We used those "Organize it"cubes to build our bunny condos and with what we had left over we have used to build gates to block off rooms they arent allowed in. We just got a new couch and we have the same problem- sits 6in away from the wall. So we just attached two of the squares from the cube sets and put them there as a little gate. The rabbits cant climb it and neither have seemed very interested in jumping it. If they did then we would just build it a little taller.
You can buy these cube sets for $13 from Target and available other places by different names. Walmart has them as well but there are less squares and cost more.
Once I figure out how to post pictures on here i can show you what i mean.