Aksözen, M., Hassler, U. and Kohler, N. (2016) Reconstitution of the
dynamics of an urban building stock, Building Research &
Information.
DOI: 10.1080/09613218.2016.1152040
Supplemental data
Materials and Methods
Due to their complexity, building stocks are generally subdivided into different levels of analysis. The
building stock of Zurich was analysed on three different levels, defined by different approaches,
methods and data sources:
Level 1: City of Zurich
Level 2: Districts and quarters of Zurich
Level 3: Individual buildings
Figure 1 Plan of the city of Zurich in 1504 (Keller & Hegi, 1829) and in 1824 (Keller & Scheuermann, 1824). The
city develops gradually within the town wall until their demolition after 1832. See also (Dändliker, 1908) –
former figure 1
In this work, the focus is on the City of Zurich. Level 1 comprises the whole stock (55’000 buildings in
2010) and its development since 1832, i.e. all buildings that have existed or still exist inside the
spatial limit of the commune of Zurich in 2010. The communal territory has been extended in the
years of 1893 and 1934 by the integration of suburban communes. A special historical analysis
concerned the development since the 14th century (source j) with maps from 1504 and 1824 (Keller
plan, Figure 1).
Building stocks can be described by a simple use-age-size matrix. Table 1 shows in a condensed way
the quantitative structure of the stock in 2010. There are four use classes (single family, multiple
family, domestic with other use and non-domestic buildings).
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Table 1 Composition of the stock in 2010 by four use and four age classes with average age of buildings, number of
buildings, gross floor area, volume and footprint (in % of total)
There are slow increases and decreases for the number new constructions and demolitions. Around
the year 2000, the number of demolitions exceeds the number of new constructions for the first time
within the period between 1931 and 2010 (Figure 2).
Figure 2 Number of new constructed buildings (black line) and demolitions (red line) per year 1931 – 2010 (10
year sliding average) – former figure 13
Figure 3 and Figure 4 shows the evolution of the population (source h and j) and the number of
buildings for the central, historic district. The number of buildings stays constant over 4 centuries
(even if there is a slow and constant densification). The population increase from 1810 on (beginning
of the industrialisation) clearly precedes the increase of buildings, which reaches a maximum around
1910. The decrease of population and number of domestic buildings after 1920 go parallel. This is
more due to a change in the classification than to demolitions. From 1950 on the population, living in
the city, remains constant and then decreases and the non-domestic building uses increase. There is
an important and on-going densification of non-domestic buildings by adding floors (roof and
additional basements.)
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Figure 3 growth of the domestic stock (number of buildings in orange, left axis), non-domestic buildings (grey)
and population (number of persons in blue, right axis) 1410-2010 of the historic center of the City of Zurich
(Altstadt – District 1) – former figure 5
Figure 4 growth of the domestic stock (number of buildings in orange, right axis) and population (number of
persons in blue, left axis) 1830-2010 in the City of Zurich - – former figure 6
Figure 5 and Figure 6 show the complementary development of the historic core, the city
with the communal limits and the agglomeration.
Figure 5 growth of the population 1410-2010 of the whole City of Zurich (light) and of the historic district of
Zurich (dark) - – former figure 7
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Figure 6 growth of the population 1850-2000 in the agglomeration of the City of Zurich with its 5 suburb belts –
former figure 8
Figure 7 growth of the domestic stock (number of buildings) 1860 to 2000 in the agglomeration of the City of
Zurich with its 5 suburb belts – former figure 9
The growth of the agglomeration that became dominant from 1950 on does not have a clear limit yet
(physical or institutional, Figure 7 and Figure 8). There is a growing importance of the public
transport system on the agglomeration. Today the region is composed of 101 communes (Statistik
Stadt Zürich, 2001), p.30.
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Figure 8 Communes of the agglomeration of the region of Zurich -– former figure 10
Figure 9 shows the volume of buildings related to type of building and size of building (2010). This
representation, which has been suggested by Statistik Stadt Zürich (Mischler, 2005) for the year 2004
and was adapted for the year 2010. The horizontal axes indicate the building size (volume,
logarithmic scale) and the vertical axes shows the total volume contribution of the different types.
The one family buildings are small even if there is long tail of large villas. The difference between
domestic and exclusively non-domestic buildings is considerable (Figure 10). The exclusively non-
domestic buildings are in average much bigger than domestic buildings. This difference has to be
kept in mind when arguing on the level of the whole stock. When comparing buildings stocks these
differences must be taken into consideration.
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