This one was a little challenging to figure out. They where entering at the corner of the porch roof right above the solid stone wall. With a bore scope thru the entrance, I determined they were going at least 18" along the rock wall (as far as I could go with the bore scope). Homeowner was hoping they were in the wall, and the fact that there was a bunch of dead bees in the one window sill, I drilled a few holes from the outside and took a peak with bore scope and determined they weren't in the wall. With an infrared thermometer I found a spot on the floor that was 3 degrees warmer than the rest. I test hole proved right where they were when the drill came out with honey on it ;) I then cut a larger hole to see how far back it went and to find the floor joists.
Cutting the floor up was the worst of it. Once I could get the sections up, I just sucked them up with the bee vac, put the brood in cut-out frames and put them in the vac. Took them home and set the vac on the hive stand and the next morning just swapped out the bottom and top. Had less than a handful of dead bees and some sawdust on the bottom of the vac. By the next morning, they had repaired/attached the brood comb and the queen was laying.
No I didn't do the repair. The contractor was there when I was trying to determine where the bees where. It was his choice to go in thru the floor, he thought it would be easier than dealing with the sheet rock ceiling and perhaps lathe and plaster it was covering. Also, by going in through the floor, it was all isolated to on bedroom, where downstairs was just one big room. In hindsight it was good, because 3/4 of the nest was over the stone wall and wouldn't have been accessible from downstairs. He is suppose the be repairing the floor today so that the new tenants can move in on Wednesday.