A reader recently told me, "I know you don’t think the 14mm (full frame) lens is suitable for RE work, but I have found that to be quite the opposite! I have the Nikkor 14-24mm f/2.8 lens (the finest lens I have ever owned hands down for RE work!!) & I use it @ 14mm 75% of the time. I just crop as necessary to get what I want. You really ought to reconsider your opinion on a 14mm lens as not suitable for RE work".
First of all I want to clarify that I agree with this reader. The Nikon 14-24mm f/2.8 is one of the finest ultra-wide angle lenses on the planet! And it's not that a full frame 14mm isn't suitable for real estate it's that when shooting below 24mm you get more perspective distortion. Some visually sophisticated viewers of your work will notice perspective distortion and other less visually sophisticated viewers won't.
What I mean by perspective distortion is the shape of the pot in the little potted tree in the bottom left corner. We all know that this pot has a round top but round objects in the corners of photos shot with a wide angle zoom at 16mm like this shot will appear oval. Rectangular tables won't look rectangular and floors sometimes take on some strange looking slopes. All objects in the corners have this wacky look but the only ones viewers notice are the objects that they have expectations about. It's like converging verticals, we know walls are vertical and when they don't look like we expect we notice.
When I got my first full frame camera body and a 16-35mm zoom I was just like the reader that uses his 14mm all the time. I was in LOVE with 16mm! I swear I didn't take the lens off 16mm for a year! During this period, I had potential buyers that accused me of trying to deceive them by making rooms look bigger than they were. I had one of our listing customers characterize photos with perspective distortion as having a "cartoony look" and my wife would complain that some rooms in our listings looked like they were "bowling alleys" and send me back to reshoot.
What I pointed out to the reader in love with 14mm, is that you can get away with this visual "foolishness" when shooting for some real estate agents because they are that visually sophisticated. But you won't get away with it if you shoot for an architect, designer or even an agent that subscribes to Architectural Digest! Ever notice that you don't see 14mm and 16mm interior shots in Architectural Digest? It's because AD's target audience is a visually sophisticated.
So, I'm not saying, "don't use your wide angle at 14mm". I'm saying use it with restraint. Use it at 14mm in those funky little powder rooms or small rooms. Try to stay close to 24mm unless going wider is essential and when you shoot wide pay attention to objects in the corners of the photo and try to minimize those long straight bowling alley lines.