Commentaries

Transitioning to Zero-Carbon Buildings

What is needed to make today's buildings zero-carbon ready?

The urgency to radically reduce primary energy consumption and greenhouse gas (GHG) emissions during the life cycle of buildings is undisputed. The ultimate goal is a building stock which does not rely upon GHG emissions and compensates for any remaining emissions using effective and acknowledged measures (Lützkendorf & Frischknecht 2020). Thomas Lützkendorf (Karlsruhe Institute of Technology) and Rolf Frischknecht (Treeze Ltd) explore the implications for making buildings now that are zero-carbon-ready.

Structural Engineering and Carbon Footprints of CLT Buildings

Cross-laminated timber is a promising low-carbon structural solution. Research into its service life will create confidence and improve its competitiveness.

Ambrose Dodoo, Michael Dorn, Anders Olsson, Thomas K. Bader (Linnaeus University, Sweden) explain the potential of cross-laminated timber (CLT). This relatively new building technology makes it possible to construct tall wood-frame multi-storey buildings. However, the current generation of CLT-based buildings have yet to reach mid-service life. Accordingly, CLT is a subject of growing research to address open issues related to material efficiency, construction and connections, long-term structural performance and life cycle climate impacts. Efficient structural engineering design and solutions present opportunities to reduce the carbon footprint of CLT buildings.

Housing Adaptability: Some Past Lessons

Past research on housing is still relevant to today's research and policy agendas.

The issues of how housing can be adaptable are not new.  Construction historian Andrew Rabeneck reflects on research and practice from the 1970s that should be included in current conversations. Several different strategies exist: Limited Flexibility, Full Flexibililty, Build On (at a later date), Build In (at a later date), Adaptability (through the provision of extra space). One of the simplest and least cost options is the enhanced space provision i.e. an increase in room areas of up to 10% and looseness of fit - allowing 'occupant choice through ambiguity', with minimum predetermination of patterns of use.

COP26 & Beyond: What Role for Cities?

Were the needs and demands of cities and local governments marginalised in their roles and representation at COP26?

The 26^th UNFCCC Conference of Parties (COP26) in Glasgow represented a decisive moment in history. Five years after Paris, it was a moment of reckoning - had countries delivered on their promises? It was also the last chance for political leaders to raise GHG reduction targets to prevent global warming above 1.5 ^oC. Linda Westman (University of Sheffield) reflects on COP26 and the prospects for cities and local governments.

Why Building Regulations Must Incorporate Embodied Carbon

By Harpa Birgisdóttir (Aalborg University Copenhagen, DK)

Building regulations are important drivers for change. They have been focused on reducing the operational energy in buildings. This is now changing in some countries as evidence shows the significant amount of embodied emissions in construction materials. Additional new requirements are setting targets for embodied carbon in buildings and whole-life carbon assessments in order to decarbonise the built environment. Regulations are being implemented in Netherlands, France and Denmark, and planned in Finland and Sweden.

COP-26: A Commitment to Regulate Embodied Carbon

By Jane Anderson (ConstructionLCA, UK)

Although COP26 is focused on actions by state governments, their commitments are often underpinned by industry. The complexity of embodied carbon in buildings depends on regulation and standards, manufacturer compliance, professional engagement and clear methods / data. We must raise embodied carbon literacy and capabilities across the construction industry to expedite readiness for regulation. Several steps are required and some are already underway.

COP-26: Engaging Built Environment Professionals to Support Climate Justice

By Sonja Klinsky (Arizona State University, US) and Anna Mavrogianni (University College London, UK)

COP26 provides an opportunity to reflect on how the built environment community can facilitate deeper efforts towards adequate climate justice actions. Although the focus during COP26 will be on state governments, their commitments depend on consistent efforts pursued by non-state actors. Climate justice requires commitment from the built environment community who are obliged to act in the public interest. Opportunities are suggested for key actors that are well-placed to contribute to these efforts: universities and higher education, professional associations and local authorities.

COP-26: Make Nature-Based Solutions a Top Adaptation Priority

By Timon McPhearson (The New School, US)

Natural infrastructure is a critical urban infrastructure that provides fundamental and irreplaceable services for human health, wellbeing, and livelihoods. Urban development must quickly shift away from the dominant 20^th century model that exacerbates hazards and risks by paving over urban ecological infrastructure. Firm commitments at COP-26 are needed to radically increase investments in nature-based solutions in cities: restoring, conserving and investing in green and blue infrastructure assets. This will reduce the impacts of climate change as part of an adaptation strategy and also improve wellbeing.

Cities as Climate Saviours? Political Strategy Ahead of COP-26

By Linda K. Westman (University of Sheffield, UK)

Will cities play a key role at COP26 in Glasgow? This commentary examines three arguments about the importance of cities in delivering effective global climate action. Each argument is developed in relation to the negotiating position and political strategy of the UNFCCC Local Government and Municipal Authority (LGMA) constituency (LGMA, 2019).

Healing Cities: Toward Urban Climate Justice & Slum Health

By Jason Corburn (University of California, Berkeley, US)

The overlapping crises of climate change, COVID-19, and persistent social inequities are acutely felt in cities, particularly among the poor and already vulnerable. Urban climate justice demands a focused strategy to support the healing of these vulnerable communities while also creating new opportunities for them to co-lead more equitable climate resiliency strategies. COP-26 must address 'healing cities for climate justice;' or the need for urgent investments with (not on or for) already vulnerable people and places in order to eliminate existing suffering and urban traumas, while also planning for future prosperity.

Why Digital Building Passports Are Vital for Change

By Thomas Lützkendorf (Karlsruhe Institute of Technology, DE), Ursula Hartenberger (PathTo2050, BE), York Ostermeyer (Chalmers U, SE)

COP-26 is about showcasing action and replicable, practical solutions that will accelerate market transformation. Climate action must become incorporated into the regular activities of the construction and real estate sectors. The way to achieve this is to incentivise a systematic and transparent approach to building-related information which can accelerate and reward stakeholder action. The building passport can accomplish this by creating a "living document". In first instance, governments should set an example by making building passports mandatory for public buildings and then consecutively roll it out across other building typologies and market segments.

Adapt or Retreat? Developing a Long-Term Regional Planning Strategy

By Ellen van Bueren (Delft University of Technology, NL)

The delegates at COP-26 should now fully direct their attention to creating agreements and action plans. This creates a momentum to start planning our urban futures with a long-term perspective, in tune with the changing climate. The emphasis on adaptation is not always an appropriate option as it has unintended consequences which compound risks and can lead to a downward spiral of neighbourhoods and cities. A public debate is needed to develop clarity on when and where adaptation or managed retreat are appropriate. We need to ask: how can city regions develop in a resilient way, what assets should be preserved, at what costs and how do we protect vulnerable citizens?

Climate Adaptation in Cities: Planning for Heat Vulnerability

By Rohinton Emmanuel (Glasgow Caledonian University, UK)

Urban warming creates a 'double jeopardy' on a majority of humans (urban heat island and global warming). Sufficient information exists to identify where local action is most needed to protect those who are most vulnerable. As a matter of urgency, COP-26, national governments and local authorities need to address heat vulnerability by identifying vulnerable areas and implementing changes in planning practices.

Adapting our Cities and Urban Planning to Climate Change: Microclimates

By Michael Donn (Victoria University Wellington, NZ)

The complex and dynamic interactions between 3-D built form and the local environment must be accounted for in planning decisions to create pleasant, resilience microclimates for now and the future. Present planning procedures are over-simplistic and unsuitable. New approaches are suggested.

Reconcile Healthy Indoor Environments and Climate Mitigation

By Christhina Candido, Rebecca Bentley and Samin Marzban (U Melbourne, AU)

Buildings are often referred to as a "second skin", providing sheltered infrastructure for working, playing, learning and living. People place trust in buildings to protect them and to provide safe indoor environments. Lessons from COVID-19 and recent extreme weather events are pertinent to COP-26, linking public health to the need for both mitigation and adaptation.

Fast-Growing Bio-Based Materials Can Heal the World

By Guillaume Habert (ETH Zurich, CH)

The construction industry faces many pressures including: to deliver both rapid urbanization and a steep decarbonization of the materials that it uses. Radical reductions in GHG emissions are needed by 2030, so the construction industry must drastically reduce its operational and embodied emissions within a short time frame. It is imperative to start implementing realistic solutions straightaway. Fast growing bio-based agricultural materials can store carbon in less than a decade and provide a realistic solution for building materials.  Positive change can be created quickly by creating both supply push (agriculture) and demand pull (public procurement and regulatory demand).

Climate Justice and English Dwellings

By Jonathon Taylor (Tampere U, FI), Lauren Ferguson* , Anna Mavrogianni* & Clare Heaviside* (*University College London, UK)

The changing climate is expected to have a disproportionate impact on disadvantaged groups worldwide, due to greater exposure - and vulnerability - to various climate hazards. Urgent actions are needed to provide equity through not only providing mitigation measures, but also adapting homes that are most vulnerable to climate effects.

India's Role in Sub-Saharan Africa: COP-26 Expectations

By Ankit Kumar (U of Sheffield, UK), Joshua Kirshner (U of York, UK), Lata Narayanaswamy (U of Leeds, UK) and Enora Robin (U of Sheffield, UK)

In the past decade, growing attention has focused on South-South cooperation in climate change mitigation, energy transitions and infrastructure development, especially on the increasing role of BRICS countries in sub-Saharan Africa (SSA). The questions of appropriate development - reducing the dependencies on carbon-based energy (and mineral consumption) for development - are highly pertinent to climate justice and an equity in partnership.

COP26: Sufficiency Should be First

By Yamina Saheb (Lausanne University, CH)

Avoiding the climate emergency requires going beyond the current set of policy measures. Instead, the concept of sufficiency needs to be adapted and applied to today's environmental and societal challenges. This would provide clear metrics that are equitable and within the Earth's ecological limits. The application of sufficiency to policies for building stock would provide a decent living standard for all and have a significant impact on limiting global warming.

What China's Carbon Neutrality Means for its Building Stock

By Wei Yang and Jie Li (Tianjin University, CN)

China's pledge to become carbon neutral will have profound effects on its existing and new buildings. Scalable scenarios from national to district levels have been created to begin a process of assessing and apportioning carbon budgets.  A range of new economic, social and technical measures will be needed to achieve this radical transformation.