The Plausibility Checker compares your building LCA with similar real projects completed in One Click LCA. It flags results that look unusually high or low, so you can find and fix errors such as a missing material, a wrong unit, or a quantity entered twice before you report or submit your LCA. It replaces the previous LCA Checker, which was retired in January 2026.
The checker tailors its expected ranges to your project, based on its building type, frame type, number of floors, location, and certification scheme.
How it works
The checker sets an expected range for each check using real projects completed in One Click LCA. Only valid projects are used; test, demo, and training projects are filtered out.
To compare projects fairly across different LCA tools, the checker always calculates with the same fixed scope:
Embodied carbon, A1 to C4
A 60-year calculation period
New construction only
This calculation runs in the background through the Carbon Heroes Benchmark tool, which does not appear in your project's tool list. Because the scope is fixed, the numbers in the Plausibility Checker can differ from the results in the tool you are using. Your tool's results are still the ones you report.
Run the Plausibility Checker
Enter your building material data. Complete the design before you run the checker.
Set the gross internal floor area (IPMS/RICS). This is the only required input. Without it, no results appear.
Add project details (recommended). Building type, frame type, number of above-ground floors, and certification scheme make the expected ranges more relevant to your project. Add them when you create the project, or later with the More actions button.
Open the checker. Go to the results page of your design and open the Plausibility Checker.
What your design should include
Benchmarks are based on whole buildings, so the checker always includes checks for these parts, even if they are missing from your design:
Foundations and substructure
Structure and enclosure
Finishes and other materials
Two parts are optional. If your design does not include them, their checks are skipped:
External areas
Services
Read your results
The checker shows an overall grade for your project and a table with every check it ran.
Overall grade
The grade is based on how many checks fall within the typical range for similar projects. Each check counts toward the grade according to its color.
What the colors mean
Color | What it means | Counts in the grade as |
Green | Your result is within the typical range for similar projects (between the 5th and 95th percentile). | 1 |
Yellow | Your result is at the edge of the typical range (in the lowest or highest 10% of similar projects). | 0.5 |
Red | Your result is outside the range of all similar projects. | 0 |
Grey | Inconclusive: your result and the lower or upper limit of the range are both 0, while other projects have values above 0. | 1 |
A validated check counts as green, whatever its color. See Validate checks below.
Filter and explore checks
Filter by type: all checks are shown by default. Use the dropdown to show only carbon (GWP) checks, mass checks, or other checks, which are usually ratios.
See what a check covers: hover over a check's tooltip to see which data it uses.
See the expected range: the Benchmark values column shows your result against the range for similar projects. Hover over it to open a larger chart.
Validate checks
Not every result needs to be green. Some unusual results are intentional design choices. For example, buildings with a concrete or steel frame typically use little or no cross-laminated timber (CLT). If your project does use CLT, that check may show yellow or red even though your data is correct.
In that case, you can mark the check as validated:
In the validation column, turn on the toggle for the grey, yellow, or red check.
Click Save at the top of the page.
The overall grade is recalculated, and validated checks count the same as green checks.
Only users with Manager or Modifier rights on the project can validate checks.
Supported tools
Support | Tools |
Full checks | Most building LCA tools |
Mass-based checks only | LCA according to Bygningsreglementet (2018 and 2025); LCA for DGNB (all versions); LCA for Qualitätssiegel Nachhaltiges Gebäude (QNG); LCA for BREEAM UK IMPACT-compliant |
Not supported | Energy Carbon; RE2020 |
The tools with mass-based checks only calculate global warming potential differently from the benchmarks, so the checker uses a limited set of mass-based checks instead. Energy Carbon and RE2020 are not supported because their calculation methods differ too much.
Good to know
It flags, it does not verify. The checker shows which results to review. It does not replace third-party review or verification of your LCA.
It does not change your data. The checker compares your results with similar projects. Any corrections are yours to make.
New construction only. The benchmarks are based on new buildings, so checks may be less relevant for renovation projects.
The more project details, the better. Without building type, frame type, number of floors, and certification scheme, the expected ranges are less specific to your project.
Frequently asked questions
Why don't I see any results?
Check that the gross internal floor area (IPMS/RICS) is set for your project. It is the only required input.
Why are the numbers different from my tool's results?
The checker always uses the same scope (embodied carbon A1 to C4, 60 years, new construction) so projects in different tools can be compared. Your tool's own results are still the ones you report.
Where does the benchmark data come from?
From real projects completed in One Click LCA. The data is filtered to keep only valid projects; test, demo, and training projects are removed.
Does every check need to be green?
No. The checks show what to review. If an unusual result is intentional, a user with Manager or Modifier rights can validate it, and it then counts as green in the grade.
Does the AI change my LCA?
No. It shows expected ranges based on real projects and flags results to review. Your data stays as you entered it.
What happened to the old LCA Checker?
It was retired in January 2026 and replaced by the Plausibility Checker.
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