CTBUH Journal 2021, Issue III

29 September 2021

A special report on carbon, covered from a variety of angles including emissions reduction strategies, embodied carbon, and net-zero tall building design best practices.

CTBUH Journal 2021, Issue III, a special issue on carbon, is now available for download and in print. The issue addresses the topic of carbon from a variety of angles, including best practices in tall building design towards net-zero (Sustainable Tall Building Design Exemplars), emissions reduction strategies (Tall Buildings in Numbers data study), and the role of embodied carbon (Towards the Carbon-Neutral High-Rise), among others. In Talking Tall, the City of Helsinki's  chief design officer looks to a carbon-neutral future. 

Inside this issue

Many of the world’s cities have committed to 2030 as their net-zero target, a daunting nine years away and counting. We first must agree on defining “net-zero” before we can corral our efforts to achieve it—witness the discussion in Debating Tall

The main distinctions, and pressing questions, revolve around how to account for, and reduce embodied energy, and the sources of the operational energy we use to run our buildings. Although no single article can definitively answer this question, it is worth reflecting on some stellar tall building projects constructed over the past decade or so to understand where we stand now, and to feel confidence that we have many of the tools already at our disposal (see the CTBUH Special Report Sustainable Tall Building Design Exemplars and Tall Buildings in Numbers: Emissions-Reduction Strategies). A number of the examples in the report are actually retrofits and adaptive-reuse projects. 

The principle espoused in these examples is reinforced in our Ask a CTBUH Expert piece, How to Ensure Tall Buildings Are Built to Last? where the “first do no harm” approach to tall building construction is clearly elucidated. Another clear-eyed assessment of the relationship between embodied carbon and the tall building industry, especially in growing markets such as Asia, can be found in Tall Buildings and Life Cycle Approaches: A Debate That Must Be Started, which catalogues the result of a CTBUH research project into life cycle cost analysis (LCCA), kindly sponsored by the South East Asia Iron and Steel Institute (SEAISI.)

Depending on your viewpoint, concrete can either be considered a hero or villain of modern civilization.
- Law

Much of the issue contains papers that apply research and current best practices to optimized near-future conditions. These include the highly developed proposal for the Hybrid Timber Tower for a site in Toronto in The Zero-Carbon Hybrid Future of Tall Timber, while the most common tall building material, concrete, is subjected to the question, “Is a Zero-Carbon Concrete Skyscraper Possible?” 

Towards the Carbon-Neutral High-Rise: The Role of Embodied Carbon examines the “wickedest” question in this global business, by way of examining an innovative mixed-use project in Abu Dhabi that lowers the quantity and optimizes the deployment of the ubiquitous concrete, if not eliminating it entirely. 

As the pandemic and other global crises have shown, some national governments seem more capable of decisive action. When it comes to enacting progressive carbon-reduction policies, it has largely been left to cities, which are in many ways the battlefields where the carbon war is being fought. The CTBUH Journal had the privilege to interview Hanna Harris, Helsinki’s (and the world’s first) Chief Design Officer, for Talking Tall in this issue. Harris is one of the city officials charged with making sure Helsinki meets its own goal of carbon neutrality by 2035.Our hope in presenting this material is to provide a frank assessment of the present and the potential for the near future, while echoing the urgency with which it must be approached. We hope you will agree with this emphasis, and join us in the battle charge, towards net-zero.

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