Which standard applies?

Of the three things every LCA needs (a bill of materials, a standard and a database), the standard is where most companies get stuck. It isn’t that the standards are secret. It’s that the right one depends on a question people rarely ask out loud: what will this result be used for, and who will read it?

Get that answer first and the choice usually makes itself. This lesson turns it into a short decision guide, using everything from the previous five lessons.

Start with two questions

1. Is there a legal obligation? If a regulation sets the method, you don’t choose. CBAM and the CPR both work this way.
2. Who will read the result, and what will they do with it? Your own design team, a customer’s sustainability team, an architect comparing products, the public. The wider and less friendly the audience, the stricter the rules and the more checking you need.

In costing, you’d never use the same cost model for an internal make-or-buy decision and a public price list without thinking about it. The same goes here.

Explainer

Every LCA needs three things

1. Scene 1 of 6

   Three ingredients

   A bill of materials, a standard and a database.

   Three boxes on the board: 1, the bill of materials; 2, a standard; 3, a database. Every life cycle assessment needs all three.

2. Scene 2 of 6

   1. The bill of materials

   What goes into the product, how much, and how it is made.

   The same list you use for costing.

   • You probably have it already

   The first ingredient is the bill of materials: what goes into the product, how much, and how it is made. Most companies already have it for costing and production.

3. Scene 3 of 6

   2. A standard

   The rulebook: what to include, how to allocate, how to report.

   ISO 14044·ISO 14067·EN 15804·a PCR

   The right one depends on what the result is for.

   This is where most people get stuck. Verdatir helps you choose.

   The second ingredient is a standard, the rulebook the analysis follows, such as ISO 14044, ISO 14067, EN 15804 or a product category rule (PCR). The right one depends on what the result will be used for. This is where most people get stuck, and Verdatir helps companies choose.

4. Scene 4 of 6

   3. A database

   Emission factors for materials, energy, transport and waste.

   The “price list” for carbon.

   Licensed databases cost money. Good free ones exist.

   The third ingredient is a database of emission factors for materials, energy, transport and waste: the price list for environmental cost. Licensed databases are costly, but good free ones exist.

5. Scene 5 of 6

   Before LLMs

   BOM+Standard+Database+LCA software+Specialist

   Software brought the three together, and someone trained had to drive it.

   Before large language models, you also needed dedicated LCA software and a specialist trained to drive it. They were what brought the three ingredients together, and a large part of the cost.

6. Scene 6 of 6

   Now

   BOM+Standard+Database+AI assistant + learnLCA skills

   In Claude, Claude Cowork or ChatGPT.

   No programming. No Python.

   You still need to understand the method. That is why the school comes first.

   Now an AI assistant with learnLCA skills, installed in Claude, Claude Cowork or ChatGPT, can bring the three ingredients together, with no programming. You still need to understand the method to name the right standard and check the result, which is why the school comes first.

The decision guide

What the result is for	Who reads it	Standard or method	Checking
Internal hotspot or eco-design	Your own team	ISO 14040 and ISO 14044, as a screening LCA; ISO 14067 if climate only	Internal review is usually enough
Customer PCF request	A customer’s sustainability or purchasing team	ISO 14067:2018 or the GHG Protocol Product Standard, plus any sector rules or the customer’s own guidance (for example PACT)	Whatever the customer asks for; verification adds weight
EPD for a construction product	Architects, engineers, contractors, building rules	ISO 14025, EN 15804+A2 and the complementary PCR of a programme operator	Independent third-party verification, required
CPR declaration of performance and conformity	Market surveillance, buyers, public procurement	Regulation (EU) 2024/3110, the harmonised technical specification for your product family and the Commission’s calculation method	As set for your product family
CBAM declaration	National competent authorities	Regulation (EU) 2023/956 and its implementing acts (not an LCA)	Accredited CBAM verifier for actual emissions
Public claim that your product is better than a competitor’s	The public, competitors, regulators	ISO 14044 comparative assertion disclosed to the public	Critical review by a panel of interested parties (ISO 14044; ISO 14071 for the review process)

Some notes on reading the table:

• One model, several outputs. A well-built LCA model of your product, with good data, can feed a screening study, a PCF and an EPD. The standards differ in their rules, not in the basic method. Building the model once and documenting it well is the efficient path.
• The strictest reader wins. If the same figure will go into an internal report and a tender, build it to the tender’s rules.
• When a customer or programme names a rule, use it. Many customers, sectors and programmes publish their own requirements on top of the general standards.

The traps

Common mistakes

• Using an EPD figure for CBAM, or a CBAM figure as a PCF. Different boundaries, different gases, different verification. See lesson 4.
• Comparing EPDs to different versions of EN 15804. See lesson 2.
• Making a public comparison from a screening study. Without a panel critical review, a public “ours is greener than theirs” claim doesn’t meet ISO 14044, and it may expose you to legal risk.
• Assuming the CPR requires a GWP on every product today. It applies family by family. See lesson 3.

Exercise

Which standard or method applies in each case, and what checking is needed?

1. The product manager wants to know whether switching from virgin to recycled plastic in a housing is worth it, before deciding.
2. A car maker asks your purchasing team for the cradle-to-gate carbon footprint of the aluminium brackets you supply them.
3. Marketing wants to print “40% lower carbon than the leading competitor” on the packaging.
4. An architect asks for an EPD for your façade panel for a building in Germany.
5. Your company imports 2,000 tonnes of steel coil a year from outside the EU.

Answer

1. Screening LCA to ISO 14040/14044, probably climate change plus a few other indicators to avoid shifting burdens. Internal review. No verification needed, but document assumptions so the result can be reused.
2. ISO 14067 or the GHG Protocol Product Standard, cradle-to-gate, with any rules the car maker specifies (automotive customers often have their own guidance, and may ask for PACT-format data). Ask whether they need third-party verification.
3. ISO 14044 comparative assertion disclosed to the public, with a panel critical review, and the comparison must be on the same function. In practice, most companies decide the claim isn’t worth it, or get legal advice first.
4. An EPD to ISO 14025 and EN 15804+A2, with the relevant complementary PCR, from a programme operator the architect’s project accepts, with independent verification.
5. CBAM: you are well above the 50-tonne threshold. You need to be an authorised CBAM declarant, and to collect installation-level embedded emissions from your suppliers, calculated with the CBAM methodology and verified by an accredited verifier (or pay on default values). This is not an LCA choice at all.

Getting help for a specific product

The guide above covers the common cases. Real products often sit between them: a product sold both to construction and to industry, a customer with its own rulebook, or a regulation whose product-family rules are still being written. Verdatir, the company behind learnLCA, helps companies work out which standard applies to a specific product and what the result will need to survive.

What you should now be able to do

• Ask the two questions that decide the standard: is there a legal obligation, and who will read the result?
• Match six common uses to the right standard or method and level of checking.
• Explain why one well-documented LCA model can feed several outputs.
• Spot the common traps, such as using an EPD figure for CBAM.

Sources

• ISO 14044:2006, comparative assertions and critical review, iso.org.
• ISO 14071:2024, critical review processes and reviewer competencies, iso.org.
• ISO 14067:2018, iso.org; ISO 14025:2006, iso.org.
• GHG Protocol, Product Standard.
• Regulation (EU) 2024/3110 (CPR), EUR-Lex.
• Regulation (EU) 2023/956 (CBAM), EUR-Lex, as amended by Regulation (EU) 2025/2083, EUR-Lex.

Checked: 2026-09-29