Annex (building)
![](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/ForsthausWaldhusenAnbau.jpg/220px-ForsthausWaldhusenAnbau.jpg)
An extension is understood to mean both a structural measure with the purpose of expanding the usable area of an already existing building and the result of this measure, the part of the building that has been created . In contrast to an extension , the horizontal expansion of the building is expanded by an extension, thus increasing the floor area. A building permit must be available for an extension and it must comply with the requirements of public building law .
An extension is directly connected to the existing building. In contrast to the term building wing , extensions are small extensions without their own architectural characterization. In Germany, extensions are found mainly in rural areas near older buildings. These were often built so that the house was built first. An extension, such as a laundry room, stable, etc. was carried out afterwards “when there was money again”. Former agricultural spaces in extensions, such as stables, are nowadays often used for other purposes due to their no longer existing original use, for example as a utility room to ban washing machines and dryers from the house or as a workshop or party room.