A circular impulse for public space in post-war neighbourhoods
A large part of the ecological footprint of municipalities is caused by the design and construction of public space. In addition, public space is the place that offers coupling opportunities for tackling circularity and other sustainability themes. Therefore, we investigated how the steps of a circular process can contribute to larger transitions in public space, such as CO2 reduction, climate adaptivity, water nuisance and heat stress.
Post-war neighbourhoods were built at a rapid pace with practical application as the starting point. These neighbourhoods therefore have a large amount of surfacing, often consisting of materials such as asphalt and concrete that have a large environmental impact. However, we should not regard these locations as places with a high environmental impact, but rather as rich sources of material.
In this research, circularity was taken as a starting point to enable greater transitions in post-war neighbourhoods. However, by doing the research, we realized that taking into account other transitions as starting points is more effective. Otherwise, it is more difficult to achieve a big impact on circularity and the environment. The research was carried out in close cooperation with the municipality of Leiden and experts in the field of circularity.
Public space typologies
In order to paint a good picture of the public space in the post-war neighbourhoods, a palette of five public space typologies was chosen that are common in the Netherlands. At present, they are often functionally laid out, with much space taken up by paving and cars (storage and use). These are the public spaces where sewer replacements will be needed in the coming decades, offering the opportunity for future-proof redesigns that pay more attention to biodiversity, energy transition, circularity and mobility transition. This will create a more attractive and better living environment.
A circular chain
A shift from linear to circular processes is an important condition for reducing the impact of climate change. Several changes are needed before circular principles can become successful in practice. First of all, it is necessary to appreciate the current materials and to see the (post-war) neighbourhoods as sources of materials.
The mobility transition can also make a major contribution to circular streets. After all, less traffic means less paving and more space for greenery, ecology and related functions. The reorganisation of the underground is an important aspect for the life span of streets. By constructing underground infrastructure in a compact way, less material needs to be broken up at the time of maintenance. This will lead to less material loss and inconvenience caused by work.
The maintenance of greenery currently costs a lot of money, effort and energy. Alternatives to green space maintenance can be considered, especially by allowing it to take place in a more natural way. One example is grazing sheep instead of mowing with an electric lawnmower. When rebuilding the streets, the drainage and permeability of the pavement must also be taken into account. Heavy rainfall must be absorbed in the public space.
All these transitions will have an impact on the daily lives of residents. A cultural mind shift is therefore required among both residents and politicians in order to provide space for the transitions. Participation, inclusiveness and education are important elements in this.
The analysis has led to a number of important principles that should be kept in mind when designing for the future. In addition, it was also found that there is the potential of reducing up to 50% of the amount of hard surface in these neighborhoods. This would mean that if the system gets figured out, municipalities would not need to invest in new resources for a while.