Carbon Footprint vs. Life Cycle Assessment: What is the Difference?

As sustainability expectations grow across energy, construction, and manufacturing sectors, so does the pressure to demonstrate the carbon and environmental impact of materials, products, and assets. 

But not all assessments are created equal. 

You may have heard of Carbon Footprinting and Life Cycle Assessment (LCA). They are often used interchangeably, but they are not the same. 

Carbon Footprint: A Piece of the Puzzle 

A carbon footprint is a subset of a full LCA. It focuses on one impact category: climate change, by quantifying greenhouse gas (GHG) emissions and expressing them in kilograms or tonnes of CO₂-equivalent (CO₂e). These are calculated using Global Warming Potential (GWP) metrics, which reflect each gas’s relative contribution to climate change over a defined timeframe, typically GWP100 (100-year horizon). 

Life Cycle Assessment (LCA): The Full Picture 

A Life Cycle Assessment (LCA) evaluates a product or system’s potential environmental impacts across multiple impact categories, not just climate change. It covers the entire life cycle: from raw material extraction and manufacturing, through use, and ultimately to disposal or recycling (cradle-to-grave). It can also include Module D to account for benefits such as reuse, recycling, or energy recovery, often referred to as a cradle-to-cradle approach. 

Here is what you need to know: 

Understanding Terminology

LCA Modules Explained – What Do A1 to D Actually Mean? 

To bring structure and consistency to assessments, carbon footprints and LCAs often follow the EN 15804 / EN 15978 modular framework: 

Module	Stage	What It Covers
A1–A3	Product Stage	Raw materials, transport to factory and manufacturing
A4–A5	Construction Stage	Transport to site and installation / assembly
B1–B7	Use Stage	Use, maintenance, repair, replacement, operational energy, water
C1–C4	End-of-Life Stage	Deconstruction, transport, recycling and final disposal
D	Beyond System Boundary	Benefits from recycling, reuse or energy recovery

Lifecycle Boundaries: Cradle-to-Gate? Cradle-to-Grave? Cradle-to-Cradle? 

These terms define how much of the full life cycle of the product is measured:

Boundary	What it Covers	Used For
Cradle-to-Gate	Raw materials to factory gate (A1–A3)	Fast carbon footprint estimates
Cradle-to-Site	Adds transport & installation (A1–A5)	Construction product LCAs
Cradle-to-Grave	Full life cycle, manufacturing & use through to disposal (A1–C4)	Whole-life carbon assessments
Cradle-to-Cradle	Adds reuse/recycling credits (A1–C4 + D)	Circular economy modelling

Example: If you are comparing the embodied carbon of concrete vs. low-carbon alternatives, a cradle-to-gate view might be enough. But if you are claiming one performs better over time or is more recyclable, you need cradle-to-grave or cradle-to-cradle. 

LCA Covers Other Impact Categories Too 

A Life Cycle Assessment (LCA) gives a multi-dimensional view of a product’s sustainability profile. While a carbon footprint focuses only on the climate change impact category, a full LCA includes a range of additional environmental impacts, some of which are outlined below: 

Impact Category	What it Measures
Climate change	Greenhouse gases (CO₂, CH₄, etc.)
Ozone depletion	CFCs and HCFCs damaging the ozone layer
Acidification	Emissions causing acid rain (SO₂, NOₓ)
Eutrophication	Nutrient runoff polluting rivers and oceans
Photochemical smog	VOCs and NOₓ forming ground-level ozone
Resource depletion	Use of fossil fuels, minerals, and water
Human toxicity	Potential health effects from emissions and materials
Ecotoxicity	Impact on aquatic and terrestrial ecosystems

So Which One Do You Need? 

If you want to:	Use this:
Estimate potential carbon impacts quickly and compare products	Carbon Footprint
Quantify full environmental trade-offs and inform design decisions	Full LCA
Make third-party verified environmental claims (e.g. for EPDs)	Full LCA

Source: https://www.ramboll.com/en-gb/insights/decarbonise-for-net-zero/which-life-cycle-assessment

References

What you need to know about Embodied Carbon - GRESB 

LCA Stages Matter When Tracking Embodied Carbon - Browning Day