We are build a room in the basement and the seam of the house runs about 7 inches next to the furnace. It is only one side and does not block the access panel.

Can you explain this in different terms "and the seam of the house "

You need to check the specs for that furnace and see what the clearance margins are from surface that will burn.

Still waiting to hear an answer to my question but more than specs, check you city building code for space required and types of wall material. Ome codes call for fire rated drywall on walls and ceiling, kind of crazy if you ask me but that's codes for you.