Yes, I did extend the base. Sorry, I don't remember the exact measurement. Seven inches keeps coming to mind but I'm not sure and I no longer have the motorhome. I pulled the carpet and put half inch plywood down, reinforced the overhang with ribs, reinstalled the skirt and the carpet. I used the power recliners and installed a new power outlet box for them. This was the best upgrade we did to the Jayco. The only downside is the seating position ends up being elevated enough that your feet will not reach the floor when you are seated. Good luck with your project.