What is an LCA? 3 life-cycle assessment examples

1. Production and construction

This initial stage involves creating and assembling the materials used to construct a building. It encompasses various processes, each contributing to the building’s overall environmental impact.

• Raw Material Extraction: Extracting natural resources for construction, like minerals, metals, aggregates, wood, and more.

• Manufacturing: Raw materials are transformed into construction products through manufacturing processes that consume energy and release emissions and other wastes.

• Transportation: Materials are transported from extraction sites to manufacturing and construction facilities.

• Construction: Building construction involves various activities, from site preparation and foundation work to assembly and installation.

2. Use phase

The use phase encompasses the building’s operational activities, which occur once the building is occupied. This phase is marked by energy consumption, water usage, ongoing maintenance, and other operational activities.

• Energy Consumption: The operation of a building requires energy for various purposes, such as lighting, heating, cooling, and powering electrical equipment. The source of this energy can determine the building’s carbon footprint.

• Water Usage: Occupants of buildings consume water for sanitation, hygiene, and various activities. Excessive water consumption can strain local water resources and contribute to water scarcity.
• Maintenance: Sustainable maintenance practices can extend the life of building materials, reduce waste generation, and minimize the need for new resources.

3. End-of-Life

The end-of-life stage involves the decommissioning and disposal of the building once it reaches the end of its useful life.

Let’s dive into a hypothetical life cycle assessment example. Imagine you are an architect tasked with designing a new office building for a client. You are committed to creating a sustainable structure that minimizes environmental impact. You could perform an LCA early in the design phase to guide your material and design choices to achieve this goal.

You start by collecting design data from your BIM software. This data includes the building’s layout, dimensions, and materials. You then enter this information into the LCA software, automatically generating an initial report.

At this point you can explore different material options for the building’s structure, envelope, and finishes. You could consider traditional materials like concrete and steel and alternative sustainable materials like cross-laminated timber (CLT) and recycled steel. Each material choice has an environmental profile, which considers carbon emissions, impacts to the soil, water, consumption of primary energy, and more.

Using an LCA software, you can analyze the environmental impacts of each material option and choose a material based on that data. For example, cross-laminated timber and recycled steel both have lower carbon footprints than traditional concrete and steel. An LCA would allow you to see the actual value of that lower carbon footprint, make your material decisions based on data, and present the sustainability and cost benefits to stakeholders.

In this example, performing an LCA early in the design phase enables you to make informed material decisions which lead to a more sustainable and eco-friendly building design.

One Click LCA’s Carbon Designer 3D enables architects to estimate embodied carbon with just building type and size. Optimize, compare, and visualize the carbon performance of design alternatives before you start drawing.

Life-cycle assessment example 2, for developers: Assessing operational energy efficiency

In this scenario, imagine you are a real estate developer who plans to construct a new apartment complex in an urban area. You are committed to creating energy-efficient buildings that minimize operational carbon emissions.

Your goal for this LCA is to choose the highest level of energy efficiency for the apartment complex, while at the same time limiting embodied carbon. The scope includes evaluating design alternatives for building orientation, insulation, glazing, HVAC systems, and lighting. The primary focus is on reducing energy consumption without increasing embodied carbon.

Your initial energy analysis shows that a passive solar design and energy-efficient HVAC system produce the lowest operational emissions over the building’s lifespan. Using an LCA, you can further assess how much embodied carbon each material choice will add to the overall structure. This will give you a more detailed and complete picture of the total carbon impact, and lets you choose the most efficient operational system that also has a low embodied carbon footprint.

You can also evaluate the cost implications of implementing energy-efficient design alternatives, compare upfront costs, maintenance expenses, and potential energy savings over the building’s lifespan. The aim is to find design options that reduce carbon emissions and offer a good return on investment.

In this example, performing an LCA during the early design phase allows you to assess different design alternatives and choose an energy-efficient approach while also minimizing embodied carbon.

One Click LCA’s comprehensive LCA tool and database allows developers to effectively measure and reduce the carbon impact of their projects. Learn more here.

Life-cycle assessment example 3, for engineers: XPS versus cellulose insulation

Now, imagine you are an engineer tasked with designing an energy-efficient and environmentally sustainable office building. Your goal is to assess the environmental impact of different insulation materials for the building envelope.

While looking at insulation, you identify two options: high-performance extruded polystyrene (XPS) insulation and cellulose fiber insulation. XPS is known for its superior thermal properties, potentially leading to higher operational energy efficiency. However, initial research indicates that XPS manufacturing processes contribute to high embodied carbon emissions. Though offering lower thermal performance, cellulose fiber insulation is expected to have lower embodied carbon due to its renewable and recycled content.

Using an LCA software, and considering all life cycle stages, you may find that the operational energy savings promised by XPS insulation are significant, but are overshadowed by the high embodied carbon of XPS. Whereas cellulose fiber insulation might be the more favorable option when considering the overall carbon footprint, despite its lower thermal performance.

In this scenario, the LCA process allows you to make an informed decision by considering the trade-offs between operational energy savings and embodied carbon emissions. Taking the time to better understand the role of various types of insulation in the overall carbon footprint allows you to choose a material that contributes to the building’s environmental sustainability and reflects a comprehensive understanding of the building’s life cycle impacts.

One Click LCA provides engineers access to thousands of environmental product declarations, making the job of comparing different products simple and easy. Learn more about EPDs and the role they play in a comprehensive LCA.