It usually takes a few seconds or minutes because they are made in factories.
how long does it take to build a asimo
how long did it take to build the half moon
how long did it take to build the scottish parliment?
how long did it take to build cabot tower
A while.
3 seconds
hs2 will take 15 years to build
how long does it take to build a beam bridge of 2400 sq ft
About as long as a computer, maybe an hour.
How long did it take to build st James cathedral london
it took 3 years
3 hours