Underground housing, underground businesses, etc. Would that be better for the environment + possibly save on energy costs? Also possibly safer in certain scenarios like tornadoes etc.
Potential issues that immediately come to mind are ventilation, earthquakes, and flooding. But it’s not like underground dwellings/basements/etc. aren’t a thing, so maybe those issues have been addressed in ways I’m not familiar with.
In a number of places, it’d be great in a number of ways.
The big issue, as usual, is cost. Want a house? Fast growth wood frames can be built in a workshop/factory, stood up quickly, capped with more fast growth wood roof frames, skinned with thin boards made from woodchips and sawdust, or just chickenwire and cement, roofed with tar, and slathered in cheap acrylic paint. The engineering is all off-the-shelf at this point because it’s so common.
Want a U-house? You’re going to be digging. Digging down a foot or two isn’t that big of a problem but tends to get more difficult the deeper you go, so expect a lot of excavation costs compared to the stick-built house. Then you have to make all those walls strong enough to hold back the surrounding earth. Get ready to spend a lot more time doing engineering tests to make sure the retaining walls will hold, the water won’t turn it all to mush, etc. There is an earth pressure underground just like there’s water pressure in the ocean. Then there’s the roof. If it’s really underground, that’s a lot of weight to support. All that support has a material cost. All the engineering work to make sure it’s safe has a labor cost. Hiring workers who have the kind of training needed to do more than run a nail gun and a paint sprayer has a labor cost. The finding of those people at all can be a difficult task for the contractor/developer, and can be quite difficult when most house builders haven’t been doing that kind of construction.
And at the end of all this you have to get someone to pay for it. Getting people to pay even the same cost as the stick-built house for a house that doesn’t fit into their dreams of looking like the vision of success implanted in their brain by the pop culture of their youth is way harder than just cutting corners and being the Walmart of housing. Being a slacker sometimes pays incredibly well. Greatness can never succeed in capitalism because the one-size-fits-most model is always more profitable.