If you stack them up how do people get in and out. Great idea if humans have wings.
ladders/stairs or even external elevators.
To be honest, this looks better than midcentury bay area houses 
This is quite a luxurious upgrade from cage beds.
This is the Kim solution to the SF housing problem…Put all builders, developers and lanlords in cages. And let the homeless take over the streets…
In some way the ppl in hk ask for it themsleves. Instead of 150sqft they counld have 250sqft for same price. But instead of living space. They want luxury lobby and club house. Lee ka shing already said we build what ppl want.
Also, 10 yrs ago Hk used gross area of construction（建築面積） and now used practical building area（實用面積）. So basically a 300 sqft now is around 380-430 sqft back then.
Young people have a choice to buy 20 yrs old flat 300 sqft 2 bed for 5 mil, instead they choose to buy brand new flat with luxury lobby and club house (resaturant, cafe, pool) @ 180sq ft. for the same price
Poor HK people. But not really… I think their “pigeon cages” are still worth a lot of money… 
USD 770K for less than 300ft nano condo in Hong Kong. Now that’s the world champion of RE.
has better stuff than 700sqft apartment here - a good chunk of apartments don’t have dryer/washer here 
I own a couple condos that are 650 sqft. So about twice the size…
I missed this thread when it first posted.
All I can say is that using a tube seems like a waste of space. It may stack a little shorter, but squares would be a more efficient use of space.