How to Draw a Floor Plan of Your Home

Last updated: 13 September 2026

Drawing an accurate floor plan of your own home takes about two hours and needs a tape measure, paper and a pencil. Sketch each floor freehand without worrying about scale, measure every wall and opening, check each room's diagonals to find out how far from square it really is, then redraw to scale — on paper at 1:50, or in software that handles the scale for you. The measuring is the work. The drawing is the easy part.

The single mistake that ruins amateur floor plans is assuming rooms are rectangles. Almost none are.

What you need

Four things, and you probably own three of them.

A tape measure, 5 m or longer. A laser distance meter costs around €25–40 and makes this dramatically faster and more accurate, particularly for long walls where a tape sags.
Paper and pencil. Graph paper helps but is not required for the first pass, which is deliberately not to scale.
A second person, for anything over 4 m. Not essential. Very helpful.
Somewhere to put the finished plan — squared paper, or floor plan software.

In short: buy the laser meter if you are measuring more than three rooms. It pays for itself in an afternoon of not holding one end of a tape against a skirting board with your foot.

Step 1 — Sketch it freehand, badly, first

Walk each floor and draw its outline on one sheet of paper, one sheet per floor, with no attempt at scale or straight lines. Mark every room, every doorway, every window, and every immovable thing: the boiler, the stack, the consumer unit, the radiators.

This sketch exists to be written on. Its only job is to give every measurement a place to land, so that you are not holding twenty numbers in your head while standing on a chair.

Draw it bigger than feels necessary. A cramped sketch is where measurements get written on top of each other and become unreadable an hour later.

Step 2 — Measure every wall

Measure each room wall by wall, going clockwise so you never lose your place, and write each number directly onto the sketch as you take it.

Rules that matter more than they sound:

Measure wall face to wall face, at about waist height. Skirting boards, coving and uneven plaster all lie to you at floor and ceiling level.
Work in millimetres or centimetres, never in fractions. Mixing units is the most common source of a plan that will not close.
Measure the whole wall, then the parts. Take the full 4,240 mm run first, then the door and the gaps within it. The parts must sum to the whole, and when they do not, you have caught an error while you are still in the room.
Record the ceiling height in each room. It changes more often than people expect, especially upstairs and in extensions.

Step 3 — Check the diagonals

This is the step that separates a plan that closes from one that does not, and almost every guide omits it.

Measure both diagonals of each room, corner to opposite corner. In a true rectangle the two diagonals are exactly equal. They almost never are. A difference of 10–20 mm is normal in any building; 50 mm or more means the room is visibly out of square and you need to decide what to do about it.

Why it matters: if you draw an out-of-square room as a rectangle, the error does not stay in that room. It propagates along the wall it shares with the next one, and by the far side of the house your plan is 100 mm wider than the building. That is the moment people give up and conclude they measured wrong.

What to do with the discrepancy:

Under 20 mm — ignore it. Draw the rectangle. Nothing you plan at this scale will care.
20–50 mm — draw the rectangle, but note it on the plan. It will matter for a fitted wardrobe or a kitchen run, and not for anything else.
Over 50 mm — draw the room as its true four-sided shape. Most floor plan software has a free-form or polygon room tool for exactly this.

The key takeaway: your house is not square, and finding out by how much takes four extra measurements per room.

Step 4 — Measure the doors and windows properly

An opening needs three numbers, and most people take one.

Its width — the structural opening, not the door leaf.
Its offset — the distance from the nearest corner to the edge of the opening. Without this you know a door exists but not where it is, and a door 200 mm out is the difference between a sofa fitting and not.
Its sill height, for windows — the height from floor to the bottom of the opening. This decides whether a desk, a radiator or a worktop can go under it.

Also record which way each door swings and into which room. A door swinging into a small bedroom sterilises about 0.8 m² of it, and that is often the deciding fact in a layout.

For reference, common interior door widths: 730, 830 and 930 mm in France and much of continental Europe; 762 mm (2 ft 6 in) in the UK; 32 inches (813 mm) in the United States, which is also the usual accessibility minimum. If your measurement is close to one of these, it is probably that one and your tape was slightly off.

Step 5 — Account for wall thickness

Beginners draw walls as lines. Real walls are between 70 mm and 400 mm thick, and the difference is a whole cupboard's worth of floor area across a flat.

Rules of thumb, to be confirmed by measuring:

Interior partition (stud or single-leaf block): 70–120 mm
Interior masonry wall: 100–200 mm
Load-bearing or party wall: 200 mm or more
Exterior wall with insulation: 300–400 mm

The easy way to find out without opening a wall: measure a doorway's depth, from one face to the other. That reveal is the wall's thickness, and it takes five seconds.

Step 6 — Redraw it to scale

Now the plan becomes a plan.

On paper, use 1:50 for a single room or a small flat — one centimetre on the page is 50 cm in reality, so a 4.2 m wall is drawn 8.4 cm long. Use 1:100 for a whole house, where the same wall becomes 4.2 cm. On 5 mm graph paper at 1:100, one square is a neat 50 cm.

In software, you type real dimensions and the scale takes care of itself, which is most of the reason to use it. It also means you can change your mind about a wall without redrawing the sheet.

Draw in this order — it fails earlier and cheaper:

The exterior outline of the whole floor
The interior walls, with their real thickness
The door and window openings, with their offsets
Fixed items: stairs, boiler, stack, radiators
Furniture, last

Step 7 — Check it closes

Add up the room widths plus the wall thicknesses along one straight run of the house, and compare the total against the exterior measurement of that same run.

They should agree within about 50 mm. If they do not, something is wrong, and it is almost always one of three things: a wall thickness you assumed rather than measured, a room drawn as a rectangle that is not one, or two measurements taken in different units.

Do this before you furnish anything. Every error you leave in place gets multiplied by every decision you make on top of it.

Five mistakes that spoil an otherwise good plan

Assuming rooms are rectangles. Covered above, and worth repeating, because it is the one that makes people abandon the exercise.
Measuring at floor level. Skirting boards typically add 15–20 mm per side and turn a 3,000 mm room into 2,965 mm.
Forgetting door swings. A plan without swings looks finished and hides the reason your layout will not work.
Ignoring ceiling height. Every plan is 2D, but sloped ceilings, beams and bulkheads decide what can physically go where — especially in a loft.
Furnishing before checking. An hour spent arranging furniture on a plan that is 100 mm out is an hour spent twice.

Frequently asked questions

How long does it take to draw a floor plan of a house? Roughly two hours for an average three-bedroom home: about 90 minutes measuring and 30 minutes drawing. A single room takes 15–20 minutes. Measuring is the overwhelming majority of the work, which is why doing it carefully once is faster than doing it twice.

What scale should a floor plan be? Use 1:50 for a single room or a small apartment, and 1:100 for a whole house. At 1:50, one centimetre on paper equals 50 centimetres in reality; at 1:100, one centimetre equals one metre. Architects also use 1:20 for detailed drawings such as kitchens and bathrooms. Floor plan software handles the scale for you and only asks for real dimensions.

Do I need an architect to draw a floor plan? Not to draw one for your own use — planning a renovation, arranging furniture, or explaining an idea to a builder. You do need a qualified professional for anything official: a planning or building permit, a structural alteration, or a legally binding statement of floor area. A plan you draw yourself is for thinking and communicating, not for certifying.

Should I measure in metric or imperial? Use whichever your building was built in, and never mix them. Metric is easier because everything is a decimal and mistakes are visible; imperial fractions are where arithmetic errors hide. If you are in the US, work in inches throughout rather than in feet and inches.

How accurate does a floor plan need to be? For furniture and layout planning, ±50 mm across a room is fine. For fitted joinery — a kitchen, a wardrobe, a bookcase — you need ±5 mm, and you should measure that particular run three times. For anything structural, you need a professional survey. The key difference is that layout tolerates error and joinery does not.

Can I draw a floor plan from a photograph or a phone scan? Partly. LiDAR-based scanning apps on recent iPhones and iPads produce a usable rough plan in minutes and are genuinely good for a first pass. They are not reliable to the millimetre, they struggle with glass and mirrors, and they still need the diagonal check. Treat a scan as a fast Step 1, not as a finished plan.