I generally like the comments posted here by DoreenMichelle. I would cite the historic cobblestone or quarried Belgian Block pavements in American port cities like Philadelphia and Savannah as examples of locally available materials that were not local materials (many arrived as ballasts unloaded from the hulls of ships that were departing town heavier and more stable than they had arrived) but economic afterthoughts. Is it still a vernacular practice of local knowledge and local conditions that prevail in the built environment, if instead the citizens had simply used them as earthfill rubble to create new land out of wetlands? I would say no; practices that have left a trace only in being cheaper than other methods of earthfill don't meet my criteria for a vernacular practice, although they may have still been performed by some of the same families who would be continuing to pass down that pattern of form in that same tradition.
On the other hand, if forestry and agriculture oriented areas of the USA find their local furniture and textile manufacturing tooling falling out of demand as furniture production goes offshore, is it possible to call it local knowhow if they repurpose those manufacturing plants to produce wood-framed, furnished turnkey mobile home trailers? It is still vernacular practice but at one remove, its nature changed by one layer (at least) of abstraction from a vernacular /tradition/, and its patterns denatured by that change as much as they were denatured by mass financing of managed mass production.
Taking advantage of local materials and resources, meaning that they are relatively energy efficient and sustainable.
Providing a vital connection between humans and the environment in which they live.
They can be designed specifically with the local climatic conditions in mind, and often perform well.
Vernacular architecture is associated with regional styles using local materials to build homes for ordinary people. Trailers are not any of the above.
I disagree with Hubka’s rejection of the McMansion as a topic of vernacular study, but I agree that it is not quite vernacular, either. However, I think there are some things about the McMansion that can only be understood through a more vernacular framework, such as their ubiquity and the means by which they are built. McMansions are not usually designed by architects but by builders, most of them massive corporations like Toll Brothers, Pulte Homes, and Ryan Homes that traffic exclusively in master-planned tract communities. Like most vernacular architecture, the McMansion might best be considered a typology—an architectural configuration that adapts over time but remains generally stable.
If you kidnap an architect and force them to design a building and keep adding requirements like people do to the builders, you'll end up with something very McMansion-like.
A good architect will try to convince you that what you say you want is not actually what you want, but they'll eventually quit or acquiesce.
(Some of the best "super large houses" are the ones that have other design limitations, such as some of the log homes you see.)
This is not remotely what vernacular architecture means. (And trailer parks are not vernacular architecture.)
https://www.designingbuildings.co.uk/wiki/Vernacular_archite...