Unless you’re talking about a very old house, this depends a lot on the local climate, construction materials, and design.
You can pretty successfully mitigate water entry with a dimple membrane and a gutter on an exposed wall, for example, and obviously this is a minimal concern if your house is in a desert.
(I’m not a trained architect, just someone interested in building science.)
My house has eaves that stick out about 2 feet. It added nothing significant to the cost, but boy what a difference it makes. The exterior walls almost never get wet. The windows and their frames stay dry and free of rot. No mildew. Haven't even needed to repaint.
There are a lot of things one can do with a house that, at trivial expense, will dramatically improve its life and lower maintenance costs.
Here's another one. Run the plumbing up interior walls. Then it won't freeze.
If you have a two-storey house in a wet area that gets a lot of storm activity coming from the northeast, for example, and you have an exposed northeast-facing wall, the eaves aren't going to do much to shield that wall from driving rain. You'd have to make sure it's dealt with in other ways.
> Here's another one. Run the plumbing up interior walls. Then it won't freeze.
Same with this - it might be good advice in Seattle, but if I told a local builder to worry about frost mitigation where I live now (Singapore) they'd probably question my sanity.
Texas felt the same way until February!
And I have a friend who lives in Texas. The pipes in the outer walls froze and burst, the ones in the inner walls did not.
Jeez, of course one pays attention to the local climate. I don't worry about tornadoes in Seattle, but would if in the midwest.
Believe it or not, this kind of thing isn't just immediately obvious to everyone.