On the human and social level first, the world population will grow from 7,9 billion in 2021 to an estimated 9,7 billion in 2050, with a rate of urbanization rising from 55% in 2020 to an estimated 68% in 2050. This enormous challenge puts pressure on cities’ infrastructures such as sewage systems, energy and water supplies, housing, and jobs.
Then, by appropriating about 40% of global energy, 25% of global water, 40% of global resources, and representing 1/3 of the Global greenhouse gas (GHG) emissions, the building sector continues to place a huge burden on the ecological and economical categories.
The implementation of environmental agreements also push the building and construction industries to reduce greenhouse gas emissions. In the 2015 Paris Agreement (COP 21), 196 countries agreed to work together to halt global warming and limit the temperature increase to 1.5 degrees Celsius, compared to pre-industrial levels, by instituting various plans and actions to reduce emissions.
The EU has also set a target to reduce GHG emissions by at least 50% by 2030 (compared to 1990), to increase at least 32% in the share of renewable energy, and to improve at least 32.5% in energy efficiency.
Furthermore, in the European Green Deal (December 2019), the European commission pledged to transform the EU 27 from low to neutral carbon economies by 2050 through a set of policy initiatives and programs. At a national level in Portugal, the 2016 PNEC (Plano Nacional Energia e Clima 2021-2030) promotes the decarbonization of the economy and the energy transition, aiming at carbon neutrality in 2050.
Applying a sustainable approach to urban management, building refurbishment, and construction provides answers to these challenges.