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Comment by tzs | Hacker News Reader

> If I had an unlimited budget and was aiming for >1000 years I would pour the piles to bedrock with stainless rebar inside fly-ash concrete and top those pilings with plate connectors into which you could socket large wooden columns (perhaps 8x8) and build the structure with large wooden members connected with steel connectors and column caps, etc.

Are there any existing buildings constructed that way that have stood for >1000 years?

If not, my approach would be to copy an existing building that has stood for >1000 years in a region that has had several of the same kind of natural disasters that happen at the place I'm going to be building.

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York Minster in England is mostly 1000 years old. There are some nice stories about how it handled a serious fire in 1984 here, (starting about 18 minutes in) https://www.bbc.co.uk/sounds/play/m0007pws. eg, the 2000 year old Roman drainage system got used for the first time in 1000 years because lots of water got inside the building from the fire hoses.

When rebuilding it, they had to decide whether to remake it in the same way it was originally, or to use a modern approach. They decided to use oak beams again because of lack of evidence about what happens to steel structures after hundreds of years. But then they couldn't find any oak trees big enough.

When planning to rebuild Notre Dame de Paris, there was a proposal to use titanium beams instead of the flammable oak ones that caused the deflagration in the same place, but they opted to go the original route, which involved finding old oak trees across France to harvest.

There is a story about one of the Ivy League universities. IIRC, in one of the century-or-two old buildings, there was a need to replace some main interior beams in a roof. Among the staff, someone knew someone who remembered something about this. Turns out, there was a special grove of trees, still under control of the university, which had been planted to provide replacement beams -- after 150 years of growth.

An old story about people having thought for the long term.

I've heard that as a story about Westminster, which makes me suspect the whole thing is an urban legend...

Actually 400 years - https://www.atlasobscura.com/places/oak-beams-new-college-ox...

I would certainly use wood, and then just design it like the Japanese do for their old buildings, which are continuously repaired and after 1000 years you would still have the same home but it would be a Ship of Theseus type of situation. Wood has been used for building for thousands of years, and I wood imagine that humanity will forever be using wood for building, so there is a small chance you would lose the knowledge of how to build with it.

Unfortunately German only: https://www.rheingau.de/sehenswertes/sehenswuerdigkeiten/gra...

The oldest stone house of germany, ca. 1k years old. The wood is dated to 1035..1075 ad.

But Im sure that house is pretty young for Italian or Egyptian standards…

Could be prone to some survivorship bias.

Sure, but what's the alternative?

Dig out all other buildings that failed over the last 1000 years, figure out how they failed and why, and take action?

You can just copy what is known to work instead.

Or like, look at any of the million dilapidated houses and realize that 1. most houses leak at some point and 2. termites eat wood. Then conclude that actually, maybe .0001% of wood houses lasting for 1000 years is not actually good evidence that wood is a material that easily lasts 1000 years. Then think twice about using wood.

Personally I'd a concrete dome: https://en.wikipedia.org/wiki/Pantheon,_Rome

The claim here is that one would look at _ALL_ 1000+ year ld buildings, and then decide what to build.

You are building the strawman of looking at _ONE_ 1000+ year old building, and then building that because it must work. Nobody is arguing about this, and probably everybody here would agree that doing this is a bad idea.

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With that out of the way, there aren't many 1000+ year old buildings made out of wood. There are some, e.g., japanese temples, that IIRC have burned a couple of times along the way, but are 1000+ year old and build out of wood.

But most buildings in the 1000+ year old range are made out of stone and only partially out of wood (cathedrals, etc.).

Concrete with basalt rebar. It doesn't rust like steel.

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