Using flash with HDR is becoming a very common technique. In this video real estate photographer Michael James demonstrates how he uses a Visual Echoes Better Beamer Flash Extender to light dark porch areas in exterior shots.
While Michael is demonstrating this technique with HDR, there's no reason this technique has to only be used with HDR. You could just as well use it with a single exposure. It all depends on if the dynamic range in the scene calls for HDR. This is just another technique for your tool kit. Many real estate photographers will handle this problem with placing remote triggered flashes on the porch or area that needs an extra bit of light.