If the quality of material is in question

for the buildings....

 

This depends on how the material is mined.

How effective, and cost-effective it is.

 

If lasers can work (*for mining), that would be a game-changer.

As much of it can be automated.

 

And further, giant CNC machines reduces time to

build, labour that is required as well.

 

So... Not necessarily using sub-grade soil

as material (though it will be combined

in a press to make it stronger) is the negative.

 

The lesser graded low-rise buildings can

be located to accomodate people in certain

districts, where they 'start out'. And

given by the government at very affordable,

or free. Given that it is structurally safe.

 

Earthquake is a factor, but it depends on

way it is designed along with the material

to support it (metal) from the inside,

and cement.

 

But other than those districts, subtractive

method of building with metal, skyscrapers or

something more important will be even stronger

than traditional designs as the structure

uses more metal.

 

That may go same with the low-rises as well,

if primarily, the base is metal, than it is

soil, then soil can be used to cover rest of

the volume.

 

But. I think the overall idea in cost-effectiveness

is the factor of time and labour. The process

will be nearly automated. And it depends on

what the country holds as natural resource,

ownership thereof....

 

So it will still be very much cost-effective,

as compared to traditional type of buildings....

 

That is my guess.