Location, location, location. Farms for sale & office buildings can both be used for business. It is a common but important factor that must be considered, since it is driven home so often just shows how important location is when choosing a space for your office.
If your office fits both these criteria great. If not you must consider that how the inconvenience will affect your business. Many businesses often over look at the convenience for employees. If they are unhappy you will also have a loss in service level and may lose out on the best workers.
You will also need to consider security, parking, other businesses located near you, and common sense issues that are specific to your rental space.
Many offices in Iowa are acutally in rural settings. Farmland has fewer roads and less maintenance than major city streets and highways. Also most close house will be farm houses for sale, not making it easy for workers to find close by housing.
Many major sites have listings for both residential and commercial property currently available. A quick google search will yield many places to start looking for Iowa or Midwest real estate.
What about the landscaping and general lawn care. Do your customers get greeted by a nice, clean lot and well kept outdoor area? Employees will also enjoy a a well kept area for breaks during nice days.