Is there a sustainable form of city architecture?
In response to the negative impact of urbanisation on the environment, a new form of inventive, experimental architecture is emerging around the world. How can architecture become sustainable by offsetting the waste it produces and the resources it consumes?
A sustainable city cannot exist without sustainable architecture. This means buildings that better respect the environment and ecology while serving their occupants' health and well-being. The architects involved in this approach strive to adopt a global vision that considers all economic, environmental, and social impacts. In urban planning projects, architects have different means at their disposal to design sustainable housing.
While the French low-energy building standard (BBC) has become the norm for new buildings, sustainable architecture takes things further by aiming for energy neutrality or designing buildings that generate more energy than they use. To achieve this, several green energy production methods can be used, for example solar panels, solar energy boilers, or domestic wind turbines.
Net positive energy buildings (BEPOS certification)
A net positive energy building produces more energy than it consumes. The 16-storey Elithis Danube tower in Strasbourg is a good example of this type of building. It produces 112% of its total energy requirements thanks to its solar panels and its innovative architecture, which offers high performance thermal insulation.
A sustainable building must produce its own energy, but it must also reduce its energy consumption with high performance insulation. The choice of materials is crucial. Sustainable architecture uses materials such as wood, stone, aerated concrete, hemp lime or recovered materials such as industrial containers.
The orientation, shape, and size of the building
In general, north-facing walls have few openings while south-facing walls are more open. The greater the external surface area, the more heat is lost, so a smaller, more compact building will lose less heat. Plant-covered walls can also protect the building from the sun and create a layer that will retain heat.
Ecological architecture uses the environmental conditions of the building's location to reduce its energy use. This innovative design process has three underlying principles: capturing sunlight, transforming and circulating the sun's heat throughout the building, and retaining heat with effective insulation.
Waste management uses energy. Sustainable architecture integrates systems for sorting and composting waste and collecting rainwater. In addition, the energy used to eliminate waste can be recycled: heat pumps can heat water and/or air via a thermodynamic process.
The latest trends in sustainable architecture
Some believe that sustainable architecture is not a discipline in its own right but rather a way of designing buildings that prioritise technical solutions without observing a given architectural style, or architectural harmony. Eco-neighbourhoods are often distinctive with colourful buildings that use materials such as wood and plant-covered walls or roofs. Some ecological architects use organic forms, for example blob architecture, a trend in which buildings have a wavy or curvy design.
An even more experimental architectural trend is becoming increasingly popular – upcycling, which involves reusing materials indefinitely. This allows for zero-waste, fully recyclable sustainable buildings that can be dismantled at the end of their useful lives before being reused elsewhere in a different form. This concept has yet to make a breakthrough in France, but some projects are beginning to take shape.