The high-rise guidelines (in German: Hochhausrichtlinien, also known as “HHR”) define the term high-rise in Germany from the perspective of building supervision and regulate the requirements that should be observed when building and maintaining a high-rise. The high-rise guidelines can be designed differently in detail in the individual German federal states. The high-rise guidelines of the federal states are based on the model high-rise guidelines (M-HHR), which are adopted by the conference of building ministers. The general definition of the skyscraper in Germany is therefore uniform:
“High-rise buildings are buildings in which the floor of at least one lounge is more than 22 meters [72 feet] above the specified surface area.”
The justification for this definition is based on the fundamental requirement for two independent escape routes for each lounge and the principle that the second escape route may lead via the rescue equipment of the fire brigade. The largest rescue device standardized in Germany is a turntable ladder (DLK 23/12) with a nominal rescue height of 23 meters (the height of the parapet must be added to the height of the floor in order to arrive at the required rescue height). The rescue equipment of the fire brigade is therefore ruled out for the second escape route, which is why special measures are necessary (second structural escape route, safety stairwell, etc.).
As the height of a building increases, there are other problems and risks that do not occur with low houses:
- The rescue routes for the fire brigade are getting longer and longer until a point is reached at which the success of the extinguishing is questionable (an emergency worker who only has to overcome 50 meters in altitude with equipment of 20 to 30 kilograms does not have the power reserves for the extinguishing attack). For this reason, a fire brigade elevator is generally required from a height of 30 meters (98 feet).
- The transport of extinguishing water becomes more difficult and at some point even impossible with the resources of the fire service (hose material and pump outlet pressure are limited). Dry and / or wet risers are therefore required for high-rise buildings, sometimes with booster pumps.
- In large buildings, it is becoming increasingly unlikely that all residents will notice a fire and the associated fire service. For this reason, warning devices (e.g. an electrical loudspeaker system) may be required.
- Fighting fires in high-rise buildings poses particular difficulties for the fire brigade, so the spread of fires should be particularly prevented. The high-rise directives contain regulations on the subject that go beyond the normal regulations, such as laying pipelines, electrical lines, telecommunications lines, requirements for building materials, etc.
- The higher number of users (based on the floor space) increases the risk. From certain building heights, fire extinguishing systems, fire alarm systems or hand fire extinguishers are therefore required.
In contrast to the building regulations, the high-rise guidelines also contain operating regulations.