2013/10/8 fly <lowfligh...@googlemail.com> > > I know buildings on steep areas which have two different ground levels > so simply building height is really difficult. >
this is actually common, you will very often have different levels around a building, also in more or less even terrain. The solution for architects is to define a zero-level, sometimes you'd use the level of the road (a given measurement point with known height level) from where the main entrance is and other entrances will be on +1 or -1 floor (or even more). According to German law it is the "natural ground" to take into account (if you're in a built-up area it will already be defined what is the ground-level). This level will be defined in the site plan, and all other plans usually refer to this level, generally by using the (planned) finished floor level of the ground level as 0.00 for reference in the planning set (and with absolute reference for this level in the national height system). The ground level might often be defined by the local authorities in order to avoid cheating about the maximum ammissible height or number of overground floors. This is a really import setting for building a structure, as it will very often define how high you can build, so there will often be an official definition for this. cheers, Martin
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