Or if it's made of stone. Stacking giant stones on top of each other is a sure-fire way to make a building outlive you.
After that, the longest-lived buildings that I am aware of are made of wood. The catch is they've been rebuilt 50 times, once per time they burned to the ground.
After those, the longest-lived buildings are made of Roman concrete that we can't reproduce. (To give you an idea how insane Roman concrete was, you can go kayaking north of Naples, and kayak through a concrete Roman building that is sitting on piles in the Mediterranean sea)
The materials are important, but they can be misused, and master craftsmen can use them far better than I ever will, So the methods matter as well.
_edit_
I looked it up, hoover dam used steel pipes, not solid bars, so there's room for the corrosion to expand into the void created by the pipes.
Master craftsmen I tell ya, they think hard about that kind of stuff.
A flat roof, for example, is very prone to leaking, which when not constantly taken care of will wreck the building. Another is if the roof keeps water off of the walls (how big the overhang is). Many buildings have eaves that are an inch or two. The exterior walls of these buildings won't last.
Any building on a flat area near a river is going to flood. Any building without proper drainage around it is going to rot away.
Wood shingles need constant maintenance or goodbye to the building.
That claim seems to date to a particular article written in 2017 that wasn't well sourced. Roman concrete is interesting stuff and has useful properties, but humans have since created concrete mixtures that are far superior. But they're expensive, so it's not too surprising we don't see them getting used in buildings that compare less than favorably to a temple built a couple thousand years ago. Survivorship bias taken to the extreme.
Unless you’re talking about a very old house, this depends a lot on the local climate, construction materials, and design.
You can pretty successfully mitigate water entry with a dimple membrane and a gutter on an exposed wall, for example, and obviously this is a minimal concern if your house is in a desert.
(I’m not a trained architect, just someone interested in building science.)
My house has eaves that stick out about 2 feet. It added nothing significant to the cost, but boy what a difference it makes. The exterior walls almost never get wet. The windows and their frames stay dry and free of rot. No mildew. Haven't even needed to repaint.
There are a lot of things one can do with a house that, at trivial expense, will dramatically improve its life and lower maintenance costs.
Here's another one. Run the plumbing up interior walls. Then it won't freeze.
If you have a two-storey house in a wet area that gets a lot of storm activity coming from the northeast, for example, and you have an exposed northeast-facing wall, the eaves aren't going to do much to shield that wall from driving rain. You'd have to make sure it's dealt with in other ways.
> Here's another one. Run the plumbing up interior walls. Then it won't freeze.
Same with this - it might be good advice in Seattle, but if I told a local builder to worry about frost mitigation where I live now (Singapore) they'd probably question my sanity.
Texas felt the same way until February!
Modern concretes can do a whole lot of stuff Roman concrete can't, because there are so many formulations of it. But if you want to stick a building literally in the ocean and have it never ever disappear, nobody has shown that we can actually do it today.
There's a whole lot of theory and talk by experts, about how we don't need to make it, but if we wanted to, boy would it be easy, but don't worry, modern concrete is just so amazing, you should just use that, for modern use cases, and oh by the way, it would be too expensive to make, even though we haven't actually made it or tried to bring the price down.
There's a world of practical experience needed to claim for a fact that modern concrete is legitimately better, much less that we can actually make it and that it would hold up as we expect. I'm still waiting for concrete evidence.
And I have a friend who lives in Texas. The pipes in the outer walls froze and burst, the ones in the inner walls did not.
Jeez, of course one pays attention to the local climate. I don't worry about tornadoes in Seattle, but would if in the midwest.
Believe it or not, this kind of thing isn't just immediately obvious to everyone.
The bigger difference in components is the kind of cement the Romans (and we "moderns" until a few years ago) used, i.e. pozzolanic cement, nowadays everything is "portland" cement.
BUT the definite difference is the kind of structures, Romans did not use "reinforced" concrete, only various types of "plain, non-reinforced" concrete, and all their structures are based on the main characteristic of concrete, which is its resistance to compression.
The idea of reinforced concrete is all about adding to a material with excellent compression resistance (but no resistance on tension/traction) a material (steel) with excellent resistance to tension/traction and relatively poor (in the quantities used in reinforced concrete) resistance to compression, obtainining a composite material that excels in both.
About ashes, overall it is more about their size that about their nature, concrete is a composite and if you have all possible sizes of aggregates (ashes are very, very small sized particles) in the "right" amount you essentially fit "better" the space, i.e. you have a higher density of the resulting composite, and, particularly when compression resistance is the goal, the higher the density the better the resistance.
Imagine (say) that you have to fill a 100x100x100 mm box with 10 mm balls, you can fit in them a certain amount of these balls (roughly 10x10x10=1000), but you are leaving lots of "air" between them, a single 10 mm ball is 2/3x3.1416x5^3=262 mm3, so the 1000 balls total 262,000, but the volume of the box is 100x100x100= 1,000,000, now if you have some 2 mm balls you can add them in the same volume, and then if you have some 0.5 mm balls you can put some of them in that same box as well, etc.