Can I draw crooked rooms, or does a floor-plan app lock everything to 90 degrees?
Most rooms SHOULD be square, and a small nudge from the app makes them so. But some rooms genuinely aren't square — and then that snapping has to be switchable, or you end up drawing a lie.
Short answer: Yes, you can draw crooked rooms — but it requires the app to give you an opt-out, not just a helper tool. A good drawing app snaps corners to 90° by default, because the vast majority of rooms genuinely are square, and a drawing made with a finger on a screen otherwise easily ends up 87° in one corner and 92° in the next without you noticing. If your room is genuinely off-square — an old timber-framed room, an extended corner, a room drawn to follow a skewed plot — you need to be able to switch the snapping off for that specific corner or wall, while the rest of the drawing is still held square.
Why most rooms genuinely are square
It sounds obvious, but it's worth saying out loud: the vast majority of rooms in the vast majority of buildings are drawn, measured and built with square corners. It's cheaper to build, it's easier to furnish, and it's how a carpenter sets up a wall — with a set square or a 3-4-5 measurement. Off-square corners are the exception, not the rule.
That also means that when you draw a room by hand — with a finger or a mouse on a screen, with no tape measure in your other hand — the biggest source of error isn't that the room is actually crooked. It's that you draw it crooked, because a finger on glass doesn't land on exactly 90.0° to within 0.3 mm. Without help, an attempted square room typically ends up somewhere between 85° and 95° in each corner, and that kind of error stacks up the more walls the room has.
What angle-snapping actually does
A good square-angle snap works while you're drawing, not afterwards. As you drag a new wall out from a corner and it approaches 90° relative to the previous one, the line "snaps" to exactly 90° — like a magnet pulling the last little bit into place. Drag clearly off-angle, on purpose, and the snap lets go, letting you draw the actual angle you're pointing at.
That does two things for you at once:
- It corrects the kind of error you can't see yourself. A corner that's 2° off square looks square on a phone screen. It doesn't in a floor plan, where two millimetres of error per metre of wall stack up across the whole room, and a 5-metre room can end up off enough that a kitchen unit won't sit flush against the wall.
- It keeps the room "honest" when you're NOT trying to hit 90°. If you deliberately drag a crooked wall — because the room genuinely is like that — the app shouldn't pull it back to square behind your back. The snap has to be able to tell the difference between "you're aiming for square and nearly hitting it" and "you're clearly aiming somewhere else".
When is a room genuinely off-square?
Some rooms aren't drawn wrong — they're built crooked. The main reasons:
- The plot is off-square. If the building plot isn't rectangular, the house's outer walls often follow the plot's lines, and a corner room can end up with an angle of 80-85° instead of 90°.
- Renovations and extensions. An extension built along a boundary line or an existing path often inherits a different angle from the original house.
- Older building traditions. Timber framing and older craftsmanship without laser measuring rarely holds 90° to the decimal — and in some places a slightly crooked wall is part of the house's character, not a fault to be fixed.
- Decades of settling. A house that has settled unevenly can have corners that are no longer square, even though they were when it was built.
- Deliberate architecture. Bay windows, oriels and angled extensions are often drawn off-square on purpose, to make the most of light or a view.
In every one of those cases, a drawing that forces the room square gives you a wrong area and a plan that won't match up when a contractor or a piece of furniture has to go into the room. If the room is genuinely off-square, the drawing has to be too.
How to find out if YOUR room is off-square
You don't have to guess. Three methods, in rising order of precision:
- The diagonal method. Measure both diagonals in the room. If the room is a true rectangle, the two diagonals are the same length. If the difference is more than a couple of centimetres in a 3-4 metre room, something is off — either a corner that isn't 90°, or walls that aren't parallel.
- A set square, or an app with a level. A physical set square held up to the corner quickly shows if there's a gap. Many phones also have a built-in angle meter in the compass app, which can be used for a rough check.
- A 3D scan. If you scan the room with LiDAR, the scan draws the corners as they actually are — off-square ones included. It's the most precise method, because it doesn't rely on you spotting the skew yourself.
If the difference is under a centimetre in an ordinary room, it's probably your own measuring error or a normal building tolerance — not a room you need to draw off-square.
What happens if you draw a square room wrong, as crooked?
The opposite problem exists too: you think the room is off-square, because your own drawing or measuring wasn't precise, and end up drawing a skew that doesn't actually exist. The consequence is the same as the other way round — an area that doesn't add up, and a plan that doesn't match a piece of furniture that would actually have fit flush.
Rule of thumb: if you're unsure, leave the snap on. It catches the vast majority of everyday errors. Only switch it off when you have a concrete measurement — a diagonal, a set square, a scan — showing you that the room actually deviates from square.
What HouseSense does
On the drawing board in HouseSense, "Snap to square angles" is switched on by default when you draw a floor plan with your finger. Drag a wall close to 90° relative to the previous one, and the app corrects that last little bit for you. If the room genuinely is off-square, you can switch the snap off and draw the actual angle you're pointing at — the feature exists precisely because not every house is square, and a drawing must not lie about it. If your phone has LiDAR, you can scan the room instead, so the corners come through as they actually stand, without you having to spot the skew yourself.
Crooked rooms and load-bearing walls
One last caveat: neither a drawing app nor a scan can determine whether a crooked wall is load-bearing, or whether a skew in the house is caused by settling that is still ongoing. An angle that isn't 90° is a geometric fact — not a structural assessment. If you're unsure why a corner is off-square, or whether it matters for the house's stability, that's a job for a building surveyor or an engineer, not a floor plan.