The typical farmhouse is a solitary building, often surrounded by fields of crops or livestock, and relatively far from major population centers. Some farms do have high fences built around the perimeter. Also farmhouses with a large open surrounding area can be a snipers dream location. A farmhouse can be secured with relative ease and often with a great deal of discretion (important if the people securing the building do not wish to attract other survivors).
A farmhouse, if properly constructed and secured, can be a viable alternative to venturing into a town or village hoping to find a secure building. For farmhouses near wooded areas or areas with rolling terrain, these areas provide their own unique advantages and disadvantages. Proceed with caution.