A plan with no notes leaves the reader guessing. A plan with too many hides the building under its own commentary. The method below works the same on tracing paper, in CAD or in a browser editor, because the problems are about reading, not about software.
1. Decide who will read it
The same plan needs different notes for different readers, and most clutter comes from writing for all of them at once. Name the reader first. If there are two, make two copies rather than one crowded sheet.
| Reader | What they need | What usually serves them |
|---|---|---|
| Client or family | What changes, and where | Room names, highlights, a few plain notes |
| Builder | What to do, and what to check on site | Callouts tied to objects, keyed notes, dimensions |
| Authority or reviewer | What the rules ask to see | What their submission list asks for, and nothing that confuses it |
| Visitor or tenant | Where they are and where to go | "You are here", a route, a few large labels |
2. Keep notes apart from the drawing
Before adding anything, decide which words belong to the building and which are comments on it. A room name, a dimension or a door tag describes the building and stays on every copy. "Check this on site" or "option for the client" is a comment for one occasion, and it should come off without touching the drawing.
On paper that meant an overlay sheet. In CAD it means a separate layer. Whatever the tool, the test is the same: can you produce the clean plan in one step, without deleting anything?
3. Choose the simplest mark for each message
Use the plainest mark that does the job, in this order: put the words beside the thing, then add a leader, then key it with a number. A symbol or a colour saves space only if the reader already knows it or a legend says what it means.
| Mark | Says | Use it when |
|---|---|---|
| Room name and area | What a space is and how big | Part of the drawing. Keep it on every copy. |
| Short note | A fact about the place it sits in | Beside the thing, with no leader, when nothing else is close. |
| Callout | A fact about one specific object | When the note cannot sit next to it, or the area is crowded. |
| Numbered marker | Several notes on one sheet | A number on the plan and the words in a list beside it. |
| Arrow | A direction or a way in | One movement, such as the front door or a fall in level. |
| Route | A journey through the building | A path with turns, drawn so it stays readable over the plan. |
| Highlight | An area under discussion | The extent of work, a phase, a room being changed. |
| Symbol | A repeated, recognisable item | When the same thing occurs in several places. |
| Legend | What the symbols and lines mean | As soon as a reader might have to guess. |
4. Size text for the printed sheet
A note has two sizes: its height on the plan and its height on paper. Only the second one is read. Multiply the height you want on paper by the scale to find the height to draw.
| Height on paper | At 1:50 | At 1:100 | At 1:200 |
|---|---|---|---|
| 2.5 mm | 125 mm | 250 mm | 500 mm |
| 3.5 mm | 175 mm | 350 mm | 700 mm |
| 5 mm | 250 mm | 500 mm | 1000 mm |
Around 2.5 mm on paper is a common smallest size for notes. Use larger text for headings, and for anything read at a distance, such as a plan on a wall. Keep to two or three sizes on a sheet. If you change the scale, check the notes again: a note drawn for 1:100 is half as tall on paper at 1:200.
5. Keep leaders short and uncrossed
A leader is there to connect, and every extra centimetre is more linework to read through. Put the note in clear space close to the object. Do not let a leader cross another leader or a dimension line, and stop it at the edge of the words. Line the notes up where you can, because a tidy column reads as one list.
6. Key the notes when there are many
Once a sheet holds more than a handful of notes, the words start competing with the walls. Put a number on the plan and the sentence in a list beside it. The plan stays readable and the list can run as long as it needs. Each number should mean one thing, and any note repeated across the sheet should keep the same number.
7. Add a legend that matches the sheet
A legend answers one question: what does this mark mean? List every symbol, line style and colour that a reader could misread. Leave out anything that is not on this sheet, because a row with nothing to match sends the reader looking for something that is not there. Check the legend again after every round of changes, since one drawn by hand goes out of date without warning.
8. Never rely on colour alone
Plans get printed in black and white, copied and read by people who see colour differently. If two routes differ only by colour, a greyscale copy shows one route. Make them differ in pattern too: solid and dashed, say. Keep fills translucent so walls show through, and draw highlights beneath the linework. Print one test copy in greyscale before you send anything.
9. Treat safety marks as a draft
Exits, routes and assembly points are useful to mark while you think about a building, and a simple plan can help a household or a small team. An official evacuation plan is a different document. What it must show, and which signs it must use, depends on the country and the type of building. Have it checked against your local rules by the person responsible for fire safety there, whichever tool you used to draw it.
10. Check it the way it will be read
- Print it at its real size, or view the PDF at 100 %, and read every note at arm's length.
- Cover the words. The building should still read clearly from the linework alone.
- Follow every leader from the note to its object. It should land on the thing it names.
- Compare the legend with the sheet, in both directions.
- Print it in greyscale and see whether every distinction survives.
- Produce the clean copy, and confirm nothing that belongs to the drawing went with the notes.
- Hand it to someone new and ask what they would do next. That answer is the real test.
Frequently asked questions
How do you annotate a floor plan?
Decide who will read the plan and what they need from it. Choose the simplest mark for each message: a note beside the object, a leader when it cannot sit beside it, a highlight for an area, a route for a journey. Size the text for the printed scale, keep leaders short and uncrossed, add a legend for anything a reader could misread, and keep the marks separate from the drawing so you can print a clean copy.
What size should text be on a floor plan?
Work from the printed height. Multiply the height you want on paper by the scale to get the height on the plan: 2.5 mm on paper at 1:100 is 250 mm on the plan, and at 1:50 it is 125 mm. Around 2.5 mm is a common smallest size for notes, with larger text for titles and for plans read at a distance.
Does a floor plan need a legend?
It needs one when it uses a symbol, line style or colour a reader could misread. A plan with only walls, doors and room names rarely does. A plan with safety signs, keyed markers or several kinds of route does. A legend should list only what appears on that sheet.
Can I make my own evacuation plan by annotating a floor plan?
You can draw a useful plan of exits and routes, but requirements for evacuation plans and safety signs differ between countries and building types. Treat your drawing as a draft, and have it checked against your local rules by whoever is responsible for fire safety in the building.