Saona Island Building Life-Cycle Assessment: Embodied Carbon, Material Selection and Sustainable Coastal Construction

Introduction

A building's environmental impact begins long before its first occupant arrives. Extracting raw materials, manufacturing cement and steel, transporting products, constructing foundations and operating electrical and mechanical systems all require resources and energy. Maintenance, renovation and eventual demolition create additional impacts throughout the building's life.

For an island destination such as Saona Island in the Dominican Republic, building design should consider more than initial construction cost and appearance. Material availability, transportation distances, coastal exposure, maintenance requirements, energy consumption and long-term durability can influence the environmental performance of a building.

Building life-cycle assessment (LCA) provides a systematic way to evaluate these impacts. Instead of examining only one construction material or one stage of a project, it considers the building as a complete system over a defined period.

This guide explains how life-cycle assessment can support sustainable building decisions for a hypothetical coastal project on Saona Island. It covers embodied carbon, operational emissions, environmental product declarations, material selection, structural design, coastal durability and whole-life carbon reporting.

It is an engineering and planning framework, not a claim that a particular building has been assessed or that specific low-carbon construction products are available on the island.

1. What Is Building Life-Cycle Assessment?

Life-cycle assessment is a method for evaluating the environmental impacts associated with a product, process or system throughout its life cycle.

For a building, the assessment can examine:

• Extraction of raw materials
• Manufacturing of construction products
• Transportation to the construction site
• Construction and installation
• Building operation
• Maintenance and repair
• Replacement and refurbishment
• Deconstruction or demolition
• Waste processing and final disposal

The purpose is to understand where environmental impacts occur and how design decisions can reduce them.

A building that uses less material during construction may have lower initial impacts, but if it requires frequent repairs or consumes substantially more energy during operation, its total life-cycle impact may be higher.

Life-cycle assessment therefore encourages decisions based on long-term performance rather than one isolated stage.

2. Life-Cycle Assessment and Whole-Life Carbon

Two related concepts are important in sustainable construction.

Life-cycle assessment

LCA can examine multiple environmental impact categories, including:

• Global warming potential
• Acidification
• Eutrophication
• Ozone depletion
• Resource use
• Water consumption
• Waste generation

The categories and indicators depend on the assessment method and applicable standards.

Whole-life carbon assessment

Whole-life carbon assessment focuses specifically on greenhouse gas emissions and removals associated with a building throughout its life cycle.

It can include:

• Embodied carbon from materials and construction
• Operational carbon from building use
• Carbon associated with maintenance and replacement
• End-of-life impacts
• Relevant benefits and loads beyond the building's system boundary

Whole-life carbon is therefore a focused carbon assessment, while a broader LCA can investigate a wider range of environmental impacts.

3. Understanding Embodied Carbon

Embodied carbon refers to greenhouse gas emissions associated with construction materials and building processes.

It can arise from:

• Mining and extraction of raw materials
• Processing and manufacturing
• Fuel and electricity used in factories
• Transportation of products
• Construction equipment and installation
• Maintenance and replacement
• Demolition and waste processing

Concrete

Cement production is an important source of embodied carbon in concrete because the manufacture of Portland cement involves energy use and chemical reactions that release carbon dioxide.

Concrete's total environmental impact also depends on aggregate production, transport, mix design, supplementary cementitious materials, curing and service life.

Steel

Steel production can involve substantial energy and process emissions. Its environmental profile depends on the production route, electricity supply, recycled content, manufacturing efficiency and transport.

Aluminium

Aluminium production can be energy-intensive. Recycled aluminium may have a different environmental profile from primary aluminium, but the actual result depends on the supply chain and product specification.

Timber

Timber products can store biogenic carbon during their service life, but their assessment needs to consider forest management, processing, transport, treatment, service life and end-of-life scenarios.

A material should not automatically be described as low-carbon based only on its category. Its actual environmental performance depends on reliable product-specific or appropriately representative data.

4. Understanding Building Life-Cycle Stages

Building assessments commonly organise environmental impacts into defined life-cycle modules.

Product stage: A1–A3

This stage includes:

• A1: Raw material supply
• A2: Transport to manufacturing
• A3: Manufacturing

For example, the production impacts of cement, reinforcement steel, glass and insulation can be included here.

Construction process stage: A4–A5

This stage includes:

• A4: Transport of construction products to the project site
• A5: Construction and installation processes

For an island project, transportation assumptions deserve careful attention. The route, transport mode, shipment size, loading efficiency and local delivery arrangements can influence the result.

Use stage: B1–B7

This stage can include:

• B1: Use
• B2: Maintenance
• B3: Repair
• B4: Replacement
• B5: Refurbishment
• B6: Operational energy use
• B7: Operational water use

A coastal building may require particular attention to the replacement and maintenance of exposed components.

End-of-life stage: C1–C4

This stage can include:

• C1: Deconstruction or demolition
• C2: Transport
• C3: Waste processing
• C4: Disposal

Beyond the system boundary: Module D

Module D can report potential benefits or loads beyond the assessed building life cycle, such as certain future reuse or recycling scenarios.

These modules help make an assessment transparent. They also prevent a project from reporting only the stages that make its environmental performance appear favourable.

5. Defining the Functional Unit and Assessment Boundary

A reliable LCA needs a clear description of what is being assessed.

Functional unit

The functional unit defines the building service being compared.

For example, two alternative designs might be compared based on providing the same usable floor area, function, occupancy capacity and expected service life.

Simply comparing one tonne of concrete with one tonne of timber does not necessarily provide a fair comparison if the materials perform different structural functions.

Reference study period

The assessment should define the period over which building performance is evaluated.

The period should be appropriate to the project, the applicable methodology and the intended comparison.

System boundary

The system boundary identifies which activities and life-cycle stages are included.

If transportation, maintenance or replacement is excluded, the exclusion should be explained and reported.

Consistent comparison

Alternative designs should be assessed using comparable assumptions for:

• Functional performance
• Building area
• Structural requirements
• Indoor environmental conditions
• Assessment period
• Maintenance and replacement
• Energy and water use
• End-of-life scenarios

A consistent basis helps prevent misleading conclusions.

6. Environmental Product Declarations

An Environmental Product Declaration (EPD) provides standardised environmental information about a construction product based on life-cycle assessment.

An EPD can report environmental indicators for products such as concrete, cement, steel, insulation, flooring and other building materials.

Why EPDs matter

An EPD can help designers and engineers compare products using documented environmental information rather than broad marketing claims.

It may include:

• Product description
• Declared or functional unit
• Product category rules
• Manufacturing information
• Environmental impact indicators
• Life-cycle modules covered
• Data quality and verification information

Product-specific versus generic data

Product-specific EPD data can provide more relevant information when the product and manufacturing conditions match the project requirements.

Generic or industry-average data may be needed when product-specific information is unavailable.

The assessor should record the data source and its limitations.

Important comparison rule

Two EPDs should not be compared casually if they use different product category rules, declared units, boundaries, assumptions or reporting periods.

A valid comparison requires consistent technical performance and compatible assessment conditions.

7. Building Material Selection for a Coastal Island Context

Material selection for a coastal building should consider both environmental impacts and technical suitability.

Concrete

Concrete is widely used in foundations, slabs, columns and beams.

Potential environmental improvements can include:

• Efficient structural design
• Optimised concrete quantities
• Appropriate use of supplementary cementitious materials
• Reduced construction waste
• Local or efficiently transported aggregates where suitable
• Longer service life through appropriate durability design

Any alternative concrete mix must meet strength, workability, durability and specification requirements.

Reinforcement steel

Steel selection should consider:

• Structural performance
• Recycled content information
• Manufacturing route
• Corrosion protection
• Availability of product-specific EPDs
• Transportation requirements

The lowest initial carbon value is not useful if the product cannot meet the structural and durability requirements.

Timber

Timber may be suitable for selected structural, architectural or interior applications.

Its suitability depends on:

• Structural grade
• Moisture conditions
• Biological durability
• Fire requirements
• Treatment and coating
• Responsible sourcing
• Connection design
• Maintenance requirements

In coastal environments, detailing and moisture management are particularly important.

Masonry and blocks

Masonry products should be assessed based on their production process, transport, strength, thermal performance, durability and maintenance requirements.

Efficient wall layouts and appropriate thicknesses can also influence material quantities.

Insulation and glazing

Insulation and glazing can affect operational energy demand. Their embodied impacts should be compared with the expected operational benefits over the building's life.

The correct solution depends on the building's climate, orientation, ventilation strategy, occupancy and cooling requirements.

8. Transportation and Supply-Chain Impacts

Transportation can influence the embodied carbon of construction materials.

For an island project, the assessment should examine the actual or proposed supply chain rather than assuming every material is locally sourced or imported.

Relevant factors include:

• Production location
• Distance to port or distribution centre
• Shipping mode
• Vessel or vehicle type
• Freight loading efficiency
• Port handling
• Final delivery distance
• Packaging and material protection

A simple transport-emissions calculation can be expressed as:

Transport emissions = Freight mass × Transport distance × Emission factor

Where:

• Freight mass is measured in tonnes
• Transport distance is measured in kilometres
• The emission factor is expressed in kilograms of CO₂ equivalent per tonne-kilometre

The emission factor must match the transport mode and appropriate data source.

This simplified calculation is an example of the method, not a measured Saona Island transport result.

9. Operational Carbon and Building Energy Performance

Operational carbon is associated with energy and other resources consumed during the building's use.

Depending on the building, this may include:

• Air conditioning
• Ventilation
• Lighting
• Water heating
• Refrigeration
• Pumps
• Elevators
• Appliances
• Other building services

Passive design

Passive design can reduce energy demand by responding to local climate conditions.

Possible design strategies include:

• Building orientation
• External shading
• Appropriate window-to-wall ratios
• Natural ventilation where conditions permit
• Roof insulation
• Solar-control glazing
• Daylight optimisation
• Thermal comfort planning

Passive strategies must be evaluated against humidity, rain, wind, insects, security and indoor air-quality needs.

Efficient building systems

Energy-efficient air-conditioning, lighting, fans, pumps and controls can reduce operational energy consumption.

Equipment selection should consider performance under the expected operating conditions, maintenance requirements and replacement cycles.

Renewable electricity

On-site renewable electricity may reduce operational emissions where suitable resources, installation conditions and maintenance arrangements exist.

However, an LCA should use transparent assumptions about energy generation, system lifetime, replacement and the electricity displaced.

10. Water Use and Life-Cycle Impacts

Building water systems can contribute to environmental impacts during operation.

A water-related assessment may consider:

• Potable water consumption
• Water heating
• Pumping energy
• Rainwater collection
• Efficient fixtures
• Leak detection
• Reuse of suitable non-potable water
• Wastewater treatment arrangements

Water-saving fixtures can reduce demand, but the assessment should consider the full system, including installation, maintenance and user behaviour.

Rainwater harvesting and water reuse should be assessed for technical suitability, water quality, storage capacity and maintenance requirements.

11. Coastal Durability and Material Service Life

Durability is a major factor in whole-life environmental performance.

A building material that requires frequent replacement may create additional manufacturing, transport and installation impacts.

Coastal exposure can involve:

• Salt-laden air
• High humidity
• Wind-driven rain
• Wetting and drying cycles
• Chloride exposure
• Corrosion risk
• Solar radiation
• Biological growth

Reinforced concrete durability

Reinforced concrete design should consider exposure conditions, concrete quality, cover, crack control, curing and appropriate detailing.

Chloride ingress and reinforcement corrosion can reduce service life if the structure is not designed and maintained appropriately.

Metal components

Metal fixtures, fasteners, railings and external equipment may require suitable material selection and corrosion protection.

Building envelope

Roofing, windows, sealants, coatings and external finishes should be selected with their expected exposure and maintenance needs in mind.

Durability and carbon trade-offs

A product with a slightly higher initial embodied impact may perform better over the full assessment period if it lasts longer and requires fewer replacements.

This is why whole-life comparison is more informative than initial material comparison alone.

12. Structural Design and Material Efficiency

Structural design affects the quantity of concrete, steel, masonry and other materials used in a building.

Material efficiency can be improved through:

• Appropriate structural grids
• Efficient load paths
• Rational span selection
• Avoiding unnecessary structural complexity
• Accurate quantity estimation
• Efficient reinforcement detailing
• Design coordination
• Appropriate prefabrication where feasible

However, reducing material quantities must never compromise structural safety, serviceability, fire safety or durability.

A life-cycle assessment should compare technically equivalent designs rather than reward a lighter structure that fails to meet required performance.

13. Retrofit Versus New Construction

A life-cycle assessment can help determine whether an existing building should be renovated, extended or replaced.

Demolition and new construction may involve substantial material production, transportation and construction impacts.

Retrofit may preserve useful structural elements and avoid some new-material demand. However, an older building may have poor energy performance, significant repair needs or limitations that make renovation less suitable.

A fair comparison should include:

• Existing structural condition
• Required repairs
• Energy performance
• Expected remaining service life
• New-material quantities
• Operational energy changes
• Maintenance requirements
• End-of-life assumptions

The best option depends on the building and the required service—not on a universal rule that renovation or new construction is always better.

14. Calculating a Building's Whole-Life Carbon

A whole-life carbon assessment combines data from relevant building elements and life-cycle stages.

A simplified expression is:

Whole-life carbon = Product-stage impacts + Construction-stage impacts + Use-stage impacts + End-of-life impacts + Relevant beyond-boundary reporting

A more detailed assessment should account for the applicable modules and reporting rules rather than treating the expression as a complete calculation standard.

Elemental assessment

The building may be divided into elements such as:

• Substructure
• Superstructure
• External walls
• Roof
• Internal walls
• Finishes
• Building services
• External works

For each element, the assessor records quantities, environmental data, replacement assumptions and relevant transport or construction processes.

Material-level calculation

A simplified product-stage calculation is:

Material carbon impact = Material quantity × Embodied carbon factor

For example, if an illustrative project uses 10 tonnes of a material with an assumed factor of 200 kg CO₂e per tonne, the calculated product-stage impact would be 2,000 kg CO₂e.

This is an illustrative arithmetic example only. It is not a real material factor or a Saona Island building result.

Reporting intensity

Results may also be reported per unit of floor area, such as kilograms of CO₂ equivalent per square metre, provided the area definition and assessment boundary are clearly stated.

15. Life-Cycle Assessment Tools and Data Sources

Several resources can support building LCA.

ISO standards

ISO 14040 provides principles and a framework for life-cycle assessment.

ISO 14044 specifies requirements and guidance for carrying out and reporting LCA studies.

Building-level assessment frameworks

EN 15978 provides a methodology for assessing the environmental performance of buildings over their life cycle. The applicable current edition and national adoption should be checked before project use.

RICS whole-life carbon assessment

The Royal Institution of Chartered Surveyors publishes a whole-life carbon assessment standard for the built environment. Its second edition provides a structured methodology for reporting carbon across life-cycle stages.

Environmental Product Declarations

EPDs can provide product-level environmental information that supports material comparisons.

LCA software

Professional LCA tools can help manage:

• Building quantities
• Material inventories
• Environmental datasets
• Life-cycle modules
• Replacement scenarios
• Impact calculations
• Reporting

The choice of tool does not replace the need for reliable project data, appropriate assumptions and competent review.

16. A Proposed LCA Framework for a Saona Island Building

A hypothetical building assessment could follow these stages.

Stage 1: Define the project

Record the building's intended function, floor area, structural system, occupancy assumptions and assessment period.

Stage 2: Develop design alternatives

Prepare technically equivalent options for structural systems, envelope materials, finishes and building services.

Stage 3: Prepare the quantity inventory

Extract material quantities from drawings, specifications and bills of quantities.

Stage 4: Collect environmental data

Use verified EPDs where available, supplemented by suitable generic datasets when necessary.

Stage 5: Model transportation

Identify the proposed supply chain and calculate transport impacts using documented distances, modes and emission factors.

Stage 6: Estimate use-stage impacts

Assess energy and water demand using suitable building-performance assumptions and relevant local data.

Stage 7: Estimate maintenance and replacement

Identify components likely to require maintenance, repair or replacement during the assessment period.

Stage 8: Assess end-of-life scenarios

Document demolition or deconstruction assumptions, material processing, transportation and disposal.

Stage 9: Compare alternatives

Identify which design choices create the largest impacts and where realistic reductions can be achieved.

Stage 10: Report uncertainty

Explain missing data, assumptions, limitations, sensitivity and any excluded modules.

The assessment should be updated as the project design and material specifications become more detailed.

17. Common LCA Mistakes to Avoid

Comparing materials without equivalent performance

A kilogram of one material may not provide the same structural or functional service as a kilogram of another.

Ignoring transportation

Using a generic material factor without considering the actual supply chain can misrepresent project impacts.

Excluding maintenance

Materials with different service lives cannot be compared fairly if replacement is ignored.

Using incompatible EPDs

Different boundaries, declared units or product category rules can make direct comparison misleading.

Reporting only embodied carbon

Operational energy, water use and end-of-life assumptions may materially affect the whole-life result.

Using unsupported local assumptions

Project teams should not invent local material sources, transport distances, electricity factors or facility capabilities.

Treating Module D as an automatic credit

Potential future recycling or reuse benefits should be reported according to the chosen methodology and kept transparent rather than used to conceal impacts within the assessed building boundary.

18. Civil Engineers' Role in Sustainable Building LCA

Civil engineers can contribute to whole-life assessment from concept design through operation.

Their work may include:

• Structural system comparison
• Concrete and steel quantity optimisation
• Material specification
• Foundation design
• Durability assessment
• Construction sequencing
• Quantity take-offs
• Procurement support
• Quality assurance
• Maintenance planning
• End-of-life design considerations

Engineers can help connect environmental calculations with structural safety, functionality, cost and service-life requirements.

Frequently Asked Questions

1. What is building life-cycle assessment?

Building LCA is a systematic method for evaluating the environmental impacts of a building across defined stages, from raw-material extraction and construction to operation, maintenance and end-of-life.

2. What is embodied carbon?

Embodied carbon is the greenhouse gas impact associated with materials and construction processes, including extraction, manufacturing, transport, installation, maintenance, replacement and end-of-life activities within the assessment boundary.

3. What is the difference between embodied carbon and operational carbon?

Embodied carbon is associated with building materials and processes. Operational carbon is associated with energy and other resource use during building operation, depending on the assessment scope.

4. What is an Environmental Product Declaration?

An EPD is a standardised document reporting environmental information about a product based on life-cycle assessment and applicable product category rules.

5. Why does transportation matter in an island building assessment?

Material supply may involve several transport stages. Distance, transport mode, freight loading and delivery arrangements can influence the environmental impact of construction products.

6. Does a low-carbon material always make a building sustainable?

No. A building must also meet structural, safety, durability, functional and operational requirements. The full life cycle should be considered.

7. Can life-cycle assessment compare renovation and new construction?

Yes. LCA can compare alternative building scenarios when they provide equivalent functions over a consistent assessment period and use transparent assumptions.

8. Which standards are useful for building LCA?

ISO 14040 and ISO 14044 provide general LCA principles and requirements. Building-level methods such as EN 15978 and professional guidance such as the RICS whole-life carbon assessment standard can support built-environment assessments.

Conclusion

Building life-cycle assessment offers a practical way to understand the environmental impacts of construction beyond the initial building phase. For a hypothetical coastal project on Saona Island, it can help engineers and designers evaluate material choices, transportation, embodied carbon, operational energy, water use, maintenance and end-of-life scenarios.

The most useful assessment begins early, uses reliable environmental data and compares designs that provide equivalent performance. It should also account for the durability demands of coastal exposure and the practical realities of material supply and maintenance.

Sustainable construction is not simply a matter of choosing a product labelled green. It requires a whole-building approach that balances environmental performance, structural safety, durability, cost and long-term function.

By integrating life-cycle assessment into design and procurement, building teams can make more transparent decisions and identify opportunities to reduce environmental impacts throughout the life of a building.