How would a granite building fare in a direct hit from a tornado?

If you’re in the direct path of a major tornado I don’t think it matters. Some of the destroyed buildings in Joplin were brick and that didn’t make much difference.

@Adirondackwannabe yes, but isn’t granite a lot stronger than brick?

@Aster Yes, but you’ve still got the joints to worry about.

Tornadoes would probably do just about naught to a granite building (then again depends on the strength of the tornado and the structure). Chuck Norris, however, is a different story all together.

In the case of brick buildings that collapsed (or granite buildings that would collapse) under such an onslaught, @Adirondackwannabe is on the right track: it’s the joints that matter. That, and the sizes and weight of the individual blocks / bricks, and…
the footings, and whether any of them are affected by wind, rain or flood
the full weight of the structure
the geometry of the structure
the overall design, and whether the brick / stone is self-supporting or is just a facade for wood-frame structure

“A castle” would probably survive any known windstorm. That’s why they have survived a thousand years’ worth of all kinds of weather, in some cases. A wood frame building with granite facing would probably survive no better than any similarly-configured building with roughly similar siding.

Location, of course, is kind of a wild card. Identical structures side by side can have completely different results from a tornado, depending on the fickleness of the wind. It would be impossible to say “this building survived because of ‘x’” in every case, when tornado results are so wildly unpredictable, from storm to storm and even from one block to another in the same storm.

Windstorms don’t do noticeable damage to “stone”. So if you can develop a stone-like surface (or use stone, obviously) and cement it together well enough so that the joints appear to the wind the same as the stone itself, and if the thing doesn’t topple, sink, deform because of bad design or blow away because the builder decided to use the least amount of stone possible, etc. then you might have something.

But it’d be a hell of a place to heat in the winter.

It is the supportive reinforcement that makes all the difference. The shorter the span….the better. If you look at what is left of anything left still standing you will see closets and bathrooms. Those sort spans tied together with supportive studding is many times stronger than the same studs spaced apart. Wood is very elastic compared to brick and is why you see these tiny rooms still there.

Also consider all the people who survived in stores and restaurants who took cover in the small back room areas….again there you have closer spaced supportive reinforcements.

It would take extraordinary reinforcement to build an F5 proof home but in the end that may not help as the stories of adults, kids and babies sucked up into the tornado from secure areas is stunning and very very sad.

Like @WasCy points out it can be pure luck to survive these things. I remember reading this first hand account of a guy out for a jog and he saw the sky darken turned around and saw this huge black wall right behind him. He ran into the woods and grabbed hold of this tree. His body was battered bloody by this F4 tornado and he had to endure the front wall and then the back wall of the tornado. When it was all over he saw he was holding on to the only tree left of an entire forest.