DIALOG develops system to build 105-storey hybrid timber towers

by sadia_badhon | October 2, 2020 10:46 am

By Sadia Badhon

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Design firm DIALOG[2] has developed a prototype design that could see hybrid mass timber towers sprouting in major cities and climbing as high as 105 storeys.

The patent-pending design will also produce hybrid timber towers that are zero-carbon—a made-in-Canada solution to one of the world’s most pressing issues: climate change.

DIALOG’s prototype hybrid timber floor system (HTFS) would use a unique combination of sustainably harvested timber, steel, and concrete. The system will allow for hybrid wood buildings with fewer support beams resulting in more spacious floorplates, which can be built to greater heights. The result will be cleaner, elegant towers that will fight pollution rather than cause it.

DIALOG spokespersons Craig Applegath (architect and founding principal of the Toronto studio), Thomas Wu (structural engineer and principal), and Daria Khachi (structural engineer and principal) shared their insights with Construction Canada on this prototype.

What are your next steps for this prototype design?

Wu: The design of HTFS has been peer-reviewed by independent engineers from two different DIALOG studios. Full-scale structural testing on short- and long-term loading was planned for mid-2020. However, due to COVID-19, this task was put on temporary hold and is currently expected to resume full-scale testing in 2021.

Full-scale fire testing is also being considered. Currently there is no control fire chamber that can house a 12-m (39-ft) cross-laminated timber (CLT) panel. Fire testing capabilities and options are being investigated, Wu added. All testing will be done under University of British Columbia[3]’s (UBC’s) supervision.

Applegath: We will also be looking for potential developer partners around the world who would be interested in turning the prototype into a real building. We will continue to work with our collaborative partners—EllisDon[4], RWDI[5], Morgan Solar[6], and Pond Technologies[7]—to explore how we might implement these design strategies in other building projects. We already have developers talking to us about how to use our hybrid timber design strategies in mid-rise buildings.

One of the goals of this prototype is to help demonstrate people can construct buildings that positively impact human and environmental well-being while changing skylines around the world. How will it do that?

Applegath: The Earth is in trouble! We need to cut global carbon emissions by 45 per cent by 2030 to avoid the worst effects of climate change, and buildings and construction currently account for some 39 per cent of energy-related carbon emissions.

We started with the question, “How can we maximize the overall use of sustainably harvested wood in high-rise construction in the most cost efficient, energy efficient, and elegant manner and create a zero-carbon building?” This design prototype demonstrates the path forward to making more sustainable super-tall structures.

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In what ways can this prototype aide architects, engineers, and planners slow down climate change, address global health crises, and improve the well-being of communities and the environment?

Applegath: We must all play a major role in addressing climate change and design, approving and building cleaner, healthier buildings. We designed this building concept not only to show what we can do as architects, engineers, interior designers, and landscape architects, but also to highlight what we must do in the future to meet our goals.

The technology we are showing in this prototype is not a “nice-to-have” but we think, going forward, a “must-have” if we are going to come to grips with the realities of climate change. For example, the use of an algae bioreactor as a way of sequestering the carbon dioxide (CO₂) produced by burning natural gas to make heat and power is a hugely innovative made-in-Canada technology by Pond Technologies in Markham, Ont.

How does the prototype HTFS help meet a project’s sustainability goals?

Applegath and Khachi: Our patent-pending HTFS, with post-tensioned steel tendon in the CLT panels will allow for a 12-m, column-free span where standard CLT only spans approximately ¾ of that distance. As floor plates occupy approximately 70 per cent of building material in high-rises, our HTFS will maximize the overall use of sustainably harvested wood in high-rise construction.

Another sustainable system we designed includes the use of photovoltaics (PV). They would be deployed on the building façades, converting sunlight to energy for the facility.

Lastly, we would use a Canadian-made algae bioreactor to pull the carbon out of the boiler system and the co-generation plant.

Please provide more information on how this system allows the building of taller hybrid timber towers.

Wu: The high tensile steel cables encased in concrete bands embedded into CLT panels allows the HTFS to span an extra length, resulting in more spacious floor space. The HTFS is a prefabricated panel helping reduce onsite construction time. The non-combustible concrete band within the prefabricated panel provides the necessary fire safety. With these unique features, HTFS could be deployed in buildings of any and all heights. To seek patent protection internationally, DIALOG has filed an International Patent Application under the Patent Co-operation Treaty, applicable in over 150 countries.

What do you hope to achieve once this prototype design is adopted by AEC professionals?

Applegath, Wu, and Khachi: Our objective was to bring all of these innovations together in a way that could demonstrate the best method to create a zero-carbon building that can climb to great heights, scaling up our capacity for larger, hybrid timber, zero-carbon buildings.

We would like to thank the people and firms that collaborated in developing this prototype. EllisDon played a very important role in exploring and proving both the construction logistics and the costing of the HTFS. RWDI provided guidance and insight on how to best shape the building to deal with wind loading. Morgan Solar contributed their expertise in building envelope-integrated PV, and helped us model the power that could be generated. Pond Technologies worked with our mechanical and electrical teams to develop the CO₂ sequestration strategy that will allow this building to generate heat and power from natural gas without emitting carbon dioxide.

Source URL: https://www.constructioncanada.net/dialog-develops-system-to-build-105-storey-hybrid-timber-towers/

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