Randy makes a great point:
I’ve been doing sky replacements on homes shot on days when the sky is just not exciting to look at or it was a real dreary day, and needs some big billowy clouds overhead. I recently have noticed photographers offering twilight conversions where daytime skies are being replaced with beautiful red sunsets. This makes the house look very attractive, but also misleading to some respect. I’ve seen images of some local homes shown with beautiful red skies with the sun setting over the backyard. They look wonderful, but the sun actually never rises or sets in that direction. A prospective buyer may think they are going to enjoy gorgeous evenings sitting on their deck watching the sun go down over their pool, but in fact they will never see it happen because the sun never sets there. Adding clouds is one thing, but adding fake sunset skies? I would want to make sure I have a 'proper sky' for the angle in which I take the shot. What are your thoughts and what are others doing?
Randy, you make a good point! Putting a sunset in the wrong direction in an exterior photo can misrepresent the property physically. The photo above is an example. It's a listing my wife and I sold in 2000. I went back to the property many times to get a shot that wasn't rainy. Since it was November in Seattle I never did get a good sky shot. Fortunately, at the time, I didn't know how to do sky replacement. This sky replacement was done several years after we sold the property. When I was learning how to replace skies. This shows the sun in the North which if used as a marketing photo would clearly be a misrepresentation of how the home is oriented!
One thing real estate photographers should be aware of is that real estate agents (everywhere) are legally required to not physically misrepresent a property. So photographers should have a discussion with clients before they change some physical feature of a property. There isn't total agreement about what should be Photoshopped and what should not. Here is a summary many discussions we've had here on PFRE on Photoshopping ethics over the years.