Various lenders handle the appraisal of acreages differently so be sure to understand how your chosen lender determines what they will lend on. Even the major lenders ie. the big 5 have widely varied instructions to appraisers about limitations on what they may consider to provide value, and some may offer different products that have varied levels of acreage and outbuildings they may allow to be included. Some lenders will allow the full acreage and include all outbuildings considered as residential use, excluding commercial use buildings or structures, and most often the maximum acreage is 160 acres.
Some will limit to a set number of acres ranging from 5 to 15 the appraiser is to limit the value to and exclude all outbuildings other than an attached garage or if none attached a detached garage.
Unfortunately, in some cases this can be a very large difference in value and if the borrower is not aware or does not fully understand these limitations it can come as an unpleasant surprise and in the case of a purchase may cause a sale to collapse.