The GHG Protocol Corporate Standard splits an organisation's emissions into three scopes, so that each tonne is counted once and by the right party. For a contractor, drawing the line is mostly a question of who controls the activity.
Scope 1: direct emissions
Sources the company owns or controls.
| Source | Typical data | Factor (DEFRA 2026) |
|---|---|---|
| Diesel in plant and vehicles | fuel receipts, bulk deliveries (litres) | 2.58354 kg CO₂e per litre (average biofuel blend) |
| Gas oil in generators | delivery notes (litres) | per litre, gas oil |
| HVO | fuel receipts (litres) | 0.03558 kg CO₂e per litre, biogenic CO₂ reported separately |
| Natural gas in offices and depots | gas bills (kWh) | 0.18231 kg CO₂e per kWh (gross CV) |
| Refrigerant leaks | service records (kg topped up) | the gas's global warming potential |
Fuel is often the largest Scope 1 line. Idle time is a large, avoidable part of it: see idling plant.
Scope 2: purchased energy
Electricity, heat, steam and cooling that the company buys and uses. That includes temporary builders' supplies on site and permanent supplies at offices and yards.
Scope 2 is reported two ways. Location-based uses the grid average: 0.13096 kg CO₂e per kWh in the 2026 UK factors. Market-based reflects your contracts, such as REGO-backed tariffs and PPAs, with a residual mix for the rest. Headline totals normally use one method and show the other beside it. See location-based and market-based Scope 2 and what changed in the 2026 factors.
Scope 3: the value chain
Everything else the company causes but does not control. For contractors the material categories are usually:
- Category 1, purchased goods and services: concrete, steel, aggregates, asphalt, timber, and subcontracted labour and services. Often the largest part of the footprint. Supplier or quantity data is best; spend-based factors are the fallback. See spend-based Scope 3 with factors you can source.
- Category 2, capital goods: plant and vehicles bought.
- Category 4, upstream transportation: deliveries to site you pay for.
- Category 5, waste generated in operations: skips and muck-away, from waste transfer notes and weighbridge tickets. See from a waste ticket to a reported tonne.
- Categories 6 and 7, business travel and employee commuting.
The embodied carbon of materials installed on a project is also tracked project by project under PAS 2080: see embodied carbon and data quality.
Drawing the boundary
- Choose a consolidation approach, usually operational control, and apply it to joint ventures and subsidiaries.
- Decide how hired plant is treated. Fuel you buy for hired plant is usually your Scope 1. Fuel a subcontractor buys is your Scope 3.
- Write it down. The boundary statement is the first thing a verifier reads.
Which scopes are required
| Framework | Scopes |
|---|---|
| SECR | Scope 1 and 2 from UK energy use, see our SECR guide |
| PPN 006 Carbon Reduction Plan | Scope 1, 2 and Scope 3 categories 4, 5, 6, 7, 9, see our PPN 006 guide |
| SBTi near-term targets | Scope 1 and 2, plus Scope 3 when it is 40% or more of the total |
MetricOra records all three scopes, including all 15 Scope 3 categories. It calculates each record with a named factor and stores the formula. See the platform.
Frequently asked questions
What is Scope 1 for a contractor? Fuel burnt in plant, generators and vehicles you control, gas in your buildings, and refrigerant leaks.
What is Scope 2? Purchased electricity, heat and cooling, reported location-based and market-based.
What is Scope 3? The rest of the value chain: materials, subcontractors, waste, transport, travel and commuting.
Is hired plant Scope 1 or 3? It depends on who controls the fuel; state your rule.