Floor plan guide
A floor plan is a scaled drawing of one storey of a building seen from directly above, with the ceiling taken away. It shows walls, doors, windows, stairs and fixed fittings in their true positions, and it is normally marked up with room names and dimensions.
Picture the building sliced through horizontally about 1.2 m / 4 ft above the floor, with everything above the cut lifted off. Whatever the cut passes through — walls, doors, windows — is drawn as a solid line. Whatever sits below it, like a worktop or a bath, is drawn as it looks from above.
The cut height is a convention rather than a rule, and it moves when the building needs it to. A room with unusually tall windows gets cut higher, so the windows still read as windows.
Below is one house drawn four times: the ground floor of a two-storey home, 10.4 m x 8.6 m. Nothing about the building changes from one drawing to the next. What changes is how much the drawing tells you — and each of the four is the normal deliverable for a different group of people.
Also called a technical plan, a line drawing, or simply a 2D plan.
Already have this on paper? sketch to floor plan
A presentation plan in the US, a coloured plan in the UK, Grundriss farbig or Farbplan in Germany, planimetria a colori in Italy, plan coloré in France. Japanese listing plans, 間取り図, are almost always tinted this way by room type.
The fill is grouped by what a room is for, not simply set apart from the room beside it. On the plan above that makes four groups: circulation, where the entrance hall and the staircase share one wash; living space, where the living room and the study share another; the kitchen and wet rooms, where the kitchen/dining room and the cloakroom share a third; and service and storage, where the utility and the understairs cupboard share the last. Two rooms in the same group take the same colour even when they sit at opposite ends of the plan.
Worth knowing: a "2D color floor plan" in American property marketing almost always means this one, not the flat coloured plan above.
Arrives as a 2.5D overhead view, a bird's eye dollhouse or a low isometric, depending only on how far the camera drops towards the horizon.
Start from a plan you already have: floor plan to 3D model
Each level is made from the one above it and adds to it. That is why the four pictures are one house rather than four drawings of four houses: the black and white plan was drawn first, and each of the next three came out of its predecessor. The one thing that does not survive the climb is the annotation — room labels and dimension lines drop out when the drawing goes into three dimensions, which is why a 3D view is shown next to a plan and not instead of one.
Almost nobody walks the whole ladder. An architect stops at the first or the second and never needs the rest. An interior designer lives at the third and fourth. An estate agent is handed a finished first-level plan and wants a third-level one out of it. Someone with a sketch on graph paper often jumps straight to the third or fourth, skipping both drawings in between.
Three of the four words below get used for each other constantly. They describe different things.
| Floor plan | Blueprint | Site plan | Elevation | |
|---|---|---|---|---|
| What it is | One drawing: a single storey seen from above | A whole set of construction drawings, floor plans included | One drawing: the plot seen from above, building on it | One drawing: one face of the building seen straight on |
| What you learn | Room positions and sizes, and how you move between them | How the entire building goes together | Where the building sits, boundaries, access, outdoor space | Heights, roof shape, and what the outside looks like |
| The building appears as | Rooms, walls and openings | Everything, sheet by sheet | A single outline, usually with no rooms in it | A flat face with windows and doors on it |
| Typical scale | 1:50 or 1:100, or ¼ in = 1 ft | Varies sheet by sheet | 1:200 or 1:500 | 1:50 or 1:100 |
"Blueprint" is not a kind of drawing at all. It is the name of a nineteenth-century copying process that printed white lines on a blue ground, out of use for decades, and the word outlived it. Today it stands loosely for the whole set of construction drawings — so when someone asks for the blueprint of a room, they nearly always mean its floor plan.
Read the ladder backwards. Start from the job in front of you, and the drawing follows.
| What you are doing | What to ask for | Why that one |
|---|---|---|
| Sending sizes to a builder for a quote | Black and white plan | The numbers are the deliverable. Colour and furniture add nothing a quote can use. |
| Showing a client how the space is divided | Coloured plan | A wash of colour separates the zones faster than reading every room label does. |
| Listing a property in the US, Canada or Australia | Rendered plan | Buyers in those markets expect furniture and floor materials on the plan. |
| Listing a property in the UK or Italy | Black and white, or coloured | Listings there run the plain plan with room dimensions, and buyers read it that way. |
| Selling a home that has not been built yet | 3D plan | There is nothing to photograph, so the drawing has to carry the whole thing. |
| Working out whether the sofa fits | Rendered plan | Furniture at true size against real wall lengths answers it in one look. |
| Recording a house before you change it | Black and white plan | You are capturing what is there, not presenting it. The rest is decoration. |
| Showing where the building sits on its land | A site plan, not a floor plan | Boundaries, access and outdoor space live on a different drawing, where the building is one outline. |
| Handing drawings to a contractor to build from | The full set, not one plan | This is what people mean by blueprints. Floor plans are part of it, next to elevations, sections and details. |
Two of those nine rows do not answer with a floor plan at all, and that is the useful part: a good deal of what gets asked for as "the floor plan" turns out to be a site plan or a full drawing set.
Already have a plan and want one part of it changed? That is its own job, set out in how to edit an AI-generated floor plan
Four things account for most of the confusion.
A plan with no scale bar can still be read if it carries dimension lines, which is why most listing plans print the figures even when they leave the scale off.
Taking the numbers yourself rather than reading them? Start with how to measure a room for a floor plan
1:50 means one unit on the sheet is fifty in the building, so 1 cm reads as 50 cm. 1:100 is the usual choice for a whole house, 1:50 for a single room. Imperial drawings write the same idea as ¼ in = 1 ft.
Room sizes are usually written width then length, as you face into the room from the door. The convention is not universal, so when it matters, check the figure against the dimension line rather than trusting the order.
A run of dimensions may be taken to the face of a wall or to its centre line. Two drawings of the same house can carry different numbers for the same room and both be correct.
Metric plans are normally in millimetres, so 3600 means 3.6 m. Imperial plans run in feet and inches, written 12'-6".
Plan symbols are a small, stable vocabulary: heavy lines for what the cut passes through, thin lines for what sits below it, dashes for what is above.
A gap in the wall and a quarter-circle arc centred on the hinge.
A break in the wall with thin lines across it.
A line per tread and an arrow marked UP or DN.
Sanitaryware and kitchen fittings, outlined at their real size.
Short codes such as WC, DW or REF, several of which mean different things on different drawings.
Every common symbol drawn to scale, with the abbreviations and the letters that clash:floor plan symbols and abbreviations
Short answers to the things that come up most often.
Describe the rooms you have, or upload a plan or a sketch, and the drawing comes back as a PNG.
