Are you saying that a building doesn't have straight sides? When I look at a building I see the sides as parallel to each other. Even if my eyes showed convergence, in reality we know that the sides are parallel. It's the job of a photographer to capture reality - or at least it's the architectural photographer's job.
Jonathan, what is reality? Are rails of a railway "parallel" or "converging"? They are parallel but, for a well-known law of nature, they appear to be converging. In reality they are (visually) converging and not parallel. Axonometry does not exist in nature, all that lives sees the world according to the laws of perspective.
Railways are not different from corridors, and corridors are not different from skyscrapers seen from below. If we had the habit of walking upward or if we could fly, it would seem to us as meaningless to try to make building sides "parallel" as it would seem absurd to try to make corridors walls "parallel". If swallows took pictures of buildings, they would never use PC lenses...
Do this experiment: put yourself in front of a convex corner of inside your house, at a distance of let's say 1,5 metres. Now tilt your head up and down with movements of around half a second each (in one second you will have gone from floor to ceiling to floor again). You will clearly see that your eyes record the vertical line between floor and ceiling as being curve (it will come "toward" you at its nearest point to your eyes).
Now, guess what: that line IS curve to your eyes and cannot be otherwise. You know, and I know, that from an "engineeristic" point of view that is a straight line. But from a visual point of view, that cannot be a straight line because where the line intersects the floor, and the ceiling, are points which are further than the nearest distance between you and the wall.
Now repeat it with any other element. Put yourself under a beam of your house. Look upward, and swing your head along the beam. See how curved the beam is? To your eyes, it is curved. Physically it is not. Visually it certainly is.
Now you might say: OK when I am near the corner, and look fast upward and backward, the effect is quite apparent but in my normal experience this effect is so small and my brain automatically makes me not to notice it.
Well, yes and no. I can be very easily aware that the sides of the inside of any builiding are NOT parallel when I look at anything. I can go round my house and be perfectly aware that my eyes look at it as if I were in, so to speak, a spheric environment. We all look at the world like a toad does, only with a less extreme perspective.
It is a difference of degree, not of nature.
IMO our problem is how to make a certain picture look "natural". If you take pictures of a tall building, looking up, parallel lines will not necessarily look "natural". If you repeat your experiment with outside buildings and if they are tall enough that the perspective is evident, you will clearly see that the buildings don't appear to have parallel lines at all if you go enough under them and look at them upward.
Up to a certain extent our brain "stretches" buildings sides, but this "mental" effect is always only partial and up to a certain extent our mind is at the same time always aware of the perspective surrounding us.
Cheers
Fabrizio