Looking Beyond Energy Efficiency
By Diana Iezzi
Published 24 July 2026 • 6 minute read
If you’re planning a renovation or new home, you’ve probably spent some time thinking about energy efficiency.
- Insulation
- Double glazing
- Solar panels
- Heat pumps
These measures are important because they reduce the energy required to operate a building over time.
But there is another part of the sustainability story that often receives less attention: embodied carbon.
While the term may sound technical, the concept is relatively straightforward.
What Is Embodied Carbon?
Embodied carbon refers to the greenhouse gas emissions associated with the materials and construction of a building.
This includes:
- Extracting raw materials
- Manufacturing products
- Transporting materials
- Construction and installation
- Maintenance and replacement over time
- End-of-life demolition and disposal
Unlike operational carbon, which occurs throughout the life of a building, much of embodied carbon is released before the building is occupied.
In other words, a significant proportion of a building’s environmental impact may already have occurred before anyone moves in.
Understanding embodied carbon doesn’t mean becoming an expert in building materials. It simply provides another way to make more informed decisions about our homes.
Operational Carbon vs Embodied Carbon
As our understanding of sustainable building has evolved, much of the attention has focused on operational energy.
This made sense because older buildings often required large amounts of energy for heating and cooling.
However, as buildings become more energy efficient and electricity grids become cleaner, embodied carbon represents a larger proportion of a building’s overall environmental impact.
This means that both operational carbon and embodied carbon matter.
A well-designed home should aim to reduce both.
Every Building Material Has a Story
One idea I found particularly useful while learning about embodied carbon is that most building materials come from one of three places.
They are either:
- Drilled
- Mined
- Grown
Drilled materials include petrochemical-based products such as plastics and some insulation products.
Mined materials include concrete, steel, bricks, glass and aggregates.
Grown materials include timber, bamboo, hemp and other bio-based products.
This is a simplification, but it provides a useful way of thinking about where materials come from and the resources required to produce them.
Every material carries environmental impacts. The goal is not necessarily to avoid one material entirely, but to make informed decisions about how and where materials are used.
Why Concrete Gets So Much Attention
Concrete is one of the most widely used construction materials in the world.
It is durable, versatile and often essential for foundations and structural elements.
However, cement production is also associated with significant carbon emissions.
For this reason, concrete frequently becomes a focus of embodied carbon discussions.
This does not mean concrete should never be used.
Rather, it encourages us to ask questions such as:
- Is this amount of concrete necessary?
- Can structural systems be simplified?
- Are lower-carbon concrete mixes available?
- Can existing structures be retained?
Often, reducing material use can have a greater impact than simply substituting one material for another.
Why Reuse Matters
One of the most effective ways to reduce embodied carbon is to retain and reuse existing materials and structures.
Existing walls, slabs, roof structures and foundations already represent a significant investment of materials, energy and carbon.
Retaining these elements can often avoid the emissions associated with demolition and reconstruction.
This is one reason retrofit is becoming an increasingly important part of sustainability conversations around the world.
Before asking what new materials are required, it can be valuable to ask:
What can we keep?
Building Less Can Be Better
Embodied carbon is not only influenced by material selection.
It is also influenced by how much we build.
The size of an extension.
The complexity of a structure.
The amount of demolition required.
The quantity of materials used.
Sometimes the most effective carbon reduction strategy is not a new material.
It is building less.
A carefully planned, well-used space may deliver greater environmental benefits than a larger space built from lower-carbon materials.
Good design is not always about adding more.
Sometimes it is about making better use of what already exists.
Progress, Not Perfection
One of the encouraging messages emerging from embodied carbon research is that meaningful improvements do not always require radical changes.
Better design decisions.
More efficient structures.
Thoughtful material selection.
Retaining existing buildings.
Reducing unnecessary demolition.
These actions can all contribute to lower-carbon outcomes.
Like many areas of sustainability, embodied carbon is an evolving field. New tools, databases and research are continually improving our understanding of material impacts.
For homeowners, architects and builders alike, the goal is not perfection.
The goal is making better-informed decisions than we did before.
Looking Ahead
Embodied carbon is likely to become an increasingly important part of the way we design, renovate and construct buildings.
While operational energy remains important, sustainability is no longer only about what happens after a building is occupied.
It is also about the resources required to create the building in the first place.
As our understanding continues to evolve, the conversation is shifting from asking:
What should we build?
to asking:
What should we build, what should we keep, and how can we make the best use of the resources already available?
Every material has a story long before it becomes part of your home.
Understanding embodied carbon won’t make every decision straightforward, but it can help you ask better questions, weigh up the options and make more informed choices about the home you’re creating.
Acknowledgement
This article draws on ideas explored in the London Energy Transformation Initiative (LETI) Climate Emergency Retrofit Guide, Mariana Moreira’s article The Relevance of Embodied Carbon in the Passive House World – 475 HQ Retrofit Case Study, and broader research into embodied carbon and retrofit practice.
