Uta Hassler

Resilience in the built environment

A new arena? Resilience, as a design principle, was an implicit part of traditional construction knowledge before the 19th century. The oversizing of components and spaces, redundancy, and reparability were forms of tacit construction knowledge (Schön, 1983) that enhanced the resilience of buildings. In contrast, the modern engineering concept of resilience originated from material technology in the 19th century. This modern approach replaced the traditional dimensioning rules by formal rules of calculation (based on experiment) in order to optimize both (structural) safety and the (reduced) consumption of materials. Resilience as a long-term design principle and resilience as a functional, disciplinary model (i.e. the application of resilience in structural engineering) are not identical; and in some situations can be contradictory. The former approach provides for unknown uses and adaption, the latter focuses on providing a specific, tailored solution to one particular brief and set of functions.

Research on the building stock and its applications

Traditionally, architects and engineers were interested in designing new buildings, town planners and political authorities in planning the growth of settlements and cities. Their ideas are still strongly conditioned by the post-1945 boom, which has doubled the building and infrastructure stocks of most European countries. The centre of interest has been in expanding, open systems. But over the last few years, clear new trends have appeared: interest is shifting gradually from managing growth to managing saturated steady-state situations. Indeed, there is also recognition on the need to manage the decline (or shrinkage) of the built environment. In the building context, a stock-centred view replaces the fascination for continuous growth in input flows, and the ignorance of output flows and side-effects. Kenneth Boulding anticipated this shift from ‘cowboy economics to spaceman economics’ more than 40 years ago:

The ideal of resilient systems and questions of continuity

The importance of resilience is contextualized within the sustainable long-term management of the built environment. The built environment is considered as a set of different capitals (natural, physical, economic, social and cultural) with limited possibilities for substitution between the capitals. Resilience is related to other concepts used in the search for a sustainable development of the built environment: continuity, stability and equilibrium, duration and durability, robustness and vulnerability, fast- and slow-moving risks. Cultural capital (in its material and intangible forms) as well as natural capital are significant due to long foresight considerations, high uncertainty and limitations on substitutions. Different time and scale categories and the conservation of different capitals need different anticipation and resilience strategies. It is argued that natural and cultural capitals can be transmitted if they are conservatively used and if adaptation occurs slowly. Specific strategies are needed for the ‘non-recoverability’ of cultural capital.

Implications of climate change on heritage

Introduction Cultural heritage, and the historic environment in particular, are subject to a multitude of diverse threats. These range from climate, pollution and natural disasters to economic pressure, development projects and uncontrolled tourism. Knowledge about the type of threat, the associated risks and, above all, the temporal incidence allows one the possibility to react in advance (prevention) and manage the consequences as far as possible (mitigation).