Sound Smarter on the Jobsite: Tolerance
No, this isn't about dealing with something or someone you're not keen on. This is about *construction* tolerance: the exactness or perfection you can expect from real world materials and assemblies.
Materials and assemblies in construction aren't perfect, and they don't always have to be. How "perfect" they have to be for you to accept them as good enough is what "tolerance" is about. For example, structural concrete's accepted tolerance is about 1/4" over 8'. That means that over the course of 8', your concrete footing or wall might be out of plumb or square by 1/4", and that's OK. Structural concrete is a rough material that's tough to get perfect, and it doesn't usually directly interface with finishes that have tighter tolerances. That said, if you Google "acceptable concrete tolerances," you get a ton of info, debate, and specific cases and conditions. Do not take the numbers in this thread as gospel, but rather, as illustrative of the concepts.
In cabinetry and trim work, the tolerances are *much* tighter - first, cabinetry is easier to be precise with, during construction and install. Second, giant gaps and crookedness which would be hidden in structural concrete are front and center in finish cabinetry. Can't have that!
This is where we get into “personalities” of different subs. Your concrete guy is going to be a bit rougher/less precise than your cabinet guy [not personally, just in the work they do!] Your cabinet guy is going to be running around w/ calipers while the concrete guy might grab a straightish 2x4 from the pile as a level. Same thing with a framer vs a finish carpenter. It's all because of tolerance. Generally the closer the material is to being "seen" (finishes, fixtures) the smaller and more precise the tolerances are, and the more precisely made the materials are.
So when you go on a jobsite, you have to adjust your expectations for perfection according to the work that's going on. It shows that you understand construction as a whole, and you understand industry expectations around different trades.
That said, there are times when you need to push beyond industry standard requirements. This happens a lot in framing. In a run-n-gun tract home with standard finishes vs a high end renovation with precise/fancy finishes, there is a different level of owner expectation. Precise framing, especially in areas with tile, stone, fine cabinetry, trim, etc, will make the finish folks' job a lot easier. This applies in less fancy projects as well, but often the level of sub you can get on those jobs means you'll have to settle for a lower level of craft.
Tolerance applies to the work architects do as well (no, not just because you tolerate them...) If an architect understands construction, and understands the needs of the people onsite, she will know how to draw details such that they account for tolerance.
Just like assemblies (concrete walls or framing), materials also have tolerance. A sheet of plywood or a 2x4 has a certain amount of slop that's allowed in the material dimensions...aka they're not straight. That means she needs to account for some of that slop in her drawings. All new architects learn this: you draw perfect lines in the computer, but that doesn't usually translate. Drawings are like jeans: some (cabinet details) are the equivalent of skinny jeans, some (foundations) are like relaxed fit. Gotta know which you need and when.
You can tell a seasoned architect by how much she's asking for stuff to line up perfectly: too much of that, she's a newbie. What we do is ask that only a few things line up perfectly; the rest, we use clever reveals to hide the realities of materials/level of craft.
Here's what I mean. In this kitchen, we did the soffit (chunk above the cabinetry) with millwork, meaning the cabinet guy would be installing it. That meant we could get it exactly lined up with the face of the cabinetry. But, we don't carry the cabinet all the way to the ceiling, because the ceiling is sloped, and has looser tolerance. So the soffit takes up the difference, rather than us expecting a perfect ceiling. Also notice how we held the shelf back from the front of the cabinet face. Again, tolerances. And also, design: we wanted a shadow line there.
Here's one with a drywall/plaster soffit. These we always hold about 3/4" past face of cabinet door, because plaster is notoriously wavy, and we don't want your eye drawn to that misalignment. Separate them, and problem solved - easier for the installers, better looking...win win.
There are about 147 other examples of the understanding of tolerance in those images alone - it's a construction concept that comes up daily, and is a very easy tell that someone doesn't understand stuff. Architects need to understand this and so do owners. Construction happens in the real world, and the talent of your architect and GC lies in their ability to manipulate real-world conditions to achieve amazing results. Owners, your job is to understand to what level you can demand "perfection" on different areas of the project.
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