My first thought on reading the OP is that Lego toy building blocks aren’t strong enough to be used to build houses, but after reading about them, I believe they are. A small (about 800 ft2
on 2 stories) such a house was actually built in 2009 - James May’s Lego house
For some neat inside views (it’s full of silly lego replacements of usual household things), see this page
In this Gizmodo article
gives a compression strength failure test for Lego blocks similar to common building materials such as concrete block, so it’s reasonable to conclude that anything you could build using ordinary masonry, you could build using Lego.
The reason there aren’t Lego houses (except for May’s little toy house, which was dismantled only a few weeks after it was completed, after plans to move it to permanent display in a LegoLand theme park were canceled, perhaps due to the cost of disassembly, transport and reassembly, estimated to be about US$100,000) is cost. May’s house, which was built for his “Toy Stories” educational TV show, was effectively zero cost, as the Legos were donated by the manufacturer, and its 7 weeks of labor was done by 1000 unpaid volunteers. Assuming a typical lowest cost for used Legos (about $11/kg), the materials for this little house would cost about $84,000, and at a very low $10/hr, the labor about $2,800,000. Though a factory to assemble the little Legos into larger, hollow blocks might reduce this labor cost a lot, I doubt it beat the cost of ordinary masonry and lumber construction. The ABS plastic Legos are made vary with its market, but is rarely less than $2/kg, so even if you had your own Lego factory that cost nothing to build and operate, the material cost wouldn’t be much reduces. In short, I can’t see that Lego houses could be made for much less than about 10 times the cost of ordinary ones.
Houses in hurricane season would simply be reassembled , and the concept of ownership would be devalued (people aren't going to care who's bricks are who's)
I doubt replacing concrete, wood, and other usual building materials with more expensive ABS plastic would change the economics of material ownership much. Lego’s being worth more than most materials, I expect it would at least slightly increase, not devalue, the “concept of ownership”.
Like most other plastics, ABS is made as a byproduct of hydrocarbon refining, so as oil, coal, and other hydrocarbon reserves become scarcer and more costly to extract, given constant demand, basic economics dictates its cost will increase. If demand increased (which would happen if we started building whole buildings out of it), its cost should increase
Having built more than I wish using salvaged materials, which involved a lot of “cleaning” work, mostly chisel/hammering concrete off of block and brick, and also built a lot of little things with Lego, which didn’t, I wish more stuff was made of Lego.
Other than at places like LegoLand and for shows like May’s, though, I doubt this’ll happen much.