Your company will be more salable if procedures are clearly systematized and documented so that a competent manager 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. If you are operating as a sole proprietorship or a partnership now may be a good time to incorporate for two reasons. First, it is better to have the corporation liable for payables and other debts. Otherwise you might find yourself responsible for the new owner's liabilities or liabilities that he agreed to take over. Make the change now because it takes time for creditors to change things over in their own records.