What to collect for A4 — transport to the construction site
Module A4 covers transport of materials and heavy equipment from supplier to construction site. Which data you need to collect depends on which calculation method you choose:
| Calculation method | Required data | Source |
|---|---|---|
| Kilo-based standard (Table 10) | Material weight (kg) | Delivery note, invoice |
| Distance-based (Table 10) | Material weight (kg), transport distance (km), transport mode | Delivery note, Google Maps, carrier agreement |
| Fuel-based (Table 8.2) | Fuel type and amount (litres/kg) | Carrier, invoice, fuel receipt |
| EPD data (EN 15804) | EPD with A4 module, actual transport distance, quantity in declared unit | Manufacturer, EPD database |
You can freely mix methods within the same project — e.g. fuel-based for concrete transport and standard values for smaller materials.
What to collect for A5 — construction site activities
Module A5 is typically the most data-intensive. Here is a complete overview of what must be documented:
Energy consumption
| Item | Data source | Frequency |
|---|---|---|
| Electricity (kWh) | Site electricity meter | Monthly reading |
| District heating (kWh/MWh) | Heating bill, meter data | Monthly/quarterly |
| Diesel for machinery (liters) | Fuel receipts, tank invoices | Ongoing |
| Petrol for machinery (liters) | Fuel receipts | Ongoing |
| Gas/propane (kg or liters) | Gas supplier invoice | Upon delivery |
Construction waste
| Item | Data source | Note |
|---|---|---|
| Waste quantity per fraction (tons) | Weighing slip from receiving facility | BR18 defines 15 fractions |
| Transport distance for waste (km) | Agreement with waste handler | Or use standard value 0.06 kg CO₂e/m²/year |
Soil
| Item | Data source | Note |
|---|---|---|
| Soil quantity (tonnes) | Weighing slip | Only soil classified as waste by the Environmental Protection Agency. Soil is not in Table 11 (waste fractions) — only as a transport item with fixed rate 0.06 kg CO₂e/m²/year. |
| Transport distance for soil (km) | Agreement with hauler | Or use standard value 0.06 kg CO₂e/m²/year |
Who collects what — and when?
Data collection for A4-A5 involves multiple parties. Here is a role distribution that works in practice:
| Data | Responsible party | When |
|---|---|---|
| Delivery notes (material deliveries) | Main contractor / trade contractor | At each delivery |
| Fuel receipts (machinery) | Contractor with machines on site | At each refueling |
| Electricity meter reading | Main contractor / site manager | Monthly |
| Heating bill | Main contractor / site manager | Monthly/quarterly |
| Weighing slips (waste) | Waste handler / main contractor | At each collection |
| Subcontractor data | Each subcontractor | Monthly (agree in contract) |
The most important principle: Data must be collected continuously during construction — not reconstructed retrospectively at project completion. If data is missing at the end, you're forced to use standard values, which are typically 2-3 times higher than actual figures.
Subcontractors are obligated to deliver their data if agreed in the contract. Ensure you specify this in the tender documents — read more about responsibility allocation in contracts.
Exemptions and simplifications: What you DON'T need to collect
BR18 contains several simplifications that reduce the documentation burden. Know them — they save time:
- 1-ton rule (§297, para. 9): Machines and equipment under 1 ton are exempt from A5 energy tracking. Transport of equipment under 1 ton is exempt from A4. This means: hand tools, small generators, hand-carried machines don't need to be included.
- Water consumption: Water is not included in the A5 calculation. You don't need to record water meter data.
- Non-permanent consumables: Sandpaper, chemicals, cleaning agents, and similar consumable materials not incorporated into the finished building are exempt.
- Standard value for waste transport: Instead of calculating actual transport emissions for construction waste, you can use the flat standard value of 0.06 kg CO₂e/m²/year.
- Standard value for soil transport: Similarly, you can use 0.06 kg CO₂e/m²/year for transport of excavated soil.
- Terminal processes: Fixed rate of 0.02 kg CO₂e/m²/year for terminal handling.
- Spillage and packaging: Fixed rate of 0.02 kg CO₂e/m²/year for material spillage and packaging.
Practical checklist: Data collection from day one
Use this checklist to ensure your data collection is in order from construction start:
Before construction
- Define data requirements in all contracts (who delivers what, when, in what format)
- Set up project in calculation tool
- Designate a data-responsible person on the construction site
- Agree on reporting frequency with subcontractors (recommended: monthly)
- Ensure separate electricity meter on the construction site
During construction
- Save all delivery notes and invoices from material deliveries (A4)
- Record fuel receipts for all machines over 1 ton (A5)
- Read electricity meter at least once a month (A5)
- Save weighing slips for all waste — sorted by fraction (A5)
- Upload data continuously — avoid accumulation
- Check the running CO₂ status at least quarterly
At project completion
- Collect remaining data from all subcontractors
- Perform final "as-built" calculation with actual data
- Generate BR18-compliant report
- Archive all documentation (minimum 5 years)
How to handle data from subcontractors
Subcontractors are one of the biggest challenges in A4-A5 data collection. They have their own machines, own materials, and own suppliers — but their emissions count toward your project.
What the subcontractor must deliver
- Fuel consumption for machines on site (diesel/petrol, liters per month)
- Delivery notes for their own material deliveries (weight, distance, transport mode)
- Weighing slips for their own waste, if disposed of separately
How to ensure delivery
- Specify data requirements in the contract — preferably with a reporting template
- Agree on monthly frequency and a fixed contact person at the subcontractor
- Consider penalties (daily fines or withholding partial payment) for non-delivery
- Offer access to a shared digital tool so the subcontractor can upload directly
A45 gives all project participants access to upload invoices and delivery notes directly in the project — so data doesn't disappear in email chains between parties. For a complete overview, see our BR18 A4-A5 guide.
Frequently asked questions
For A4 (transport), you must document material weight (tons), transport distance (km), transport mode, fuel type, and optionally actual fuel consumption for each delivery. Sources are primarily delivery notes and invoices from material suppliers.
For A5 (construction site), you must document electricity consumption (kWh), heating consumption, fuel for machines over 1 ton, construction waste sorted into 15 fractions (weighing slips), and optionally soil transport. Sources are electricity meters, fuel receipts, heating bills, and weighing slips.
Data must be collected continuously throughout construction. Waiting until project completion means missing data, forcing you to use conservative standard values. These are typically 2-3 times higher than actual figures and can mean the difference between compliance and exceeding the limit.
Yes, subcontractors must deliver data for their own materials, machines, and waste if agreed in the contract. Specify data requirements in the tender documents and agree on monthly reporting. Without the subcontractor's data, you're missing a significant part of the overall picture.
Machines and equipment under 1 ton (the 1-ton rule), water consumption, and non-permanent consumables (sandpaper, chemicals) are exempt. Additionally, you can use flat standard values of 0.06 kg CO₂e/m²/year for waste and soil transport, plus 0.02 for terminals and spillage.
The most important tables in BR18 Annex 2 are: Table 8.1/8.2 (energy and fuel factors), Table 10 (transport emissions per ton-km), and Table 11 (emission factors for 15 waste fractions). These are used to convert your raw data into CO₂e.
At least once a month. More frequent readings provide better insight into consumption patterns and make it easier to identify unexplained increases — e.g. from disproportionate construction drying or unauthorized use.
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