When a contractor or homeowner decides to either build an addition to a home or undergo substantial construction of a structure, building permits will be required by law. Building permits are instituted and issued by local municipalities. In large cities or metropolitan areas, it is not uncommon for an entire agency to be dedicated to issuing building permits and deal with related issues.
Obtaining building permits and the involved process will vary by region and jurisdiction. A contractor will usually be well aware of the necessary agencies to call, though local homeowners may not be as well informed. Contacting the local city hall or courthouse may be the best way to obtain information as to how and where to obtain building permits for a particular location or region.
There will be building permit applications involved, as well as providing for plans, blueprints, and related documents in order for the local agency to assess that the proposed project or structure will meet imposed building requirements and safety codes.