A building setback or building setback line on a survey, site plan or plat in regards to land development is the distance the building is setback from a street, alley, property line or road. Building setbacks are set up by land developers and local Planning and Zoning Offices and are different for every subdivision. If you take notice of a typical neighborhood, all the houses line up (for the most part) in the front. This is because of the building setback line. Building setback lines exist for many reasons. They prevent building structures from being built too close to one another, prevent fire from spreading to buildings or home that are too close together, and serve as utility easements for local power or water companies to gain access to properties where they have their meters. Older neighborhood typically have shorter building setbacks because walking was the primary means of getting from place to place and as result, local governments wanted to keeps distances shorter.
If you are planning a room addition or building any kind of accessory structure to your home, I would definatly check with your local Planning and Zoning Offices before you begin construction. Building setbacks can also be located on your survey that should have been provided when you purchased your home.”–Danny Garcia, owner of Rhino Design Build in San Antonio, Texas.
Depending on where you live in the country, enforcement of building setbacks is taken very seriously. The local government can make you tear down the structure and fine you if you have built something that encroaches the building setback line or easement. A land surveyor, civil engineer or qualified building professional can determine where your building setbacks are and even mark them with flags. It is wise to discuss where all easements and building setback lines are on your property with your building before starting and kind of home renovation or home remodeling. Some Home Owners Associations have height restrictions for any new accessory structures.