Tools for circular construction

Next months, these posts deal with the challenges of Earthlings of bringing humane cities closer. These posts represent the most important findings of my e-book Humane cities. Always humane. Smart if helpful, updates and supplements included. The English version of this book can be downloaded for free here and the Dutch version here

Structural waste in the build environment. Source: The circular economy: Moving from theory to practice, McKinsey & Company 2015

The impact of circular principles in the construction sector is huge, because buildings are responsible for more than 50% of the total use of materials on earth, including valuable types such as steel, copper, aluminium and zinc.  Moreover, they produce about 40% of all greenhouse gases.

By circular construction we mean designing, building and demolishing a building in such a way that, in addition to the high-quality reuse of materials, justice is done to sustainability ambitions in the field of energy, water, and biodiversity and ecosystems.

In case of demolishment, nowadays many components are reused, but at a very low level, for instance concrete and stones as the foundation of new roads. Apart from the question how many new roads are still needed, this type of recycling destroys the intrinsic quality of materials and does not diminish the recovery of new materials. At least, separation of glass, steel, wood and other materials can be made mandatory. In addition, valuable materials can by ‘saved’ by operating in a targeted manner, even though these buildings are anything but circular. This is called ‘urban mining’. The biggest problem is that recycled materials are often more expensive than new ones.

Anyway, a first step is more efficient use of existing buildings. Evidently, progress can be made by planning, designing, developing and building circular buildings. A number of options are mentioned below[1].  

Urban planning

Challenges for planning are the use of inner-city vacant land and issuing mandatory requirements regarding the construction of new buildings, for instance the use of less cement, glass and steel, the mandatory application of a certain percentage of reused materials, and becoming energy positive or at least energy-neutral. Switching to sustainable timber is an option for 90% of homes and 70% of offices being built.

Mandatory reuse of existing components

Reuse of existing materials means than glass is reused as glass and concrete pillars as pillars. The same applies to doors, frames, carpets, wall-cladding materials and so on. 

The materials passport, which contains an overview of all materials and components that are used to construct of a house or building, is a useful tool as well. The obligation to reuse a large percentage of existing components has far-reaching consequences for the design and construction of new houses. To start with, after demolishment all materials must be selected, cleaned, registered and stored in new-to-develop warehouses.

The Circl pavilion of the ABN-AMRO bank

The Circl pavilion of the Dutch ABN-AMRO bank is an example of a new building that uses as many existing components as possible. For instance, 1200 m2 of wooded floors, partition walls of a demolished building and 16.000 garments of employees for isolation purposes. All components of the building are designed to be reused[2].

Industrial production and 3D printing

Construction of components in factories, deploying industrial processes, will reduce costs by 30 percent and the delivery time by at least 50 percent.

Decreasing size of apartments

The size of apartments will decrease, partly due to costs, but also because of the presence of shared guest rooms, lounge areas and terraces for working and socializing, spaces for washing and drying laundry.

The need for office space will decrease rapidly due to sharing space and working in an external environment. So IBM has only one desk available for 12 employees. Given the presence of 300,000 employees, this has led to savings on real estate of around € 1 billion in the past 10 years. 

Modularity and durability

A key barrier for better use of floor space is the lack of flexibility in the design of buildings and room configurations. A modular design, which provides for easy replacement of partitions and placement of complete functional units (kitchens and bathrooms) facilitates adjustments as the use of a building changes.

Forget new construction at all

As families become smaller and offices need less space, existing space becomes more underused. Well-thought adjustments to the lay-out of existing houses and buildings can improve their efficiency without reducing their amenity. That is what adaptive reuse stands for: instilling a new purpose on an existing “leftover building.”. A number of inspiring examples can be seen here[5].






Resilience and prediction of hazards

Next months, these posts focus on the challenges of Earthlings of to bring humane cities closer. These posts represent the main findings of my e-book Humane cities. Always humane. Smart if helpful, updates and supplements included. The English version of this book can be downloaded for free here and the Dutch version here

In my last post, I elaborated on resilience. Resilience has two sides. At the one hand it has to do with policy aimed at anticipation and mitigation hazards. At the other hand, it refers to the capacity of both government and citizens to deal with their impact.

Anticipating hazards

The most difficult problem in anticipating hazards is knowing what hazard to anticipate. This is difficult, given the long list of chronic stressors and acute shocks that can affect a city. Emergency plans should focus not only on the most likely disasters, but on all conceivable ones. Listing possible threats is not that difficult: plane crashes, terrorists blowing up a dam or shooting visitors during a football match, previously unknown massive and violent protests, outbreak of a hitherto unknown deadly disease, an attack by a foreign power or, if you want, aliens, et cetera.

It is impossible to make separate plans for all these threats. The preparation should take place on a more abstract level. For example, what to do if roads are impassable, many people have died, there is no electricity, water and gas, an evacuation must take place within a few hours, et cetera. Agreements must be made in advance about outside assistance, and which means of communication can be used permanently.  

Citizens should be involved in these activities. Otherwise, they will become dependent on government initiatives, which will not come as the command center is destroyed.  Citizens should be trained in self-management complementary – or in case of emergency – to replace official actions.

Anticipating hazards is easier if some types of hazards are a recurring phenomenon, such as flooding. Activities include installing early warning systems, preparing emergency services, providing scenarios for the evacuation of the elderly and the sick, allocating places for temporary housing, gathering tents, organizing access to food, drinking water and to medical care. The faster and more accurate the prediction is, the better the preparations can be.

Flood Concern creates map-based visualizations of places where floods can hit hardest, up to five days before an approaching storm using artificial intelligence. These are simulations in the form of time-lapses of how the water will rise, at what speed and in which direction.  These maps also indicate which parts of the infrastructure will flooded or wash away, and how mitigation efforts – from sand backs to opening locks – will turn out. With this data, emergency services can determine which roads are still accessible, and plan evacuation routes accordingly. 

Dealing with impact

If accurate forecasts are available, the government, together with citizens, can implement previously designed and trained plans to mitigate the effects of the flooding. However, anybody must stay vigilant to respond to unexpected changes in the anticipated course of events. 

One of the most dramatic cases to discuss is the massive earthquake that devasted all of Haiti on January 12, 2010, claiming 316,000 lives, injuring another 300.000 and displacing more than 1.5 million people. The earthquake was just the beginning:  In the following years other devasting natural disasters caused thousands of new deaths, engraved famine, and a deadly cholera epidemic, wiping out ongoing efforts to rebuild the country. Until now, millions of Haitians are still in need of humanitarian aid and many still live in camps without proper sanitation and drinking water. To date, the international community has raised € 8 billion in aid. What it was used for is unclear, in spite of a large number of helping hands. It seems that the rebuilding of the country is mainly due to the inhabitants themselves, who started rebuilding their primitive huts again and again by using the remains of their previous emergency shelters. The government infrastructure was destroyed by the dictatorial regimes of father and son Duvalier and led, among other things, to the depart of most residents with some education. So the country had done nothing to prepare for a possible disaster, and there was no policy to cope with its consequences.

It is evident that dealing with the impact of hazards depends from te degree of anticipation. Otherwise, full reliance on social capital is the only hope.