High-rise directive
The guidelines on the construction supervision of high-rise buildings ( high-rise guidelines - HHR ) define the construction supervision term high-rise in Germany and regulate the requirements that must be observed when building and maintaining a high-rise.
In Switzerland, the term high-rise is defined in the cantonal planning and building laws, aspects of fire protection are covered by the VKF fire protection directive.
definition
"High-rise buildings are buildings in which the floor of at least one lounge area is more than 22 meters 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 fire brigade's rescue equipment 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 additional problems and risks that do not occur with low houses. Examples are:
- The attack 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 .
- The transport of extinguishing water becomes more difficult and at some point even impossible with the resources of the fire brigade (hose material and pump outlet pressure are limited). Dry and / or wet risers are therefore required for high-rise buildings , sometimes with booster pumps.
- Fighting fires in high-rise buildings presents the fire brigade with particular difficulties, so the spread of fires should be particularly prevented. The high-rise guidelines contain regulations on the subject that go beyond the normal regulations (e.g. laying of cables (pipes, electrics, telecommunications), requirements for the building materials, etc.)
- 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.
- The higher number of users (based on the area) increases the risk. Fire extinguishing systems , fire alarm systems or hand-held fire extinguishers are therefore required from certain building heights .
In contrast to the building regulations , the high-rise guidelines also contain operating regulations.
The high-rise guidelines can be designed differently in detail in the individual federal states . Some federal states have introduced the model high-rise building guideline (MHHR) directly from the building authorities. In other countries there is no corresponding legal regulation, here the validity of the model guideline is specified in the building permit or each individual requirement is listed as an ancillary provision. Hesse introduced its own high-rise guideline on January 1, 2014, which differs from the MHHR in some details. In North Rhine-Westphalia, the MHHR has not remained unchanged either, but has been incorporated into the SBauVO in an edited form with some simplifications.
