Hi! Before we know whether this a territory issue or an emotional issue, you need to be sure that your cat is healthy and not ill. If all his habits are "normal" as they have been in the past, then is is possible he has an issue about territory. Normally this is done with marking, but I have had friends who have had male cats do this at different times. One was when she she got married. My other friend, it was because of a new kitten, the older cat refused to use the litter box the kitten had used.
Suggestion, you didn't say if you have a littter box inside. If you do not, get one and make sure the cat knows where it is. Second, keep it clean and fresh. If this is a terrory issue, I have used a produce called "Feliway". Because I usually am fostering up to three litters a year, my one male sometimes gets upset and I have to use this to get him to not pee around the kittens or on my bed!!! This works great, it is available from your Vet and some very high quality pet stores do carry it now, and it is creaper there. The other possibility is that he feels threatened by the visitors for some reason he can not tell you.   Try to analyse and thing new or diffferent that happened a few days or a week before this began. There is also a VERY remote possiblity, and I mean remote,also you mentioned custom couches. Are they new? What are they made from and what is the stuffing? If they were older couches and you had them redone, some were stuffed with horse hair. Like a said, this is very remote, but I am trying to think of any and ALL possibilities. That could also be a factor. I hope I have helped you!!

Contach if you have more questions, if I have helped you..Please click the "accept" butons so the top guys know I have helped you.