Graduate geogr. Daniel Kretzschmar

Stock dynamics of non-residential buildings in Germany

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Abstract

In contrast to residential buildings, data on the stock dynamics in the non-residential building sector are scarce in Germany. The aim of this thesis is to identify factors that influence changes to the non-residential building stock and to quantify their influence. Using a suitable typology of non-residential buildings, a preliminary selection of influencing factors will be obtained from an expert survey. These factors will then be regressed on the change of the non-residential building stock. The analysis will also consider building ownership, community size and population development within selected geographical submarkets. As a result this thesis might contribute to a more informed debate about the future development of the non-residential building stock.

Introduction

Compared with all other sectors of the built environment in industrialised nations, the building stock contains the largest stock of material. Knowledge of the composition and dynamics of the building stock is therefore crucial for the sustainable development of this built environment. Clearly, non-residential buildings make up a considerable part of the building stock. In 2016, around 33% of the gross fixed assets of the Federal Republic of Germany were in the form of non-residential buildings [STATISTISCHES BUNDESAMT (2016)]. Also in 2016, about half of the new living and functional space in newly constructed buildings in Germany was in this sector [STATISTISCHES BUNDESAMT (2017)].

While the dynamics of the housing stock can be well explained by demographic and behavioural influences such as population trends, changes in the number of households as well as the behaviour-dependent housing requirements of households, no such clear causality has so far been identified in the non-residential housing stock. This is due, on the one hand, to the strong heterogeneity of this stock along different functions, building age classes, ownership structures and industrial/sectoral affiliations, which multiplies the number of possible correlations between the development of the stock and the development of potential influencing factors. Hence, any attempt to systematically identify relevant correlations requires that the large stock of non-residential buildings be classified into suitable and clearly distinguished forms of use. On the other hand, the inadequate provision of data and data collection by public statistical agencies hinders this classification process [CLAUSNITZER ET AL. (2014)]. The large functional diversity in the non-residential stock means that there is also a wide diversity of scientific studies in this field, in which the various scientific disciplines often focus on only a sub-sector of the stock, thereby ignoring the ecological implications of resource consumption, land consumption or the productivity of raw materials of the sector as a whole.

Accurate information on shifts in the dynamics of this sector of the building stock and the underlying causes are, however, essential for a comprehensive understanding of the built environment and its future challenges. Such information will provide a stepping stone to further scientific research as well as the basis for sound political decisions based on the findings of this research.

Research Aim

The general research aim is to measure the influence of external factors on the different use classes within the non-residential building stock. In particular, the aim is to investigate those external and internal factors which influence the development of different use classes of the non-residential building stock and whether (in the form of if-then statements) there are correlations between the development of these influencing factors and the development of the stock (according to their floor space).

The study will encompass the development of a methodological concept to take into account previously defined criteria of relevance, of data availability, of comparability as well as spatial and sub-market generalisability for different use classes of the non-residential building stock. In this way it will be possible to capture, systematise and reduce the wide range of possible factors in a suitable spatial delimitation to the primary influencing factors. The first step is to identify a typology of the non-residential building stock that reflects the research interest. This typology will then be combined with suitable statistical methods to analyse the influence of external and internal factors on the stock dynamics (differentiated according to stock inflows and outflows) in the non-residential building stock. The intent of this investigation is to be able to derive some generally applicable findings.

Research Questions

1. What factors influence the stock dynamics of non-residential buildings?
2. How does the interdependency change along different use classes, forms of ownership and sub-markets?
3. What influence do long-term building cycles have on the development of certain use classes of non-residential buildings?