A revision is a named save point of the whole project, kept until an admin deletes it — Initial Design, Detailed Design, Planning submission.
The project is always on exactly one revision, the current one, and everything you do is saved to it. The project never drifts away from the revision it is on.
Find them under History → Revisions.
Create a revision
Save current state as revision captures the project as it stands right now.
You can also promote an older point: open the â‹® menu on any entry in the history log and choose Save as revision.
Name it after the milestone it represents rather than the date — the date is recorded anyway.
Reading the list
Each revision shows who saved it, when, and the project’s emission figure at that point. Where a figure has moved, the change from the previous revision is shown beside it — 0.13 kgCO₂-eq/m²/year, −0.1 — so the effect of a design stage is visible without opening anything.
Preview or continue
The two actions on a revision are different, and the difference matters:
Switching back and forth is safe. Each revision keeps the work done while it was current, so continuing from another one neither creates a save point nor loses one.
Continue from this is not the same as restoring a version. Continuing moves this project onto a revision it already holds. Restoring rebuilds materials and project data from the event store at a pinned point into a new project, leaving this one untouched. Switch from anywhere
You do not have to come back to this tab. The revision name in the breadcrumb is a switcher, available on every page of the project.
Picking another revision previews it, and a banner makes clear you are looking rather than working — Back to current returns you. Manage revisions opens this tab.
Rename and delete
Renaming and deleting are admin actions. Renaming changes only the name — nothing about the saved state. The revision the project is currently on cannot be deleted.
Why they matter for reporting
Exported reports are pinned to a revision. A report names the revision and version it was taken from, and is listed while the project is on — or previewing — that revision.
That is what makes a delivered number reproducible: months later you can preview the revision a report was issued from and see exactly the figures behind it, even though the live project has moved on.
Save a revision at every milestone you report on — a planning submission, a design freeze, a client issue. It costs nothing, and the emission delta between revisions then tells the story of the project on its own.
Comparing design stages
Because each revision is a complete state of the project, previewing two in turn is the simplest way to see what changed between design stages — the dashboard totals, the mapping progress, and the charts all follow.
For comparing variants side by side rather than in sequence, clone the project instead and change one thing in the copy. 
