Circulation is the route people take through a room. To read a plan for it, convert the scale to real sizes and check that the paths between furniture are wide enough.
This lesson is part of the SPM subjects and learning resources collection for Interior Decoration.
Step 1: convert the scale
Multiply each plan measurement by the scale number. On a 1 to 50 plan, 1 cm on paper is 50 cm in the room.
Worked example: a fictional living room
All numbers are invented for practice. The room plan is 8 cm by 7 cm at a scale of 1 to 50.
- Room length: 8 × 50 = 400 cm = 4.0 m.
- Room width: 7 × 50 = 350 cm = 3.5 m.
- Room area: 4.0 × 3.5 = 14 m².
The furniture, in real sizes:
| Item | Size | Area |
|---|---|---|
| Sofa | 2.0 m by 0.9 m | 1.8 m² |
| Coffee table | 1.0 m by 0.6 m | 0.6 m² |
| TV unit | 1.5 m by 0.4 m | 0.6 m² |
Total furniture area: 1.8 + 0.6 + 0.6 = 3.0 m². As a share of the floor: 3.0 ÷ 14 = 0.214, which is about 21%. That leaves roughly 79% of the floor free.
On the plan, the sofa is drawn at 2.0 m ÷ 0.5 = 4 cm by 0.9 m ÷ 0.5 = 1.8 cm. Dividing by 50 cm per plan cm gives the drawn size.
Step 2: check clearances
The TV unit sits against one 3.5 m wall. The sofa faces it across the 4.0 m length.
Space between the walls. Sofa depth 0.9 m, table depth 0.6 m and TV unit depth 0.4 m add to 0.9 + 0.6 + 0.4 = 1.9 m. The remaining length is 4.0 − 1.9 = 2.1 m, which is shared between the gap from sofa to table and the gap from table to TV.
Walkway beside the sofa. The room is 3.5 m wide and the sofa is 2.0 m wide, so the space beside it is 3.5 − 2.0 = 1.5 m. This is wider than the 90 cm practice guide, so people can pass.
The mistake that costs marks
The slip is judging the plan by eye. A plan with furniture on every wall looks organised, but it may leave no usable path.
Suppose the student adds a bookshelf 1.0 m wide beside the sofa.
| Step | Wrong | Right |
|---|---|---|
| Check | “It looks fine” | 1.5 − 1.0 = 0.5 m, then compare with 0.9 m |
| Result | Accepted | 0.5 m is below the 0.9 m guide, so the path is too narrow |
| Fix | None | Move the shelf to a different wall or use a slimmer unit |
The fix is to subtract each item from the width and compare the remainder with your stated guide.
What to write in an exam answer
Write the scale conversion, the furniture sizes, the remaining space and the comparison with the guide. Then state your decision.
“The remaining walkway is 1.5 m, which is more than 0.9 m, so circulation from the door to the sofa is clear.” That sentence links the number to a conclusion.
Furniture relationships
Circulation is one part. Relationships also matter. The sofa faces the TV so people can watch comfortably, and the coffee table is within reach of the sofa.
A gap of 40 cm between sofa and table is a common guide for leg room, so check that your table sits close enough to reach and far enough to pass.
Check yourself
On a 1 to 50 plan, a bedroom is 6 cm by 5.5 cm. A bed 1.5 m wide is placed against the short wall. The room’s width is the 5.5 cm side. How much wall space remains beside the bed, and is it at least 90 cm?
Answer
Real width: 5.5 × 50 = 275 cm = 2.75 m.
Remaining beside the bed: 2.75 − 1.5 = 1.25 m.
1.25 m is 125 cm, which is more than 90 cm, so the space is wide enough.
What to study next
Go on to justifying a colour and material concept using a stated design brief, then review your written working with the structured-answer self-review tool.
Practical design work stays with your school. If you want a teacher to check your plans with you, see online one-to-one Interior Decoration tuition.