In 2000 years they will still be finding Roman Ruins but nothing from the 20 + century will survive.
For a while we lived in an upper-middle-class house (at the time it was built) constructed around the time of WWI. National historic registry, the whole thing, but little reno or updating. The hardwood floors were intact but in terrible shape. Siding probably needed to be replaced. No air conditioning (Iowa, so summers hot enough for at least a month or so that you really want AC) inadequate gas heating, no insulation, etc. Point being that, even when occupied, the house experienced swings between ~55f in the winter and ~100f in the summer.
The remarkable thing? It had incredible woodwork, just... everywhere. Bannisters, fireplaces, big wooden pillars with accompanying massive trim between rooms, everywhere. The doors were all custom built, paneled, and solid wood—they'd be considered top-end luxury today. It'd cost a fortune in material to do that now, the lumber was so good, but the really crazy part? The intricate joins and such were so tight you couldn't fit a piece of paper between them. I mean perfect, despite ~100 years of temperature swings like that. Good freakin' luck finding anyone who can do that today, and if you manage it, good luck finding enough money to pay them to custom-trim an entire house that way. It'd be off-the-charts expensive.
A corollary to the labour cost also seems to be a reduction in high end craft skills. Modern houses don't have the features that require high end skills as they're too expensive so there's less demand for those skills. Another anecdote: it took us ages to find a plasterer who could do the ceiling in one of the bedrooms as the cornering was so complex and most refused to quote. Eventually, one of them put us in contact with a retired gentleman who did the work (at a quite reasonable price considering). Watching him work was amazing.
The only time I recall being more impressed was, many years ago, seeing a spray painter paint a propeller as a template for the robot. It was a bit like watching dancing but to a micron (or so) tolerance. Masterful.
The problem was that the software for defining the arcs that the paint gun needed to move through was, well, a bit shit. It always produced inconsistent thicknesses.
Obviously, prior to getting the arm, the props were painted by hand. There was this one chap who was just incredible. He'd move his arm in a motion that followed the contours of the prop perfectly but at such a consistent pace that the paint was laid down beautifully. In the end they gave up with the software and just motion captured his arm movements so they could replicate it. It wasn't as good as he was but was close enough.
BTW my job there was to design jigs for a batch of Spitfire blades that they were building. Someone had commissioned new 'planes to go with some Merlins that had been found at Rolls (if I recall correctly). I worked at Dowty who had made the original blades and landing gear so we were making them from the original blueprints. Was a lot of fun.
Ironically, she was supposedly built to only last 25 years. That might be just an urban legend tho.
[1] https://www.newbedfordguide.com/charles-w-morgan-whaling-shi...
Story is that once upon a time you could sail a ship into Mariahamn in Åland and be able to hire someone for any position from cabin boy to captain. You can't now - those skills are much more diffuse.
Same thing with steam engines. Used to be you could find a boilermaker locally, because the demand was so high. Or farriers, or wheelwrights, or any of a large number of skills related to horse transport.
Even things like home milk delivery and cloth diaper services are harder to get now than in the 1950s, because improvements in pasteurization and disposable diapers have changed the economics.
If you want a new boiler, or want to hire a sailmaker for canvas, or decide you want to keep your own horse&carriage, you'll find it's harder to do so it now than 100 years ago. Not because we've "sorta lost" those skills but because the support infrastructure has dwindled.
For example, the ship the Götheborg is a replica of an 18th-century Swedish East Indiaman. It uses linen sails instead of hemp, as the original would have, because 1) growing hemp was banned in Sweden in the 1970s, and 2) the Hungarian weaving company they were going to use for the hemp sails went out of business in 2000. The linen sails, btw, were made in the UK.
Of course, 200 years ago it would have been much easier to order hemp sails for an East Indiaman.
I'm not sure that's great evidence.
Working with a historical artifact means you have to be more careful - it's more museum curation than construction. It's also generally slower to take something apart and rebuild it than to just put it together the first time.
In my mind I (rightly or not?) consider that in a different category altogether.
As software engineers we are blessed with the opportunity for depth in craft much more than most workers nowadays, but we still live a fairly nerveless existence, with the tips of our fingers being just about our only meager contact with the world while the rest of our body atrophies.
I've started learning woodworking with old hand tools, but so far it's just made me appreciate more just how skilled these old woodworkers were.
Often times buildings are disappointingly short lived, but I think sometimes people lament it a little too much. If we need a different building there 50 years later, and we built it to last 200 years, then a lot of material and effort was wasted. There's often a lot of good that comes from knocking a building down and using the limited space for something more useful.
Not as long as you would think. Non-reinforced concrete only lasts a few generations, whereas there are Roman concrete roads still in (mild, rural) use today.
We actually know why too. Recent science shows that Roman concrete used a slightly different formula that took much longer to set -- weeks or maybe months rather than days. They didn't know how to make fast-setting concrete like we have today. But the length of time also made the structure stronger. We could build that way, if we wanted. But we don't.
[1]http://www.sciencemag.org/news/2017/07/why-modern-mortar-cru...
These days, we're so crammed in where ever there are usable resources, that the moment we die, or move on, someone claims the space and adapts it to their needs. Space is at such a premium that it's illogical to lock it out as one particular usage for centuries.
Average Romans were probably slaves and, not sure, but probably lived in shanties that definitely don't exist.
The mosaics and stuff that survives today is likely the home of an elite, or some important Government building. So the right comparison would be to, say, Empire State Building.
https://en.wikipedia.org/wiki/Freedman
that - once freed - became a citizen (with some very marginal restrictions).
Just a few blocks away was a medieval church built hundreds of years later. The mosaics there looked so amateurish that they looked like they were done by children.
Japan has somewhat of an answer to this: every 20 years they tear down the Ise Grand Shrine and build it up again. This allows them to retain specialized construction techniques across generations.
Those tiles aren't surface level like ours are, each spot in the mosaic is more like a rod, and it goes down a couple inches.
There are some beautiful counter examples, like for example the Rome Pantheon, but this building, being converted as a church, as been correctly maintained most of the time up to now.
Long standing (and sometimes beautiful) structures are still up because of proper maintenance, they can endure some kind of neglect for a few decades, but not a lot more. Maintenance is the key. (an even bigger example that comes to my mind is Hagia Sophia, which, in spit of being in a seismic area and being quite tall, is still standing today after ~1500 years).
As for the ruins, given the proper conditions, even your shitty bathroom can be preserved. Maybe not yours specifically, but one of the millions others like yours. Keep in mind that the Roman Empire spanned across most of southern Europe, the middle east and North Africa, that multiplies the "proper conditions" opportunities.
Several nuclear waste containment structures are planned with that kind of lifetime. They have to be.