Some last for hundred years.Example is in Mali in West Africa.
About 2 weeks.
Prefab, kit, or offsite built homes are made to the same standards as any other home. You can specify what materials you want, whether it be iron roof and fibro cladding or brick and tile. All plans...
As long as the agency imposing the tax chooses to make it last and has the authority to impose such a tax.
About a year and a half--They are just made very cheap these days