Revision clouds and deltas for permit resubmittals
Reviewers approve what they can see changed. Revision clouds and delta tags are how you show them. Here's how to draw and number them, and the rule that differs most between departments: whether last round's clouds stay on the sheets.
What clouds, deltas and the revision block are
- A revision cloud is a scalloped outline drawn around the part of a sheet that changed.
- A delta is a small triangle with the revision number in it, placed next to the cloud.
- The revision block is a table in the title block of each sheet listing every revision: its number, date and a short description.
Together they let a reviewer flip through a resubmitted set, find every change, and tie it to a submittal date, without comparing the old and new sheets line by line.
How to cloud a resubmittal
- Cloud every change, including small ones like a new note or a corrected dimension. Draw the cloud tightly around the change, not around the whole sheet.
- Put a delta next to each cloud with this submittal's revision number.
- Add a line to the revision block on every sheet that changed: the delta number, the date, and a description such as "Plan check corrections, round 1."
- Number revisions in order. The first resubmittal is usually 1, the next one 2, and so on.
- Point to the clouds in your response letter. For each comment, give the sheet and detail where the reviewer will find the clouded change. Our response letter template has room for this.
Old clouds: remove them or keep them?
This is the part that varies most. The City of Milpitas shows both approaches in one handout, depending on what you're submitting:
| What you're resubmitting | What Milpitas asks for |
|---|---|
| A new permit application that's still in plan check | Cloud this round's changes with a delta for this resubmittal, and turn off the clouds from earlier submittals. Resubmit the complete drawing set. |
| A revision to a permit that's already issued | Keep all clouds and deltas from the first revision submittal and every resubmittal on the drawings, and cloud new changes with the revision's own delta number. Only clouded, numbered changes count as part of the approved revision. |
Other departments have their own rules, and many don't write them down. If yours doesn't say, ask the reviewer or the permit counter before you resubmit. A common approach is to keep the full history in the revision block while clouding only the current round's changes on the drawings.
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Answer my correctionsChanges the reviewer didn't ask for
If you change something that wasn't in the correction letter, cloud it like any other change and call it out separately. Milpitas, for example, asks for a separate letter describing changes that aren't part of the responses to comments, with the sheet numbers. Unannounced changes can trigger new comments, or simply be missed and left out of what was approved.
Drawing clouds on a PDF
CAD programs have a revision cloud command, and PDF editors such as Adobe Acrobat and Bluebeam include cloud markup tools. Plan Check Correct also draws them for you: load your plan PDF, drag a box where each change is, and it adds the revision cloud, delta tag and note for that correction. Before uploading to an electronic plan review portal, check its instructions. Some ask for markups to be flattened into the PDF, or for one file per sheet named a certain way.
Mistakes that send a resubmittal back
- Changes with no cloud. The reviewer may not find them, or may return the set.
- One huge cloud around the whole sheet. It hides what actually changed.
- Deltas that don't match the revision block, or a revision block that wasn't updated.
- Leftover clouds from earlier rounds when the department wants them off, so already-accepted work gets reviewed again.
- A change clouded on one sheet but not on the others it affects, like a window moved on the floor plan but not on the elevation.
Frequently asked questions
What does the delta symbol mean on plans?
A delta is a small triangle with a number in it. The number is the revision the change belongs to, and it matches a line in the revision block of the title block that gives the date and a short description. A delta 1 next to a cloud means that change was made in revision 1.
Should I remove revision clouds from the previous submittal?
It depends on the department and the kind of submittal. For a permit still in plan check, many departments want only the current round's changes clouded and earlier clouds turned off. For a revision to a permit that's already issued, some want every cloud and delta from the revision kept on the drawings. Check your department's resubmittal instructions, and ask if they don't say.
Do I need to cloud changes the reviewer didn't ask for?
Yes. Cloud every change, and list the ones that weren't in response to a comment separately in your letter. Unmarked changes can be missed in review, and some departments only treat clouded, numbered changes as part of the approved revision.
Can I resubmit without clouds?
Usually not. Many departments return a resubmittal that doesn't identify its changes. The City of Malibu, for example, says it will reject a resubmittal that doesn't clearly cloud the revised areas and number them with deltas.