Is it HDR, is it multiple speedlights, or is it photo layering? Whatever the technique(s) used, the real estate photos at Attic Fire are beautiful. Do they represent the properties realistically? According to their site, they’ll post process whatever you ask: clone chairs, remove a vent, whatever to create the atmosphere you want your property to project.
A note over at Photography For Real Estate sheds more light on the technique used: “These are composite images made from multiple exposures. One of the major advantages to this technique is that it saves massive amounts of set up time while on location. Instead of setting up dozens of individual lights, one can use just a couple (or one) and light a different part of the scene with each exposure and then blend all the exposures together.”
[Photography For Real Estate]