Real Estate Wide Angle Autofocus Camera Lenses

Shown above is the Tokina AT-X 116 PRO DX 11-16mm f/2.8 Lens.
This is the fastest 11mm wide-angle lens available for APS-C DSLR Cameras

I could have just said Wide angle lens. Generally, in the interior of normal homes the wider you'll want your lens field of view. I shoot small rooms with at 10mm with a 10-20mm Sigma lens which captures nearly the entire room when I set up in a corner or doorway. This can make a cramped room or even a closet look spacious, it turns a regular bed into a king-size mattress, or makes a living room look spacious. Keep the film plane vertical to avoid warping straight lines. There is some distortion with such a lens (objects in the corners are stretched), use a 10-20mm zoom and a 18-20mm for larger rooms. There are pitfalls to using wide angle for every shot. In doing so you might ignore interesting details: the unique character of some interiors can be found in smaller areas or objects, or even close-ups. And viewing a portfolio with 100% wide angle and no variety can become somewhat tiresome.

For exteriors you're going to need a lens you can use with a circular polarizer and a graduated neutral density filter