Can I draw the home now and scan it later?
Yes. A drawn home is a fully valid starting point, and you can scan rooms into it afterwards as you get to them. Here is the order that causes the least rework.
Short answer: yes. Draw the home based on what you know now — a sale listing, an old floor plan, a few measurements on a note — and scan the rooms in once you are standing in the home. A scanned room is a measurement and should take precedence over a drawn estimate of the same room. The most efficient order is therefore: draw roughly first to get an overview, then let the scan overwrite it room by room afterwards.
Why it makes sense to draw first
There are three situations where drawing naturally comes first:
You are thinking about buying. You have seen a sale listing and want to know whether the furniture fits before spending a Saturday on the viewing. A rough drawing of the rooms answers that in ten minutes on the sofa at home.
You are planning a renovation. You want to see what happens if the wall between the kitchen and living room comes down. That can only be drawn — there is nothing to scan yet.
You don't have LiDAR right now. Maybe you're borrowing an iPad Pro next week, or maybe someone else in the family needs to do the scanning. The drawing keeps the home moving forward in the meantime.
Rule number one: measured beats guessed
When you later scan a room you have already drawn, the question arises of which version should stand. The rule is simple: a measurement beats an estimate.
If you drew the living room as 4.50 × 5.20 m from a sale listing, and the scan says 4.44 × 5.18 m, the scan is closer to reality — it has actually been in the room. Keep the scan's figures, and delete your own version of that room, so there are not two copies lying around.
The only exception is if you can see the scan measured something wrong: a wall sitting where the curtain hung, or a door landing 40 cm off. Then you correct the scan on the drawing board with your own tape-measure figure — not with the old estimate from the listing.
The order that causes the least rework
- Draw the home roughly. The rooms in their correct positions relative to each other, with the measurements you have. Don't worry about centimetres yet — the goal is an overview and a place to hang the rest on.
- Note what is a guess. Feel free to give the room a name that says so, or write a note. What isn't measured needs to stay recognisable from what is.
- Scan when you are standing in the home. Take the rooms you can walk around in, and move calmly along the walls.
- Replace room by room. Each scanned room takes over from its drawn version. Delete the old one straight away.
- Finish drawing the rest with a tape measure in hand while you are there: the garage, the storage room, the locked room.
- Put it all together and let the walls snap, so neighbouring rooms share a wall instead of counting the same square metres twice.
The maths: how far off an estimate typically is
You draw a living room from the sale listing: 4.50 × 5.20 m = 23.40 m². When you scan it, it turns out to be 4.44 × 5.18 m = 23.00 m². The difference is 0.40 m², so under 2%.
For paint and flooring, that 2% has no practical effect — it disappears into the 5-10% waste allowance you add anyway. But if a 4.48 m shelving unit needs to fit along the short wall, the difference is decisive: by your estimate it fits, by the measurement it doesn't.
That is the whole point of letting the scan overwrite the drawing: the estimate is good enough to plan with, and not good enough to order against.
The other way round: scan first, draw the rest
The order also works in reverse, and it is actually the more common one. Scan the home while you are there, and draw in afterwards the rooms you couldn't get to — plus anything that doesn't exist yet.
The advantage of that order is that the scan sets the geometry first. The drawn rooms then just need to be set against something already measured, which is easier than adjusting a whole scanned floor to fit a drawing.
The rule is the same either way: let what is measured decide, and move what is guessed.
What you lose by drawing first
Be honest about the downside. A drawing only knows what you yourself have seen. Draw a home from a sale listing and you get four right-angled walls per room — not the chimney breast, not the pier, not the niche behind the door, and not the 6 cm the room is out of square.
That means a drawn home often looks tidier than the scanned version of the same house. It isn't better; it just doesn't show any doubt. If you later get the chance to scan it, the floor plan will become messier and more correct at the same time. Let it.
Practical things you can do in the meantime
A drawn home is not a placeholder. Everything the home can do in HouseSense already works:
- area per room and for the whole home, floor by floor;
- a floor plan with measurements that can be passed on as a PDF;
- takeoffs for contractor quotes — wall surfaces, floor surfaces, ceilings, number of doors and windows;
- a 3D model you can walk around inside;
- sunlight based on the address and north direction, if you place the house on the map;
- budget and reports.
All the figures get better once the rooms are later scanned — but they are usable from day one, as long as you know which of them are measured and which are guessed.