When deciding the proper height of a wood privacy fence, you need to be aware of local state and city codes and home association restrictions. In most cases, you do not need a permit to build a backyard fence that is 6 ft. or less or a frontyard fence that 4 ft. or less, but there are exceptions. For example, sometimes a fence needs to be shorter to not block your neighbors line of sight to the road. You should call your local permit office to double check. A fencing company will be able to ensure your new fence complies with construction codes.