Almost 40% of global carbon emissions can be attributed to the building sector, which makes the built environment both a liability and an opportunity to mitigate climate change. Building for Zero summarizes the challenges the building industry faces on the way to zero emissions. A global scenario and an interactive calculator show how embodied and operational carbon, retrofit rates and grid decarbonization relate to each other.

Ramon Weber, Caitlin Mueller, Christoph Reinhart · Digital Structures Group & Sustainable Design Lab, MIT · 2021

The challenge

Net zero by 2050.

International organizations and many countries have set the goal of net zero emissions for all industries by 2050 to avoid irreparable damage to our planet’s climate and ecosystems. The question is whether and how society can meet this target.

The world

Global floor area will almost double.

The United Nations and the International Energy Agency estimate that the floor area of all buildings in the world will almost double from 2017 to 2050. The ratio between existing and newly built area varies greatly between regions, so different strategies are needed for making new buildings more sustainable and for retrofitting the existing building stock.

The model

Three scenarios for the built environment.

To understand what global carbon budgets mean for buildings, housing policy and development, we model carbon emissions from buildings between now and 2050. Business as usual assumes a 1% renovation rate and a linear decrease of building operation emissions to net zero until 2050. Net Zero Operational Carbon assumes a 5% renovation rate and a linear decrease of operational emissions to net zero between 2030 and 2040. Net Zero Operational and Embodied Carbon assumes, in addition, a linear decrease of embodied carbon for construction and maintenance to zero between 2030 and 2040.

The calculator

Try it: can the building stock stay within its carbon budget?

The interactive calculator estimates the carbon emissions of the global building stock until 2050 for the three scenarios. Four inputs can be changed: 1) the global emission scenario and carbon budget, based on one of five shared socioeconomic pathways (only SSP-1 has a probability of reaching the UN climate goals); 2) the global annual building renovation rate; 3) the year by which all new construction is carbon neutral in operation; and 4) the year by which all new construction is carbon neutral in embodied carbon. The outputs show yearly emissions until 2050 and whether each scenario stays under the carbon budget set by the IPCC.

The models are published open-source on Observable. The full methodology is outlined in the report.

Report

Building for Zero, The Grand Challenge of Architecture without Carbon
Ramon Weber, Caitlin Mueller, Christoph Reinhart
SSRN Electronic Journal, 2021 · https://doi.org/10.2139/ssrn.3939009

@article{weber2021buildingforzero,
  title     = {Building for Zero, The Grand Challenge of Architecture without Carbon},
  author    = {Weber, Ramon and Mueller, Caitlin and Reinhart, Christoph},
  journal   = {SSRN Electronic Journal},
  year      = {2021},
  issn      = {1556-5068},
  publisher = {Elsevier},
  doi       = {10.2139/ssrn.3939009},
  url       = {https://doi.org/10.2139/ssrn.3939009}
}