‘RhinoCircular: Development and Testing of a Circularity Indicator Tool’ at AIA ACSA Intersections Conference: Carbon

Felix Heisel and Cameron Nelson present their paper RhinoCircular: Development and Testing of a Circularity Indicator Tool for Application in Early Design Phases and Architectural Education at the AIA ACSA Intersections Conference: Carbon on October 1st, 2020.


Globally, the construction industry is the biggest consumer of energy and materials. Over their full life cycle, buildings account for nearly 40% of energy use and greenhouse gas emissions, as well as 50% of raw material extraction and solid waste production.[1] Since rates of construction are significantly higher than demolition and discard, society is building up an important economy-wide anthropogenic material stock.[2] The concept of the circular economy (CE) is increasingly gaining attention as a way to overcome the social, economic and environmental problems of this linear economic system.[3]

Activating the built environment as a material reserve for the construction of future cities would not only provide valuable local resources, but also potentially prevent up to 50% of the industry’s emissions by capitalizing on embodied carbon.[4] However, this requires radical paradigm shifts in (1) how we design and construct buildings (materials selection / design for disassembly), and in (2) how resources are managed within the built environment. Buildings and regions need to anticipate stocks and flows of materials, documenting and communicating which materials in what quantities and qualities become available for re-use or recycling where and when. The emerging concept of materials passports provides digital twins of such buildings, containing detailed inventories of materials and products used, as well as their specific information. Standardization and central registration of such passports in material cadasters (comparable to a land registry) will be a prerequisite for the circular management of resources.[5]

However, the application of material passports has been concentrated on the documentation of existing buildings so far. This paper describes the development of tools for the early design phase and architectural education. Developed within Cornell’s Circular Construction Lab, the Rhinoceros/ Grasshopper plugin allows a direct and immediate feedback on design decisions in respect to formal deliberations, structural considerations, material selection and detailing based on a Circularity Indicator. This paper will highlight the functionality of the tool and provide results from its application in architectural design studios and real case studies.


[1] International Energy Agency and the United Nations Environment Programme (2018): 2018 Global Status Report: towards a zero‐emission, efficient and resilient buildings and construction sector;     Transparency Market Research. 2020. “Construction Waste Market – Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2017 – 2025.” Pre-Book Report. Albany, NY.

[2] Müller, Felix, Christian Lehmann, Jan Kosmol, Hermann Keßler, and Til Bolland. 2017. “Urban Mining: Ressourcenschonung im Anthropozän.” Für Mensch und Umwelt. Dessau-Roßlau, Germany: Umweltbundesamt.

[3] Ellen MacArthur Foundation. 2013. “Towards the Circular Economy Vol 2: Opportunities for the Consumer Goods Sector.” 2. Rethink the Future. London, UK: Ellen MacArthur Foundation; European Commission. 2014. “Towards a Circular Economy: A Zero Waste Programme for Europe.” COM(2014) 398 final. Brussels, Belgium: European Commission; Hebel, Dirk E., Marta H. Wisniewska, and Felix Heisel. 2014. Building from Waste, Recovered Materials in Architecture and Construction. Berlin, Germany and Basel, Switzerland: Birkhäuser;

[4] Architecture 2030. 2019. “New Buildings: Embodied Carbon.” 2019.

[5] Heisel, Felix, and Sabine Rau-Oberhuber. 2020. “Calculation and Evaluation of Circularity Indicators for the Built Environment Using the Case Studies of UMAR and Madaster.” Journal of Cleaner Production 243 (SI Urban Mining): 118482.