The LCAbyg project file (.lcabyg.json): what the file contains
.lcabyg.json is LCAbyg’s own, publicly documented project format. A single file can contain a
whole project (all versions) or a single version, with or without calculation results. The format
is built so the customer can read the file themselves without help from LCAbyg, and so an
export-import-export cycle produces a file with identical content again.
What the file contains
Section titled “What the file contains”- The project’s metadata: name, description, address, client, LCA consultant, project type.
- Each version, with settings, areas, the building model’s constructions and building products, all consumption lines (energy, transport, waste and more), transport methods and any special conditions.
- Optional: calculation results. Results are derived data. They are never imported back, an imported file is always recalculated instead, and the results in the file are only for archiving and sharing.
- Optional: an overview of the library content the project builds on (name, unit, emission data and more), to document the data basis. This is not the same as a library import, the content is not written into any library on import.
Two kinds of GUIDs
Section titled “Two kinds of GUIDs”Every construction and building product has two different identities in the file. One is its library identity (the same GUID can recur in several places if the same library item is used more than once). The other is its instance identity in this particular building model, which is unique and stays the same across export and import. It is the instance identity that makes it possible to recognise the same building product again, for example in an external quantity take-off sheet.
Versioning of the format itself
Section titled “Versioning of the format itself”The file carries its own format version number (major.minor). A file with a different major version than the one LCAbyg supports is rejected on import. A newer minor version is imported with a warning about the fields LCAbyg does not yet know. An older minor version is imported without warning, because minor changes are always additions, never removals.