Short answer. Sketch your home roughly first. Then measure every room inside, wall to wall at floor level, clockwise from the door, plus both diagonals, the doors, the windows and anything fixed. Draw the clean plan at 1:50 (2 cm on paper for each metre) for a flat, or 1:100 (1 cm for each metre) for a bigger house. Add the standard symbols, label each room with its size, and check a few real lengths against the plan.
What you need
A sketch pad and pencil, squared paper or an app, and something to measure with. A flat takes an afternoon.
| Tool | Typical accuracy | Best for |
|---|---|---|
| Steel tape measure | About 1 to 2 mm | Kitchens, fitted wardrobes, anything made to size |
| Laser measure | About 2 to 3 mm | Long walls, measuring on your own |
| Phone camera | A few centimetres | Planning furniture, quick checks |
More on phones in how to measure a room with your phone.
Step 1: sketch it, not to scale
Draw each room as a box roughly where it sits, with its doors and windows: one sheet per floor, big enough to write numbers along every wall.
Step 2: measure in the same order in every room
Number the walls clockwise, starting with the wall that has the door, and measure each one: opposite walls often differ by a few centimetres. Then, in this order:
- Both diagonals, corner to opposite corner (below).
- Doors: distance from the nearest corner, width, which way it opens, which side the hinges are.
- Windows: distance from the corner, width, sill height.
- Wall thickness, across a door frame. Roughly 10 cm for a stud wall, 30 cm for a brick and block outside wall, but measure yours.
- Ceiling height and fixed things: radiators, boiler, chimney breast, boxed-in pipes, stairs.
Use one unit and do not round: 342 cm, not "about 3.4 m".
Equal diagonals mean square corners. If they differ, the room is out of square and your plan should show it.
Step 3: choose a scale
| Scale | 1 m on paper | Good for, and what fits on A4 |
|---|---|---|
| 1:20 | 50 mm (a 5 mm square is 10 cm) | One room in detail, such as a kitchen: about 5.3 × 3.6 m |
| 1:50 | 20 mm (a 5 mm square is 25 cm) | A flat or one floor: about 13.3 × 9.0 m |
| 1:100 | 10 mm (a 5 mm square is 50 cm) | A larger house: about 26.7 × 18.0 m |
Pick the largest scale that fits a whole floor on one sheet; A3 fits about twice as much as A4. The tool at the top shows how big a room comes out on paper.
Step 4: draw the walls
Largest room first: inside lines in pencil, then the wall thickness outside them (at 1:50 a 10 cm wall is 2 mm). Add the rooms next door, then halls and cupboards, which show up mistakes. Pen when it all fits.
Step 5: doors, windows and symbols
- WallSolid, at its real thickness: thick outside, thin inside
- DoorThe line starts at the hinge; the arc is the floor it sweeps
- Sliding doorA panel along the wall where it slides
- WindowTwo or three thin lines across a gap
- RadiatorA thin rectangle standing off the wall
- StairsA line per step, the arrow points up
Draw door arcs at the door's real width. Double doors have two arcs, an open doorway none; kitchen units are a band about 60 cm deep. More in how to read a floor plan.
Step 6: label it and check it
Write each room's name and size (Bedroom, 3.42 × 2.95 m, 10.1 m²), the scale, the floor, the date and a north arrow if you know it. Then check:
- Add up a line of rooms. Kitchen 3.10 m + a 10 cm wall + living room 4.20 m + two 30 cm outside walls = 8.00 m. If the outside measures 8.40 m, something is missing.
- Measure one length off the plan with a ruler, convert it back and compare it with the tape.
- Walk round with the plan. Every door, window and radiator should be where it says.
A worked example: one bedroom
Walls clockwise from the door: 3.42, 2.95, 3.40 and 2.96 m. Diagonals 4.50 and 4.53 m, against 4.52 m for a true rectangle: about 3 cm out of square, fine for furniture. A 762 mm door 10 cm from the corner, a 1.20 m window with a radiator under it, walls 10 cm thick. At 1:50 the room is 68 × 59 mm on paper; at 1:100 only 34 × 30 mm, too small to write in.
A 135 × 190 cm double with its head on wall 2 leaves 80 cm each side and 1.52 m at the foot, clear of the door's arc.
Which way to make it
| Way | Time for a flat | Best when |
|---|---|---|
| By hand on squared paper (free) | An afternoon | A quick sketch or a council form |
| Draw it in an app (usually free for one plan) | 20 to 60 minutes after measuring | You want to try furniture or share it |
| Scan the rooms with your phone (usually free) | 5 to 10 minutes a room | You are in the home with no plan |
| Let an app read an existing plan (often one free reading) | A few minutes, then checking | The agent or landlord has a plan |
| Pay someone | Varies | Planning applications and building work |
Ask for an existing plan first: agents, developers and landlords often have one. If you have it, turn that plan into 3D.
Floor plans UK councils ask for
- HMO licence and housing forms. A simple sketch is usually enough: each room labelled with its rough area, kitchens and bathrooms, and for an HMO the fire doors and smoke alarms. Cherwell suggests about 1 cm for each metre; Croydon says the plan need not be to scale.
- Planning applications. Existing and proposed plans at 1:50 or 1:100 with sizes or a scale bar, usually drawn by an architect.
Each council sets its own list, so read yours first.
Common mistakes
- Measuring only two walls. Opposite walls differ.
- Forgetting the wall thickness, which makes the whole plan too short.
- Mixing units, or measuring to the skirting instead of where the walls meet.
- Skipping the diagonals or the door swings. Without them you cannot tell if the wardrobe fits.
Make it in Flatwalk, then walk through it
Flatwalk is a phone app that makes the plan and then lets you stand in it. Draw the walls and type each inside length, use "Scan your whole room" to tap the corners through the camera, or upload a photo, screenshot or PDF of a plan for the reader (the first reading is free; "Draw it myself" opens an empty plan if it cannot read one).
Then walk through it in 3D, place real shop furniture at its true size and read any gap with the tape measure. It is for planning your own home, not for council drawings, and only as true as the sizes you give it. Coming soon to Google Play.
More on floor plans: how to read a floor plan, measure a room with your phone and floor plan to 3D.
What Flatwalk does that older planners skip
Lights
Add ceiling lights, lamps and LED strips to the plan you drew and see each room in the evening, not only by day.
Your flat in its city
Give the address and the street and buildings around you appear in 3D where the map has them.
Sun for your address
See where the sun falls through your windows by date and hour.
One piece, in your own room
Through the live camera or in a photo of the room, stand it on your own floor at its true size before you buy.
Detail
Doors, radiators, kitchens, wardrobes and bathrooms built piece by piece, so new furniture meets what is really there.
Made for a thumb
Tap a wall and type its length; tap a piece to move it, turn it or replace it.
Swipe for more. Every picture is the app itself.
One flat, free
Most people plan one home. For that, Flatwalk costs nothing: no trial clock and no card. Drawing your flat, exact wall sizes, room scanning, furniture at its true size, the tape measure, lights, sun and walking are all part of it, and each AI tool, reading a floor plan picture among them, gives one free try. A membership is for people who want more flats or more AI.
Questions people ask
Can I draw my own floor plan? Yes. With a tape measure, squared paper and an afternoon you can draw a flat: measure each room inside, sketch it, draw it at 1:50 and check a few lengths.
What scale should a floor plan be? 1:50 for a flat or one floor of a small house (1 m is 2 cm on paper), 1:100 for a larger house (1 m is 1 cm), 1:20 for one room in detail.
How do I measure a room for a floor plan? Every wall inside the room at floor level, clockwise from the door, then both diagonals, the doors and windows from the nearest corner, the wall thickness at a door frame, the ceiling height and anything fixed.
Should floor plan measurements be inside or outside the walls? Inside, wall to wall, because that is the space furniture needs. Then draw the walls at their real thickness around those lines.
Can I make a floor plan on my phone? Yes. Draw it in an app and type the lengths, or scan each room by tapping its corners. Check one wall with a tape, because a phone's camera is accurate to a few centimetres.
Flatwalk turns your measurements, a scan of each room or a photo of your plan into a flat you can furnish and walk through, free for one flat. It is coming soon to Google Play; join the waiting list at flatwalk.app.
Join the waiting list