Identifying and improving environmental hotspots in your EPD

Environmental Product Declarations (EPDs) are essential tools for understanding the environmental footprint of construction products. Most people focus on the carbon footprint typically measured as Global Warming Potential (GWP) but this is only one of many impact categories reported in an EPD. To design truly sustainable products and make informed material choices, we need to consider all categories, as significant hotspots can also appear in areas like water use, air pollution, or resource depletion.

Think of an EPD like a budget sheet for your product’s environmental footprint. It shows how impacts are distributed across stages such as manufacturing, transportation, use phase, and end of life. But just like in finance, not all “spending” is equal; some materials or processes drive disproportionately high impacts. These hotspots become visible when you analyze the EPD data in detail, and they’re not always where you’d expect. Platforms like Emidat make these hotspots transparent by visualizing impacts across all life cycle stages.

This guide offers a practical lens on how to read an EPD, moving beyond carbon to reveal hidden environmental impacts across a product’s full life cycle.

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Focusing only on carbon can lead to blind spots. A product with a low GWP might still have a negative impact on water resources or air quality. To make more informed choices, understanding EPDs means looking beyond GWP to see the full picture. EPDs offer a full-spectrum view of a product’s environmental impact, and seeing that bigger picture is key to truly sustainable design.

These indicators represent the different ‘expense categories’ in your environmental budget*—* each one tells a part of the story.

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• Acidification Potential (AP): Associated with acid rain and soil degradation (mol H⁺ eq). Includes emissions like SO₂ and NOₓ.
• Photochemical Ozone Creation Potential (POCP): Measures contribution to smog and urban air pollution (kg NMVOC eq).
• Ozone Depletion Potential (ODP): Reflects damage to the ozone layer (kg CFC-11 eq).
• Abiotic Depletion Potential – Fossil (ADPF): Tracks use of fossil fuel resources (MJ).
• Abiotic Depletion Potential – Elements (ADPE): Measures depletion of non-renewable minerals (kg Sb eq).
• Water Use (e.g., Water Deprivation Potential, WDP): Captures impact on freshwater availability and ecosystems (m³ deprived).

Takeaway: Low carbon doesn’t always mean low impact. A product can score well on GWP but still have significant effects on acidification, water scarcity, or other environmental pressures.

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Here’s what that looks like in practice: this radar chart shows the environmental footprint of a precast concrete element. Despite its moderate carbon footprint (94.20 kg CO₂e/m²), the product shows notable impacts in categories like water depletion, acidification, and fossil fuel depletion.

The chart illustrates why it’s essential to analyze all impact categories, not just CO₂. A product that appears sustainable in one area may still create stress elsewhere in the system.

To support sustainable product design, we must assess the full life cycle, here shown for the A1–A3 stages (raw material extraction and production), and extend the view through to End-of-Life stages for a complete picture.

Product Declaration (EPD), impacts are broken down by life cycle stage, from raw material extraction to end-of-life.

This guide covers typical hotspots across the full life cycle:

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• Raw materials (A1)
• Transport (A2 & A4)
• Production (A3)
• Assembly or installation (A5)
• Use stage (B1–B7)
• End-of-life (C1–C4)

Hotspot drivers and examples

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• Carbon-intensive inputs like cement clinker, primary steel, polymers, and foams.
• Example: Ordinary Portland Cement (OPC)
• Produces ~803 kg CO₂/ton due to its high clinker content and fossil fuel combustion during calcination.
• Example: Virgin steel rebar
• Emits ~850 kg CO₂/ton, largely from the energy-intensive process of iron ore reduction in blast furnaces.
• Resource-heavy extraction from mining and quarrying can increase ADP and water use.
• Example: Gypsum
• Despite being used in small amounts, gypsum mining can dominate the abiotic depletion of elements (ADPE) contributing up to 76% of the ADPE impact in some cement EPDs.
• High volumes mean that even materials with moderate impacts can add up significantly.
• Example: EPS insulation
• Emits ~3.9 kg CO₂/kg. Its low density and extensive use (e.g. in walls, roofs, and insulation layers) mean it can become a dominant contributor to total GWP and fossil resource use when used in large volumes.

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How to reduce:

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• Use lower-impact alternatives (e.g. Supplementary Cementitious Materials in cement)
• Increase recycled or bio-based content
• Apply lean design principles to reduce total material use

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Hotspot drivers and examples:

• Long distances and heavy loads increase emissions, especially when materials are transported internationally.
• Example: Imported flooring
• In one EPD, transport contributed around 15% of the product’s total GWP largely due to long-distance shipping and road delivery across regions.
• Low-density products require more truckloads to deliver the same mass, increasing emissions.
• Example: EPS or mineral wool insulation
• These materials are bulky but light, so they fill truck space before reaching weight limits. That results in more trips and higher emissions per ton delivered.
• Diesel exhaust contributes to acidification (AP) and smog formation (POCP).
• Example: Long-haul trucking
• For products transported by road, especially over hundreds of kilometers, diesel combustion can drive non-carbon hotspots like acidification and ozone precursor emissions.

How to reduce:

• Source locally
• Optimize truck loading and routing
• Shift to electric or biofuel fleets

Hotspot drivers and examples:

• Energy-intensive processes like kilns, furnaces, and high-temperature operations drive up fossil fuel use and emissions.
• Example: Cement Production
• Heating limestone to ~1,450 °C in rotary kilns not only requires massive amounts of fossil fuel but also releases CO₂ through calcination, making cement one of the largest industrial contributors to GWP.
• Fossil-heavy energy mix significantly raises GWP and contributes to acidification (AP) when electricity or heat comes from coal, oil, or gas.
• Example: Engineered wood flooring
• One EPD showed that 17% of total GWP came from on-site electricity use during sawing, pressing, and drying despite the raw material (wood) being low-carbon.
• Process emissions occur when manufacturing chemically releases pollutants (beyond just energy use).
• Example: Foam insulation (e.g. XPS)
• Certain blowing agents used in production, like HFCs, have high GWP values and can drive upstream and downstream emissions far beyond the material’s mass.
• Auxiliary inputs and waste usually minor contributors, unless rare or toxic substances are involved.
• Example: Catalyst loss in chemical processes
• Some manufacturing uses trace materials (e.g. platinum-group metals) with high abiotic depletion impacts when lost or unrecovered.

How to reduce:

• Switch to renewables
• Improve energy and process efficiency
• Replace high-impact inputs (e.g. HFCs)
• Use recycled materials

• Hotspot drivers and examples:
  
  • Installation energy from tools, cranes, and generators can increase carbon and air pollutant emissions especially on large or equipment-heavy projects.
  • Example: Crane and generator use during installation
  • In one case, the fuel burned during installation accounted for up to 10% of the combined A4 + A5 GWP particularly when diesel-powered equipment ran for extended periods.
  • Ancillary materials like adhesives, grouts, coatings, and tapes may be small in volume but can carry a high environmental footprint.
  • Example: Flooring adhesive
  • In an engineered wood floor EPD, the installation adhesive alone contributed ~9% of total GWP, nearly rivaling the emissions from all factory energy use.
  • Waste generation from off-cuts, packaging, and leftover material increases the effective footprint of every kg of raw input especially if landfilled or incinerated.
  • Example: Drywall installation
  • Around 20% of drywall material may end up as off-cut waste on-site, meaning the upstream A1–A3 impacts of that material are effectively repeated for every discarded section.
  • On-site emissions like VOCs from solvents or adhesives, or particulate matter from cutting/sanding, can contribute to smog formation (POCP) and local health impacts.
  • Example: How to reduce:
  • Products containing solvents or reactive chemicals can emit ozone precursors, adding to POCP even after manufacturing is complete.
  How to reduce:
  • Use prefabrication to reduce on-site waste
  • Offer guidance on low-impact installation methods
  • Improve equipment efficiency
  • Promote smart packaging and recycling

This stage captures in-use emissions, energy consumption, maintenance needs, and replacement impacts.

While many construction materials have minimal use-phase impacts, some products flip that pattern.For example, electronic systems such as HVAC units or lighting may have comparatively smaller A-stage impacts, but generate significant emissions during use due to electricity consumption or refrigerant leakage. In these cases, the B stages dominate the environmental footprint.

There are also exceptions within construction. Precast concrete components, for instance, may carry relevant B-stage impacts depending on maintenance frequency, repair requirements, or thermal performance over time. These cases are less common but important to consider.
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Hotspot drivers and examples:

• Operational energy use from lighting, HVAC, or other active systems often dominates the use-phase footprint especially in commercial or services buildings.
• Example: HVAC systems
• Heating and cooling systems can account for more than 50–80% of total life cycle GWP in some buildings, especially when powered by fossil-fuel-based electricity.
• Refrigerant leakage from cooling and heating systems can have a much higher GWP than operational energy itself especially if high-GWP gases like HFCs are used.
• Example: ACs and heat pumps
• Leakage of refrigerants gases such as R-410A or R-134A during use or maintenance can surpass the embodied emissions of the unit. One kg of leaked R-410A equals ~2 tons of CO₂e.
• Maintenance and replacement cycles contribute to long-term material and energy impacts especially when components have short lifespans or require frequent repair.
• Example: Cladding repainting
• External timber or coated metal panels may require repainting every 5–10 years, adding repeated B2 emissions that accumulate over time.
• Water use during operation, especially for sanitary systems and appliances, drives Water Deprivation Potential (WDP) and energy use (for heating).
• Example: Plumbing fixtures
• Toilets, faucets, and showers especially older models can account for a significant portion of B7 impacts, particularly in multi-residential buildings.

❗️Note: For many construction materials (e.g. concrete, timber, insulation), B-stage impacts are negligible or zero.

How to reduce:

• Use durable, low-maintenance materials
• Choose energy-efficient HVAC and lighting systems
• Specify low-GWP refrigerants and smart controls
• Design modular components for easy repair or upgrade
• Install water-saving fixtures and appliances

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Hotspot drivers and examples:

• Demolition energy (C1) can be significant when dealing with heavy or mechanically fastened building components, especially those that require cutting or specialized equipment.
• Example: Heavy concrete panels
• Removing large precast or in-situ concrete elements often involves high fuel use from breakers, saws, or cranes, contributing to demolition-phase GWP and particulate emissions.
• Waste processing (C3) can add energy and material burdens particularly when recycling is energy-intensive or when contamination complicates recovery.
• Example: Steel recycling
• While steel is highly recyclable, melting it in electric arc furnaces (EAFs) still consumes significant electricity, often contributing to C3 GWP unless renewable energy is used.
• Disposal impacts (C4) arise from landfilling or incineration, especially with synthetic or composite materials that do not degrade or emit harmful byproducts.
• Example: EPS/XPS insulation
• If incinerated, these materials release CO₂ and potentially toxic VOCs. If landfilled, they can persist for decades without decomposing occupying volume and risking leachate.

How to reduce:

• Design for easy deconstruction and reuse
• Choose recyclable materials with clear end-of-life paths
• Avoid composites or glued assemblies that prevent recycling
• Sort materials on-site to maximize recovery

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To design truly sustainable products, don’t just track CO₂. Instead, analyze the full environmental budget. Start by targeting the biggest impact drivers, then iterate across all categories. Every decision from materials to transport should support sustainable outcomes across the full footprint.
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Your Sustainable Strategy:

• Eliminate the worst hotspots first
• Invest in lower-impact materials and smarter processes
• Optimize for total environmental performance, not just carbon

Want to turn your EPD data into actionable insights? Emidat helps you spot environmental hotspots instantly, from carbon to water use and beyond.

👉 Generate your first radar chart in with us.