Duplex
The term double house stands for different, sometimes overlapping terms in the building industry .
Residential building architecture
In residential building architecture, Doppelhaus refers to two single- family houses built next to one another and often uniformly designed . In Austria , the term coupled construction is also used for this.
As a rule, one speaks of a semi-detached house if two houses (“ semi-detached houses ”) are built next to each other on the property line; However, one or more semi-detached houses are also possible on an unseparated property (e.g. in the legal form of apartment and partial ownership ). The decisive factor for the design is that there are two separate buildings that are continuously separated by a fire barrier (formerly a common fire wall , now two walls with an insulated separating joint). The two halves are often designed similarly, often with an axially symmetrical facade design and floor plan. A typical semi-detached house thus resembles two mirror-symmetrical detached houses.
Usually the common wall is a side wall of the buildings. If it is the back wall, it is called back-to-back development. If no symmetrical construction can be seen in the two halves, one speaks of "attached on one side". If more than two buildings meet with their side walls, the building complex is called a group of houses . The advantages of this type of construction compared to free-standing buildings are a more favorable use of space on the property and a reduction in heating costs due to a lower proportion of external walls. Disadvantages are that each wall has to remain windowless and the limited sound separation between the two halves of the house.
Historic manor architecture
The double house (also double roof house ) is a variant of the so-called multiple house in the historical manor architecture in Schleswig-Holstein . Here, the building consists of two rectangular houses joined together, the gable roofs of which run parallel, giving the house its characteristic silhouette with two adjacent gables .
Building law
In German building law, a semi-detached house in accordance with Section 22 of the Building Utilization Ordinance (BauNVO) refers to a building construction with two houses built next to one another on one side at the property boundary. The position to the property boundary is decisive. Semi-detached houses on non-separated plots are considered to be single houses under building law. The number of apartments or house entrances is irrelevant. In this way, multi-family houses or office buildings can also form a duplex in terms of building regulations. Other building types of the open construction according to § 22 BauNVO are the single house and the house group .
