Wondering what sustainable building really means for you? In short, it means designing, building and running homes and other buildings so they use less energy, carbon and material across their whole life.
| Key fact | Value |
|---|---|
| Buildings and construction share of global emissions | 37 per cent |
| Buildings and construction share of global material extraction | Nearly 50 per cent |
| Embodied emissions from cement, steel and aluminium | Around 2.1 GtCO₂ per year |
| Sector pathway to full decarbonisation by 2050 | Not on the required trajectory |
| Edition of the UNEP and GlobalABC status report | 10th edition, 2025/2026 |
These figures come from the Zenodo record and the BUILD UP summary of the Global Status Report for Buildings and Construction 2025-2026. Figures can change with each edition, so check the source before you rely on them.
What does sustainable building actually mean?
Sustainable building looks at a building’s whole life: the materials that go into it, the way it is constructed, how much energy it needs every day, and what happens when it is repaired, changed or taken apart. A simple test is whether the building leaves people and the planet better off than a typical alternative would.
The topic usually covers these areas:
- Energy used for heating, cooling, lighting and cooking.
- Materials and the carbon locked into them.
- Comfort, health and safety for the people inside.
- Resilience to a changing climate.
- Affordability, so that better buildings are within reach.
If you prefer the design-led view, the guide to sustainable architecture looks at the same goals from the architect’s side of the table.
Why buildings matter so much for the climate
The UNEP and GlobalABC status report says the sector accounts for 37 per cent of global emissions and nearly 50 per cent of global material extraction, as of its May 2026 publication. It is a measure of how much of the world’s climate and resource pressure sits in the places where people live and work.
The same report, titled “Building fast. Falling short”, says the sector remains off track. The BUILD UP summary adds that the Global Buildings Climate Tracker shows the sector is not on the trajectory required for full decarbonisation by 2050.
There is some good news in the same summary. Efficiency improvements and cleaner power have slowed the growth of emissions, although overall progress remains insufficient, according to BUILD UP.
Operational and embodied carbon: two sides of one problem
Operational emissions come from running a building. The status report notes that operational emissions increased between 2015 and 2024, and that fossil fuels continue to dominate heating, cooling and cooking in many regions, according to the BUILD UP summary.
Embodied emissions are the ones released before anyone moves in, through making materials and putting them together. Embodied emissions from cement, steel and aluminium remain stable at around 2.1 GtCO₂ per year, per the same summary. The guide to embodied carbon in buildings explains how to think about this hidden share.
Looking at only one side can shift the problem rather than solve it. A very efficient new building still carries embodied carbon, while an old building that runs on fossil fuels keeps adding operational emissions. That is one reason the same summary stresses the need to retrofit existing buildings.
Common ways to cut both kinds of carbon include:
- Reusing or retrofitting an existing building before building new.
- Choosing lower-carbon materials and using less of them.
- Designing the building so it needs less energy to stay comfortable.
- Moving heating and cooking away from fossil fuels.
Materials: what to look for beyond the label
No material is sustainable on its own. What counts is where it comes from, how much energy goes into making and moving it, how long it lasts, and whether it can be repaired or reused. A material is only as good as the way it is used.
Plant-based options are a common starting point, and the guide to bamboo construction shows how builders work with it. To weigh up the evidence, read the answer to the question is bamboo a sustainable building material.
Earth is another traditional option that designers are revisiting. The overview of rammed earth construction explains how these walls are made and where they suit a project.
You can also look at reclaimed and reprocessed products. The guide to recycled building materials shows where they can replace new, resource-heavy ones.
Whatever the material, put these questions to the supplier or designer:
- Where does it come from, and how far has it travelled?
- How much energy and carbon went into making it?
- How long will it last, and what maintenance does it need?
- Can it be repaired, reused or recycled at the end of its life?
Design strategies that cut energy use
The cheapest energy is the energy a building never needs. Passive design starts with the shape, orientation, insulation and airtightness of the building, and only then adds machines to fill the gaps. The guide to passive house design describes one well-known approach.
Fresh air does not always need a fan or a compressor. The explainer on natural ventilation in buildings shows how layout and openings can keep rooms comfortable.
Planted roofs add another layer. The guide to green roof benefits covers what they can offer a building and its surroundings.
The status report also points to the policy side. It says policies to phase out fossil fuels for heating, cooling and cooking are still limited, which makes building-level choices more valuable, according to BUILD UP.
How can you tell whether a sustainability claim is credible?
Labels such as “green” or “eco” are easy to print and hard to check. The Global Buildings Climate Tracker benchmarks progress across emissions, building energy codes, renewable energy, green building certification and investment in energy efficiency, per the Zenodo record. Those are good prompts for your own questions.
Use these steps when you read a claim:
- Ask whether it covers the whole life of the building or only energy use.
- Look for measured performance, not only design intent.
- Check what a certification actually covers and who awarded it.
- Ask whether an existing building could be improved instead of replaced.
- Look for plans that deal with heat, storms or flooding as well as emissions.
The same questions help when you choose where to stay on a trip, and the guide to sustainable travel shows how they apply there.
Frequently asked questions
What is sustainable building in one sentence?
Show answer
It is the practice of designing, constructing and running buildings so they use fewer resources and cause less climate harm across their whole life.
How much of global emissions come from buildings?
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The UNEP and GlobalABC status report puts the buildings and construction sector at 37 per cent of global emissions, as of its May 2026 publication. Check the source for newer editions.
Is a new green building always better than keeping an old one?
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Not automatically. A new building adds embodied carbon, so it is worth comparing it with a retrofit, and the BUILD UP summary highlights the need to retrofit existing buildings.
Does one material make a building sustainable?
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No. Sourcing, durability, energy use and end of life all matter, so judge the whole building rather than a single product.
