There's a large number of tiny houses (especially the kind on wheels) where there's not much of an overhang on the roof. That's probably for aerodynamic reasons for the towed variety, but it's also a thing on stationary ones (probably for style)

Overhangs are overlooked, but very important to protect the walls. The walls of a house are *not* meant to withstand direct water impact. That's the roof's job and it needs to have an over hang to do it properly

Ideally, at least 1 foot or more

There's an art project by Dave Sinaguglia called the "Modular Men's Library", a title that's a bit tongue-in-cheek, which ironically illustrates what a roof overhang on a tiny house should be like

The library itself is basically the same style I'm envisioning for my library (but with insulation, of course)

https://cargocollective.com/davesinaguglia/Modular-Men-s-Library

Something else I've seen is the prevalence of flat roofs on tiny houses

There's again nothing wrong with the roof itself, but it needs to be built correctly or you'll have a lot of leaking issues. It's also a burden to have flat roofs in heavy snow areas. Especially since walls on these are made of lumber, not steel

@cypnk I feel like all of this is reasons to not construct a tiny house as a house, but rather as a vehicle, if you’re designing it to be regularly moved around.

Although flat roofs are silly for aerodynamics too… but having a longitudinal roof ridge is even worse (because you have a taller roof without any aerodynamic benefits for it). A transverse roof peak about 1/4 to 1/3 of the way down the length (like about where the door is on the tiny home you posted) could give you significant aerodynamic benefits…