DISTRICTING 71 



Districting in German cities 1 



Districting is most fully developed in German cities. There it is known 

 as the zone system. The term zone was particularly appropriate in Germany 

 where special regulations were applied to the successive belts of building 

 development surrounding the central walled city. At present, however, in 

 many German cities the districts are not concentric zones, and the system 

 might more appropriately be called the " district system." 



The district system is a method of regulating buildings as a part of a 

 general city plan. It has two characteristics : it groups buildings of different 

 classes and it limits the density of buildings progressively, allowing build- 

 ings to be higher, and to cover more of the lot in the centers where land 

 values are greater and business needs require more concentration, and 

 making the requirements more and more severe as the distance from these 

 centers increases. 



Under the German rules the height of buildings is invariably regu- 

 lated with relation to the width of the street upon which the building is 

 situated; and also, usually, by a maximum which, irrespective of the width 

 of the street, it must not exceed. In many cities, in the zone or zones 

 of greatest concentration, a height a little in excess of the street width is 

 allowed; in the other zones it must not exceed that width, and in the 

 outer zone or zones the maximum limits it to less. Usually, too, there are 

 minimum courts, and all rooms constructed for the residence or long con- 

 tinued business use of mankind must have a window upon a court of at 

 least a specified size. The proportion of the lot that may be covered by 

 buildings, also, is almost invariably limited progressively, buildings on cor- 

 ner lots in each zone being allowed to cover more than those on inside lots. 

 The ordinances in the different cities differ in detail, but in general the 

 system is the same. The provisions of the Frankfort ordinance illustrate 

 «it as well as any other : 



The older inner city is the first zone or district. Here the highest build- 

 ings are allowed. They must not exceed the width of the street, plus about 

 10 feet (three meters). Or in any case, however wide the street, about 66 

 feet (20 meters). This is to the cornice; the roof above this is restricted 

 by an angle, and in no case may exceed about 30 feet (nine meters). The 

 roof is more than mere roof ; it is a roof story, in which there are rooms, 

 which, however, may not always be used for residence. The number of 

 stories is also restricted; in this zone it must not exceed five, and the roof 

 story. 



Here in the inner city, also, the greatest proportion of the lot may be 

 covered with buildings, three-quarters — for corner lots, five-sixths. Factor- 

 ies are allowed but are not numerous. Solid blocks are permitted. The city 

 here presents the appearance of being fully built up to a fairly uniform 

 height. 



1 A complete report on " The German Zone Building Regulations," prepared by- 

 Frank Backus Williams, is contained in the Report of the Heights of Buildings Com- 

 mission, 1913, at page 94. 



