Here, we see the drain for the washer, the utility sink, and a very shiny new outlet that is not yet connected - wired, but not hot yet.
With the drain, I got lucky. When they built the carriage house in or around 1901 (really! It shows up on the insurance company's map for 1901!) it was all the rage to include an outhouse for the gardener, apparently. At any rate, on the other side of this wall is what's left of a urinal, and on this side of the wall, I have a convenient Y for my washer and utility sink drains. (Otherwise I wouldn't have considered putting them here.)
The only problem is that the existing fittings, being iron, are impossible to move. I even got a bigger pipe wrench and jumped on it - the only thing that happened is that the entire drain stack moved, but not the fitting. Rather than snap things off the drain stack, I tried Plan B - turns out the insert of a 1-1/2" drain trap fits into that fitting pretty well. So my drains are 1-1/2" PVC, and the insert sticks into the cast iron drain, and everything works out pretty well. Once it's all solidly installed, I'll caulk around the seal to keep the noxious fumes out.
Not too shabby for a day's work.