How big of a space can I scan?
The Short Answer
There is no specific limit on how big of a space you can scan, and a lot of factors affect how quickly memory is consumed during a scan (amount of detail in the space, scan technique, available RAM on your iPad, etc). For example, a complicated but small kitchen might eat up memory faster than a large but empty bedroom. This is why for the best, most consistent results, we always recommend scanning spaces one room at a time. Doing so will generally be the most accurate, consistent, and easiest way to scan with good results using the scanning technique we describe in our scanning tutorial video.
If you are using Scan To CAD, you can also merge multiple scans into a single, global model of an entire property (or sections of a property), and there is no real limit on the number of scans you can merge — we've processed orders of 50+ scans several times. However, if you are merging a very large number of scans (say, 35+), that can introduce additional sources of error above our typical accuracy tolerances. Small error in wall thickness (which Canvas does not directly observe, so we apply construction standards) can compound across a very large property, and if the scans are poor or don't completely line up, that can require some assumptions and guesswork. That being said, the majority of our orders are merge orders, so we're quite proficient with this process, and customers are usually very pleased with the results, quality, and time-savings.
For more information on merging scans or capturing entire homes, we recommend reading: Can I merge multiple scans to cover an entire property?
So, what counts as a room?
A common question that arises from this is, "Well, what counts as a room?" In most cases, it is how you'd think about is as a homeowner: the living room, the kitchen, the bedroom, the bathroom, etc. However, Canvas does not require you to be extremely strict about this, and it is ultimately up to you how to break up a property into multiple scans.
For example, you can usually scan a walk-in closet in the same scan as its bedroom without issue, or even capture small bathrooms connected to a hallway. Staircases aren't really a "room" but can often be scanned with the contiguous hallways or open spaces. At the same time, if a room is very large (but still residential-scale, like a big open living room, or a large basement), you may need to break the room into two or more scans (don't worry, if you are using Scan To CAD we can merge it for you later). Generally speaking, though, any Canvas-compatible iPad with 2GB of RAM or higher should be able to, on average, handle most residential-sized rooms in one scan.
The three most important things are that you:
- Capture all sections of the home that you expect to show up in your CAD model somewhere in your individual scans
- Scan through connecting areas (like doorways) into the adjacent space (if you do intend to merge it with other scans)
- Avoid zig-zagging in and out of many rooms in a row within a single scan
Important: As we price per scan, we know that it is technically cheaper to try to cram as many rooms as possible into a single scan. However, the zig-zagging in and out of rooms can often lead to significantly worse scan quality, which is likely to lead to a much less accurate Scan To CAD result. Moreover, it leads you to not "plan your scan" and do things like turn lights on and open doors in the middle of the scan — both of which can severely affect your results. If you ever feel like you took more scans than may have been necessary to capture a given space (for example, to be extra-cautious and capture everything), feel free to request a review of your order by emailing firstname.lastname@example.org.
In commercial or industrial settings, a "room" might be a giant open office space or theater that could require a dozen or more scans. An extremely loose rule of thumb is that a typical scan can cover around 400 square feet before running out of memory on a typical iPad, but this is very much an estimate and subject to vary widely. Every space is going to be different, and one of the reasons why we say Canvas is optimized for residential spaces is that it's harder to confidently predict the number of scans or the best approach to scanning very large, open spaces. It certainly can and has been done, but it's often going to require a bit more trial and error to determine the right scan path (don't worry, we'll help), and you may run into other limitations which you can read about here: I want to scan non-residential environments. Will Canvas work outside the home?
If you are regularly scanning large, open environments, you may also be interested in the PX-80 by Paracosm (another division of Occipital, the makers of Canvas), which, while more expensive, is purpose-built for these kinds of environments.
How many scans will it take to cover a full house?
This then leads to the question: "Well, how many scans will I need to scan a full house?" Again, it depends. Every home is different, and it's not simply the size that matters, but generally speaking the average full home that we see is about 8-12 scans. We've seen over 30 and we've seen as few as 3-4 for small apartments, but "typical" tends to be about 8-12.
One reason the number of scans can vary is the complexity of the home. For example, a small, extremely ornate and complicated home with lots of nooks and crannies to capture may eat up memory faster, and therefore require more scans than a larger (but more open) home. Another factor is scanning technique: if you try to capture every piece of furniture, from every side, and fill in every small hole, your scans will consume more memory, faster (and therefore require more to cover a property in full). However, if you are scanning to eventually convert the files into CAD, you are actually better off sticking to the perimeter of the room, avoiding the center except where there are important built-in items (like kitchen islands) because the furniture will get cleared out in Scan To CAD anyway. This avoids using up memory unnecessarily, but it's also going to be more conducive to the best practices shown in our scanning tutorial video.
(Tip: You also don't need to scan the floor or ceiling at all, except up to where they meet the walls and enough to determine the angle, because then we can tell that a flat plane is supposed to go there. An important exception to this, however, is when there is detail on the ceiling or floor that you want to ensure shows up in your final CAD model like steps, trays, architectural detail, vaulted ceilings, beams, etc. In this case, you definitely should capture those in your scan. This is a very easy and common way you can optimize your memory usage to require less scans.)
Help! I keep getting a low memory warning when I scan!
If you have read the above and are still getting this warning when you think you shouldn't be (i.e., you are running out of memory before you can capture a typical residential room, and you have already optimized your scanning with the tips above), please read Help! Canvas keeps telling me that I'm running out of memory.