Every carbon framework you'll meet — SECR, PPN 06/21, PAS 2080 — is built on the same three-part split. Get Scope 1, 2 and 3 clear once and the rest gets much easier.
Where do the three scopes come from
The idea of "scopes" comes from the Greenhouse Gas (GHG) Protocol, the world's most widely used carbon accounting standard. It splits an organisation's emissions into three groups based on who controls the source, which is what makes reporting consistent and comparable.
Every UK framework a contractor meets, SECR, PPN 006/21, and PAS 2080, uses this same Scope 1/2/3 structure. Learn it once, and you've learned the backbone of all of them.
Scope 1 — emissions you burn directly
Scope 1 covers direct emissions from sources you own or control. On a construction site that's mostly combustion, you can see and smell the following:
- Red diesel and diesel in excavators, telehandlers, dumpers and generators
- Gas or oil heating in site cabins and offices
- Fuel in company-owned vans and vehicles
- Any on-site process that burns fuel
If you're burning it yourself, it's almost always Scope 1.
Scope 2 — the energy you buy
Scope 2 covers indirect emissions from purchased energy. You didn't burn it, but it was generated on your behalf:
- Grid electricity for site hoarding, tower cranes, welfare units and offices
- Purchased heat or steam (rare on most sites)
Because the power station burnt the fuel, not you, it sits in Scope 2 rather than Scope 1, but it's still your responsibility to report.
Quick test. Ask "did we burn a fuel directly?" If yes → Scope 1. "Did we buy energy someone else generated?" → Scope 2. "Is it anywhere else in our supply chain?" → Scope 3.
Scope 3 — everything else in your value chain
Scope 3 covers all other indirect emissions — upstream and downstream of your operations. For construction, this is the big one, and it usually includes:
- Embodied carbon in materials — concrete, steel, timber, insulation, plasterboard. This is typically the single largest category on a project.
- Transport and logistics — deliveries of materials and plant to site, and haulage away.
- Subcontractor activities and hired plant you don't own.
- Waste generated on site and its disposal route.
- Business travel and employee commuting.
Why Scope 3 dominates construction
Here's the point most people miss: for a typical construction project, Scope 3 is by far the largest share of the footprint, often 70–90% of total emissions, driven overwhelmingly by the embodied carbon of materials.
That has a practical consequence. A firm that reports only Scope 1 and 2, its site diesel and electricity, is measuring the small end of its impact and ignoring the part clients increasingly ask about. Specifying lower-carbon concrete or steel, or cutting delivery miles, usually moves the number far more than switching a generator.
How the scopes map to UK frameworks
| Framework | What it asks for |
|---|---|
| SECR | Scope 1 and Scope 2 in full; Scope 3 partially (at minimum, business travel in owned/leased vehicles). |
| PPN 06/21 | Scope 1, Scope 2, plus five defined Scope 3 categories (business travel, commuting, upstream & downstream transport, waste). |
| PAS 2080 | Whole-life carbon across all scopes: capital (embodied), operational and end-of-life. |
The common thread: they all start from Scope 1, 2 and 3. If your project data is already split that way, producing any of these reports becomes a formatting exercise rather than a data-gathering scramble.
How to get the split right
- Capture activity data — litres of fuel, kWh of electricity, tonnes of material, delivery distances, tonnes of waste.
- Apply the current DEFRA conversion factors to turn each into kg CO₂e.
- Assign each entry to a scope using the tests above.
- Report against a baseline so you can show reduction over time, not just a single snapshot.
The hard part is rarely the definitions; it's capturing the activity data consistently, site after site, so the numbers are ready the moment a tender or a client asks for them.