Standard values vs. measured data: When can you use BR18's table values?

BR18 does not give you free choice for all items. Some data must be measured, others must use a fixed standard value, and a third category gives you freedom to choose. Here are the rules:

Data point	Method	Rationale
Electricity, heating, fuel for machines > 1 tonne	Mandatory measured data	The building owner's actual consumption must be documented.
Terminal handling	Mandatory standard value	Fixed 0.02 kg CO₂e/m²/year — cannot be changed.
Material transport (A4)	Optional	Standard values (Table 10), measured data, or EPD.
Waste and soil transport	Optional	Standard value (0.06 kg CO₂e/m²/year) or measured data.
Construction waste (fractions)	Optional	Table 11 factors with actual weight, or EPD data.

The key point: you can freely mix methods within the same project. You can use measured data for concrete transport and standard values for insulation materials — there is no requirement for consistency across materials. For the full overview of requirements, see our BR18 A4-A5 guide.

The standard values in BR18 are deliberately conservative. They are set high as a precautionary principle — and as an incentive to collect actual data. When you use Table 10 for transport calculation, you must add two surcharges:

• +0.02 kg CO₂e/m²/year for terminal handling (this surcharge is fixed and always applies).
• +0.02 kg CO₂e/m²/year for spillage and packaging when using standard values.

The total surcharge is therefore +0.04 kg CO₂e/m²/year when you choose standard values for transport. It doesn't sound like much, but it is added on top of every single material, and it adds up.

Standard values generally yield a higher result than actual data, simply because they are designed as worst-case. That is the price of convenience.

Let's look at a concrete example: transport of plasterboard over 200 km to a building with a reference area of 300 m².

Method	Calculation	Result
Standard value (Table 10)	Table value for truck 200 km + terminal surcharge 0.02 + spillage/packaging 0.02	~0.041 kg CO₂e/m²/year
Measured data	Actual fuel consumption per delivery, actual weight, actual distance	~0.00057 kg CO₂e/m²/year
EPD data	Manufacturer's environmental product declaration with A4 module	Varies — typically between standard value and measured data

In this example, the standard value is approximately 70 times higher than the measured data. This is not an error — standard values are dimensioned to cover the worst-case scenario. If you use them for all materials, you will quickly fill the budget.

Environmental Product Declarations (EPDs) according to EN 15804 can be used as an alternative data source for A4. They provide product-specific emission data, often lower than standard values but higher than actual measured data.

The pitfalls of EPDs:

• Validity: An EPD is valid for 5 years. Use an expired EPD and your calculation may be rejected during spot checks.
• Unit conversion: EPDs state data per declared unit (e.g., per m², per kg, per piece). Conversion errors between the EPD unit and your actual quantity are a frequent source of mistakes.
• Distance assumptions: The EPD's A4 module is typically based on an assumed transport distance. If your actual distance is shorter, measured data may yield a lower result.
• Coverage: Not all products have an EPD. In practice, you have EPDs for standard products (concrete, steel, insulation) but rarely for specialty products.

The most effective approach is a pragmatic mix of methods. Here is a recommendation based on the best balance between effort and result:

Item	Recommended method	Rationale
Concrete, steel, large material volumes	Measured data	Large CO₂ item — actual data typically yields significantly lower results.
Energy consumption (electricity, heating, diesel)	Measured data (mandatory)	Required by BR18. Read meters continuously.
Smaller materials, specialty products	Standard values / EPD	Low CO₂ share — the effort of measuring does not outweigh the savings.
Waste fractions	Weigh slips + Table 11	Weigh slips from receiving facilities provide actual weight per fraction.
Waste/soil hauling	Standard value (0.06 + 0.06)	Standard value typically covers the need — the savings from measured data rarely justify the effort for this item.

The key is to focus your data collection effort where it has the greatest impact. A45 lets you compare all three methods per emission and automatically select the lowest — and still correct — result. See also our comparison of A45, LCAbyg, and Excel.