When you build or install a fence, you need to consider a couple of things regarding your neighbours. You need to place the fence so it doesn't impede on property that legally belongs to another person. Also consider which direction the fence posts should face. While you might believe your fence will look better from your point of view if the posts go on your neighbour's side of the fence, this may not always be the best, or legal, thing to do.
Whether or not you need to consider what side to use for fence posts depends on the design for the fence you plan to install. Some fence types such as basket woven or shadowboxed fences incorporate the posts into the design, making it unnecessary to worry about the location of the posts. Other designs such as privacy fences or picket fences leave the posts exposed and create a necessity to plan ahead.
When you have a doubt as to where to place the structural supports, such as posts, for your fence, contact the zoning administrator for your area. Some zoning ordinance departments provide written regulations that clarify the legal placement for your fence posts. The regulations may specify the placement of posts based on the zoning of adjoining land, for example, residential, industrial or agricultural. Other cities and towns have fence regulations stating the finished side needs to face adjacent property or public areas, which means the posts should face your house. Regulations vary by county, town and state, so make sure you check with your specific department.
Aside from the local zoning department, you may need to check with your homeowner's association. Some associations have rules and regulations that comply with local codes but vary in minor details. While the city or town may allow you to put fence posts facing your neighbour's home, the association might expressly prohibit it.
Another resource you can use is the local code enforcement inspector. Contact this individual and ask for information regarding the location and position for fence posts. If you town doesn't have a local code enforcement inspector, talk with a person in the building permit department.
If you are replacing a fence, it's generally common courtesy to keep the posts in the previous location. In some places, people consider it courteous behaviour to face the finished side of the fence toward your neighbours' homes or toward the sidewalk.