A facade is generally one exterior side of a building, usually, but not always, the front. The word comes from the French language, literally meaning "frontage" or "face". In architecture, the facade of a building is often the most important aspect from a design standpoint, as it sets the tone for the rest of the building. From the engineering perspective of a building, the facade is also of great importance due to its impact on energy efficiency. Many facades are historical, and local zoning regulations or other laws greatly restrict or even forbid their alteration.