What is the 1-ton rule in BR18?
The 1-ton rule is a de minimis threshold defined in BR18 §297, paragraph 9. It establishes that machines and equipment with a self-weight under 1 ton are exempt from the A4-A5 calculation.
Specifically, this means:
- A4 (transport): Transport of equipment under 1 ton to and from the construction site does not need to be included.
- A5 (construction site): Fuel consumption for machines under 1 ton does not need to be recorded.
Examples of equipment under 1 ton that is exempt:
| Equipment | Typical weight | Exempt? |
|---|---|---|
| Hand tools (drills, angle grinders) | 2-15 kg | Yes |
| Compressor (small) | 50-200 kg | Yes |
| Plate compactor | 50-150 kg | Yes |
| Small generator | 100-500 kg | Yes |
| Mini excavator | 800-3,500 kg | Depends on model |
| Backhoe loader | 6,000-10,000 kg | No |
| Mobile crane | 12,000+ kg | No |
The rule is designed to remove the documentation burden for small equipment that in practice contributes minimally to the total A4-A5 impact.
Other exemptions from the A4-A5 calculation
Beyond the 1-ton rule, BR18 defines several exemptions that simplify data collection:
Water consumption
Water consumption on the construction site is not included in the A5 calculation. You don't need to record water meter data or calculate emissions from water use. This applies to both drinking water and process water.
Non-permanent consumables
Materials consumed during the construction process but not incorporated into the finished building are exempt. Examples:
- Sandpaper and abrasive materials
- Chemicals for cleaning and surface treatment
- Cleaning agents
- Machine lubricants
These items typically constitute an insignificant proportion of the total climate impact, and the exemption prevents unnecessary documentation burden.
Standard values and fixed rates that simplify calculation
BR18 Annex 2 (Table 10) defines several fixed rates that either must be used or can be used instead of actual data. Here is the complete overview:
| Item | Fixed rate | Mandatory? | When to use |
|---|---|---|---|
| Terminal processes (reloading, storage) | 0.02 kg CO₂e/m²/year | Yes — always | Must be added regardless of which calculation method you choose for A4 transport. |
| Surplus materials, packaging and similar | 0.02 kg CO₂e/m²/year | Yes — with standard method | Mandatory addition when using the kilo-based standard method (Table 10) for A4 transport. Covers transport of waste, packaging and surplus materials. |
| Transport of equipment (over 1 ton) | 0.02 kg CO₂e/m²/year | Can be used | Fixed rate for transport of heavy equipment (cranes, scaffolding, machines) to and from the site. Alternative to actual calculation. |
| Transport of construction waste | 0.06 kg CO₂e/m²/year | Can be used | When you don't know the actual transport distance for waste. |
| Transport of excavated soil | 0.06 kg CO₂e/m²/year | Can be used | When you don't know the actual transport distance for soil. |
Important: When using the standard method (kilo-based, Table 10) for A4 transport, you must always add both the terminal supplement (0.02) and the surplus materials supplement (0.02) — totalling +0.04 kg CO₂e/m²/year on top of the transport calculation itself. This is not optional.
The optional rates (equipment, waste, soil) can be used without further documentation. This saves time, particularly for items that make up a small part of the total A4-A5 budget anyway.
The fixed rates are designed to be conservative (i.e. slightly above average). If you have actual data showing lower emissions, you can choose to use that instead — except for terminal processes, which are always 0.02. Read more about standard values vs. measured data.
Complete overview: What you DON'T need to track
Here is the complete list of what you can simplify or skip in your A4-A5 data collection:
| Item | Exemption / simplification | Legal basis |
|---|---|---|
| Machines under 1 ton | Neither transport (A4) nor fuel (A5) | §297, para. 9 |
| Hand tools | Always under 1 ton — exempt | §297, para. 9 |
| Water consumption | Not included in A5 | BR18 Annex 2 |
| Sandpaper, chemicals, cleaning | Non-permanent consumables | BR18 Annex 2 |
| Terminal processes | Fixed rate: 0.02 kg CO₂e/m²/year (mandatory) | BR18 Annex 2, Table 10 |
| Surplus materials and packaging | Fixed rate: 0.02 kg CO₂e/m²/year (mandatory with standard method) | BR18 Annex 2, Table 10 |
| Transport of equipment (> 1 ton) | Can be replaced by fixed rate: 0.02 kg CO₂e/m²/year | BR18 Annex 2, Table 10 |
| Waste/soil transport distance | Can be replaced by fixed rate: 0.06 kg CO₂e/m²/year | BR18 Annex 2, Table 10 |
By knowing these rules, you can focus your time on the items that actually make a difference: transport of heavy materials, diesel for large machines, electricity consumption, and waste sorting. That's where the real savings are. See our practical guide to data collection.
Frequently asked questions
According to BR18 §297, paragraph 9, machines and equipment with a self-weight under 1 ton are exempt from the A4-A5 calculation. This applies to both transport of equipment (A4) and fuel consumption on site (A5). Hand tools, small compressors, and small generators don't need to be included.
No. Water consumption on the construction site is not included in the A5 calculation according to BR18 Annex 2. You don't need to record water meter data or calculate emissions from water use.
BR18 Annex 2 defines a fixed standard value of 0.06 kg CO₂e/m²/year for transport of construction waste. The same rate applies to transport of excavated soil. These can be used without further documentation of actual transport distances.
Yes. Non-permanent consumables consumed during construction but not incorporated into the finished building are exempt from the A4-A5 calculation. This includes sandpaper, chemicals, cleaning agents, and lubricants.
Terminal processes (reloading, storage between transport links) have a fixed rate of 0.02 kg CO₂e/m²/year according to BR18 Annex 2. You don't need to calculate actual emissions from terminal handling — use the fixed rate.
Surplus materials, packaging and similar have a fixed rate of 0.02 kg CO₂e/m²/year according to BR18 Annex 2, Table 10. This addition is mandatory when using the kilo-based standard method (Table 10) for A4 transport calculation.
Transport of equipment (heavy equipment over 1 ton such as cranes, scaffolding, and large machines) has a fixed rate of 0.02 kg CO₂e/m²/year according to BR18 Annex 2, Table 10. You can use this instead of calculating the actual transport of equipment.
It depends on the model. Mini excavators typically range from 800-3,500 kg self-weight. The smallest models (under 1 ton) are exempt, while most mini excavators in practice weigh over 1 ton and must therefore be included. Check the machine's specifications.
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