Your company will be more salable if procedures are clearly systematized and documented so that a competent manager or new owner can take over with minimal training. Get it out of your head and into a procedure manual. Make sure the procedures are tested and refined before the sale. It sometimes makes sense to own real estate as a company asset. But when it comes time to sell, including it as part of a business sale can increase the complexity of the sale and make a business less attractive.
Sophisticated buyers like to transact real estate separately from the business itself.
Also, if real estate is separate, you can start showing rental to the real estate owner as a regular line item expense for the company, making it more clear and acceptable for a buyer to assume the expense. Otherwise you might find yourself responsible for the new owner's liabilities or liabilities that he agreed to takeover. Make the change now because it takes time for creditors to change things over in their own records. Incorporating just before a sale to distance one's self from obligations is not foolproof. In fact, if you wait too long, you may have difficulty meeting IRS filing requirements and other bureaucratic requirements that are notorious for taking too long.