Report on a Harmonized Dataset of High-Resolution Embodied Life Cycle Assessment Results for Buildings in North America

Introduction and Background

Buildings contribute significantly to global environmental impacts, accounting for approximately 37% of global energy and process-related carbon dioxide (CO₂) emissions as of 2022. This includes 27% from building operations and 10% from building materials and construction. With global building construction projected to grow substantially throughout the 21st century, addressing the environmental impacts of buildings is critical for sustainable development and climate action.

The Sustainable Development Goals (SDGs), particularly SDG 11 (Sustainable Cities and Communities), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action), emphasize the importance of reducing environmental impacts associated with urban development and construction. Life Cycle Assessment (LCA) is increasingly used by building design practitioners to evaluate these impacts, yet harmonized and publicly accessible datasets, especially in North America, remain limited.

Objectives

This report presents a novel, high-resolution dataset of building design characteristics, life cycle inventories, and environmental impact assessment results for 292 building projects across the United States and Canada. The dataset aims to support sustainable development by enabling detailed analysis, benchmarking, and policy formulation aligned with the SDGs.

Dataset Overview and Significance

Dataset Composition

• Includes harmonized, non-aggregated LCA model results across life cycle stages, building elements, and materials.
• Contains over 90 building design and LCA features to assess material use and environmental impacts.
• Data were crowd-sourced from designers conducting LCAs of real-world building projects.
• Represents nearly 5 million square meters of newly constructed floor area.

Alignment with Sustainable Development Goals

• SDG 11 (Sustainable Cities and Communities): Enables analysis of building impacts to foster sustainable urban development.
• SDG 12 (Responsible Consumption and Production): Supports resource efficiency by providing detailed material use data.
• SDG 13 (Climate Action): Facilitates reduction of embodied carbon and other environmental impacts in building construction.

Methodology

Data Acquisition

1. Established partnerships with 30 architecture, engineering, and construction firms across North America.
2. Collected three types of data per project:
   • Project Metadata: Building characteristics and LCA modeling parameters.
   • Life Cycle Inventory (LCI) Data: Material quantities and service life.
   • Life Cycle Impact Assessment (LCIA) Results: Environmental impacts per material.
3. Used standardized data entry templates and user guides to ensure methodological alignment and data consistency.
4. Approved LCA tools included Tally LCA and One Click LCA, compliant with international standards.

Data Preparation and Harmonization

• Pre-processed and validated metadata for completeness and consistency.
• Harmonized LCA results syntax, structure, and semantics to create a flexibly harmonized dataset.
• Reclassified building elements using Omniclass Table 21 for consistency across different LCA tools.
• Developed a novel building material classification system aligned with North American CSI MasterFormat and Environmental Product Declarations (EPDs).
• Addressed biogenic carbon reporting by excluding uptake and emissions from GWP totals to ensure comparability.
• Finalized dataset with anonymization, quality assurance, and removal of inconsistent or incomplete projects.

Data Records and Structure

Dataset Files

• buildings_metadata.xlsx: Contains project metadata and LCA parameters for each building.
• full_lca_results.xlsx: Includes detailed LCI and LCIA results per material and life cycle stage.
• data_glossary.xlsx: Defines and describes dataset features, units, and mappings.
• material_definitions.xlsx: Lists material groups and types with descriptions and classifications.

Data Accessibility and Usage

The dataset is openly accessible via Figshare and mirrored on a public GitHub repository, facilitating reuse and extension by researchers, designers, and policymakers. The detailed, non-aggregated structure enables high-resolution analysis of environmental impacts and material use, supporting evidence-based decision-making aligned with the SDGs.

Technical Validation

Methodological Validity

• Dataset completeness is high, with less than 7% missing values in metadata and less than 1% in LCA results.
• Building element reclassification reduced undefined elements from 23% to less than 1% of total GWP, enhancing data quality.
• Material classification condensed over 1,500 raw material names into 117 unique types within 22 groups.
• Data contributors reviewed and validated their submissions, ensuring accuracy and reliability.

Environmental Impact and Material Use Consistency

• Embodied Carbon Intensity (ECI) for new construction projects ranges from 84 to 2160 kgCO₂e/m², consistent with existing studies.
• Material Use Intensity (MUI) ranges from 130 to 4907 kg/m², with concrete, steel, gypsum, masonry, and wood as dominant materials.
• Life cycle stages A1–A3 contribute the majority of embodied carbon impacts.
• Comparisons with European and regional datasets show reasonable consistency, supporting dataset validity.

Limitations

• Variability in LCA modeling methods and assumptions may affect result accuracy.
• Dataset focuses primarily on design-stage models, not as-built measurements.
• Renovation projects are less represented and should be used cautiously.
• Data anonymization and rounding may slightly affect precision but preserve confidentiality.

Usage Notes and Recommendations

Data Analysis Guidance

• Users should consider project types and physical scopes when comparing data to ensure functional equivalence.
• Full LCA results enable detailed material- and stage-specific analyses; aggregation may be needed for some applications.
• Normalization metrics include constructed floor area, gross floor area, occupants, and residential units, supporting diverse analyses.
• Missing data are denoted as “NULL” and should be handled appropriately in analyses.
• Outliers exist but are within plausible ranges; users may filter or apply robust statistics as needed.

Data Access and Future Development

• The dataset is available on Figshare and GitHub for public use and extension.
• Future updates may include additional projects, metadata, and higher resolution data.
• Open-source code for data preparation and analysis is provided to facilitate reproducibility and further research.

Conclusion

This harmonized, high-resolution dataset of embodied life cycle assessment results for buildings in North America represents a significant advancement in supporting the Sustainable Development Goals related to sustainable cities, responsible consumption, and climate action. By providing detailed, comparable, and openly accessible data, it empowers designers, researchers, policymakers, and industry stakeholders to analyze environmental impacts, set performance targets, and promote sustainable building practices. The dataset fills critical gaps in existing data resources and serves as a foundation for future research and policy development aimed at reducing the environmental footprint of the built environment.

1. Sustainable Development Goals (SDGs) Addressed

• SDG 11: Sustainable Cities and Communities – The article discusses the environmental impacts of buildings and construction, emphasizing sustainable design and construction practices to reduce emissions and environmental pressures.
• SDG 12: Responsible Consumption and Production – The focus on life cycle assessment (LCA), material use intensity (MUI), and embodied impacts (EI) relates to sustainable management and efficient use of natural resources.
• SDG 13: Climate Action – The article highlights the importance of reducing greenhouse gas emissions from building operations and construction materials to mitigate climate change.
• SDG 6: Clean Water and Sanitation – Indirectly addressed through the discussion of environmental pressures such as eutrophication and water emissions from building materials.
• SDG 9: Industry, Innovation and Infrastructure – The development and harmonization of LCA datasets and methodologies support innovation in sustainable infrastructure and industrial processes.

2. Specific Targets Under the Identified SDGs

1. SDG 11 – Target 11.6: Reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management. The article’s focus on reducing embodied impacts and environmental burdens of buildings aligns with this target.
2. SDG 12 – Target 12.2: Achieve the sustainable management and efficient use of natural resources. The article’s emphasis on material use intensity and life cycle inventories supports this target.
3. SDG 12 – Target 12.4: Achieve environmentally sound management of chemicals and all wastes throughout their life cycle. The life cycle impact assessment (LCIA) results including acidification, eutrophication, smog formation, ozone depletion, and non-renewable energy demand relate to this target.
4. SDG 13 – Target 13.2: Integrate climate change measures into national policies, strategies, and planning. The dataset supports policymakers in setting performance targets and benchmarking embodied carbon, aiding climate action policies.
5. SDG 9 – Target 9.4: Upgrade infrastructure and retrofit industries to make them sustainable, with increased resource-use efficiency and greater adoption of clean and environmentally sound technologies. The harmonized LCA datasets and methodologies contribute to this target.

3. Indicators Mentioned or Implied in the Article

• Embodied Carbon Intensity (ECI): Measured as the total global warming potential (GWP) per floor area (kgCO₂e/m²), used to benchmark and compare environmental impacts of buildings.
• Material Use Intensity (MUI): Measured as the mass of materials used per building floor area (kg/m²), enabling tracking of resource use.
• Life Cycle Impact Assessment (LCIA) Midpoint Indicators: Including acidification potential (AP), eutrophication potential (EP), smog formation potential (SFP), ozone depletion potential (ODP), and non-renewable energy demand (NRED), which measure various environmental pressures.
• Life Cycle Inventory (LCI) Data: Quantities and types of materials used in buildings, reported per life cycle stage and building element.
• Biogenic Carbon Storage: Reported as stored carbon (kgCO₂e) in bio-based materials, separated from fossil carbon emissions.
• Normalization Metrics: Environmental impacts and material use intensities normalized by constructed floor area (CFA), gross floor area (GFA), number of occupants, or residential units for comparability.

These indicators enable measurement of progress towards the targets by providing detailed, harmonized, and comparable data on environmental impacts and resource use in buildings.

4. Table of SDGs, Targets, and Indicators

Source: nature.com