literature Review

Procedure: Researchers systematically searched multiple academic databases for peer-reviewed articles published between 2009 and 2019 related to sustainability in residential buildings. They analyzed approximately 807 articles, focusing on the application of life cycle assessment tools and key impact indicators.

Sample Size: 807 research articles

Context: Residential building design and construction

Design Principle

Holistic Life Cycle Assessment: Evaluate a product's environmental and social impact from raw material extraction through disposal, considering energy, materials, and social factors.

How to Apply

When designing a new building or renovating an existing one, conduct a life cycle assessment that quantifies embodied energy, operational energy, and other relevant environmental impacts. Consider the social implications of material sourcing and construction processes, and specify materials known for their durability to extend the building's service life.

Limitations

Many studies focused primarily on LCA tools rather than comprehensive sustainability outcomes. The quality of materials and their long-term durability were often not fully integrated into assessments. Social LCA methodologies are still developing.

Student Guide (IB Design Technology)

Simple Explanation: When designing buildings, think about all the energy used to make the materials and all the energy the building will use when people live in it. These are the most important things for making a building sustainable. Also, consider how people are affected and how long the building will last.

Why This Matters: This research highlights that true sustainability in buildings isn't just about one factor like carbon emissions. It's a complex balance of environmental, economic, and social considerations over the entire life of the building, with energy being a major focus.

Critical Thinking: Given the emphasis on embodied and operational energy, how can designers effectively balance these with other crucial aspects like cost, aesthetics, and occupant well-being?

IA-Ready Paragraph: This research indicates that embodied energy and operational energy are critical factors in assessing the sustainability of residential buildings. My design project aims to address these by [mention specific design choices, e.g., selecting low-embodied energy materials and incorporating passive solar design principles] to minimize the overall environmental footprint.

Project Tips

• When researching materials, look for data on embodied energy and expected lifespan.
• Consider using online LCA tools to estimate the environmental impact of your design choices.
• Think about the social impact of your design – who benefits, who might be negatively affected?

How to Use in IA

• Use the findings on embodied and operational energy to justify material choices or energy-saving strategies in your design project.
• Discuss the limitations of focusing solely on carbon footprint and propose the use of broader impact categories for your design evaluation.

Examiner Tips

• Demonstrate an understanding of the trade-offs between different sustainability goals (environmental, social, economic).
• Critically evaluate the limitations of common sustainability metrics like carbon footprint.

Independent Variable: ["Material selection (influencing embodied energy)","Building design features (influencing operational energy)"]

Dependent Variable: ["Total life cycle energy consumption (embodied + operational)","Environmental impact indicators (e.g., carbon footprint, resource depletion)"]

Controlled Variables: ["Building size and type","Climate zone","Occupancy patterns","Service life duration considered"]

Strengths

• Comprehensive review of a decade of research.
• Identifies key drivers of building sustainability.
• Highlights methodological gaps in current assessment tools.

Critical Questions

• How can the 'social sustainability' aspect be more effectively quantified and integrated into design decisions?
• What are the most practical and accessible LCA tools for designers working on smaller-scale projects?

Extended Essay Application

• An Extended Essay could investigate the embodied energy of locally sourced vs. imported construction materials for a specific building type, comparing their overall environmental impact.
• Another EE could explore the development of a simplified framework for assessing the social sustainability of building designs.

Source

A Review of Residential Buildings’ Sustainability Performance Using a Life Cycle Assessment Approach · Journal of Sustainability Research · 2019 · 10.20900/jsr20190006