Our 2050 Roadmap: The 5C Approach
The built environment of tomorrow will have sustainability at its core. Sustainability in its three pillars: built structures will need to be safe, durable and affordable (social pillar), need to respond into the quest for CO2 and energyefficiency (environment pillar) and construction and renovation will need to remain a key driver for growth and jobs (economic pillar), as strongly emphasized in the Renovation Initiative launched under the Green Deal./p>
Concrete ticks all these boxes and is clearly instrumental to tackle the needs of the construction sector. Concrete is one of the most versatile and cost-effective building materials. It offers a working life in excess of 100 years, provides fire resistance, and is able to reduce energy consumption for heating and cooling by 25%. This opens significant opportunities to reduce emissions not only for concrete itself, but for the overall construction sector.
How can we reduce emissions in construction?
Energy efficiency in buildings
Currently 72% of CO2 total emissions related to an average building come from the energy used during its working life1. Buildings that leverage the thermal mass properties of concrete can cut energy use by 25% and up to 50% during the peak demand periods. Examples include a multi-story social housing project in Mühlgrundgasse, Vienna, residential passive house building in Lärkträdet in Vara, Sweden and The Edge, multi-story office in Amsterdam. Thermal mass can also be incorporated into re-use of buildings where thermal mass is added to the concrete structure being refurbished for a new building use.
Concrete used in buildings
Research is currently underway to look at ways of reducing embodied carbon of construction materials. This, however, must be done ensuring that it does not lead to premature structural failures and guarantees the durability and working life of a structure. Early research has shown that, by using efficient structural design, we can reduce embodied carbon by up to 30% for certain types of buildings. Improvements in building construction can also be realised using 3D printing.
Recent studies point out that a more efficient use of concrete in buildings and other construction projects can reduce the concrete used in these structures. The chart for 2030 includes a 5 to 10% and for 2050 a 10 to 30% reduction in concrete use in structures. These reductions have not been included in the savings as they may well be offset by increased demand for concrete in projects to protect against flooding, infrastructure projects for mass transport systems and for increased renewable energy.
Design for Adaptability and Disassembly
Office building structures are often designed for multiple use, so an office block can be converted to an apartment building if the demand for office space in the area declines. Some buildings have been designed using concrete structures that can be adapted to the needs of the tenant, resulting in a mixed-use building. The durability and longevity of concrete perfectly lend themselves to such adaptations to the changing needs of the market. For older buildings there is a move towards re-using the concrete structure of a building rather than demolishing it entirely.
In this context, our sector is also keen to explore the “design for deconstruction” model where a building is conceived at origin with the objective to disassembly at end of life. The approach allows materials and components to be removed easily and to be re-used to construct a new building.
 WorldGBC-Bringing Embodied Carbon Upfront – pg16
How can policy support this transformation?
The European Green Deal rightly puts an emphasis on the construction sector and the idea of circularity in buildings. It is critical that ambitious policies are set up in this field.
A more circular approach to buildings is key to reduce emissions. Policies should maximise the different properties of construction materials including their durability, recyclability, thermal mass or re-carbonation potential.
Innovation in action
Some examples of research projects aiming to reduce CO2 emissions
This is a research project to look at more efficient use of concrete in building design.
Technical University of Vienna
The multi-story building of the Technical University of Vienna (TUV) has a positive energy footprint by using thermal mass and solar panels.