COP26: Sufficiency Should be First

  • Posted on: 3 April 2022
  • By: Yamina SAHEB

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.

The direct, indirect, and embodied CO2 emissions from the global building stock were above 14 Gt by 2020 (IEA 2021). This is almost double of 1990 emissions from buildings. Yet during the last three decades, there has been a worldwide acceleration of the adoption of building energy policies. The collective failure in significantly curbing emissions from buildings raises questions about whether the present approach to climate change mitigation policies is adequate and effective. Efficiency improvements, combined with the slow adoption of renewable energy and minor behavioural changes, are insufficient to deliver on the 1.5°C target.

Sufficiency is a set of policy measures and daily practices which avoid the demand for energy, materials, land, water, and other natural resources, while delivering wellbeing for all within planetary boundaries. Sufficiency bridges the inequality gap by setting clear consumption limits to ensure a fair access to space and resources. There are two sets of limits for sufficiency: an upper and lower boundary. The upper limit of sufficiency is the remaining carbon budget with its normative target for distributional equity. The lower limit of sufficiency is the provision of decent living standard’s requirements. A decent living standard being a set of essential material preconditions for human wellbeing which includes housing, nutrition, basic amenities, health care, transportation, information, education, and public space (Rao et al. 2019; Rao & Baer 2012; Rao & Min 2018). In contrast to efficiency, which is about doing more with less in relative terms without considering planetary boundaries, sufficiency is about consuming less in absolute terms and within the biophysical limits of the planet (Princen 2003; Rees 2021). Sufficiency targets the needs for human wellbeing while efficiency satisfies human wants by providing more commodities.

Applying sufficiency principles to buildings requires i) optimising the use of buildings, ii) repurposing unused existing ones, iii) prioritising multi-family homes over single-family buildings and iv) adjusting the size of buildings to the evolving needs of households by downsizing dwellings (Figure 1) (Sandberg 2018; Stephan et al. 2013; Duffy 2009; Fuller & Crawford 2011; Wilson & Boehland 2005; McKinlay et al. 2019; Sandberg 2018; Huebner & Shipworth 2017; Ellsworth-Krebs 2020; Berrill et al. 2021).

Cohousing strategies, such as senior cooperative housing, communities and eco-villages are among the existing solutions to downsize dwellings (Kuhnhenn et al. 2020). In practice this leads to reducing the per capita floor area by providing users, in both new and existing buildings, with a shared space (i.e. for laundry, offices, guest rooms and dining rooms) to complement their private space. As a consequence, the consumption of resources including energy, materials, water and electricity is reduced leading to a reduction of both embodied and operational emissions (Klocker et al. 2012; Klocker 2017; Goldstein et al. 2020; Duffy 2009; Heinonen & Junnila 2014; Berrill & Hertwich 2021). Less space will also result in less appliances and equipment and alter preferences towards smaller ones (Aro 2020). Beyond emissions reduction, cohousing limits loneliness of elderly people and single parents (Riedy et al. 2019; Wankiewicz 2015).

Sufficiency measures are non-energy policies. Progressive property taxes based on a cap in the per-capita floor area are also needed to adapt the size of dwellings to households’ needs (Murphy 2015). Local authorities have an important role to play in the metamorphosis of buildings by increasing the share of communal spaces (Williams 2008; Marckmann et al. 2012) through urban planning and land use policies (Duffy 2009; Newton et al. 2017). This can result in inter-generational cohousing and interactions between people with different social backgrounds (Lietaert 2010; Williams 2008).

In order to realise the full decarbonisation potential of the building stock, the design of climate mitigation policies must address the urgent metamorphosis of the global building stock by using the sufficiency, efficiency, and renewable (SER) framework (Figure 2). The first step towards this policy change is to provide policymakers with estimates of the sufficiency potential. Unfortunately, despite the growing literature on the crucial role of sufficiency in curbing emissions, most of the global scenarios aiming at 1.5°C target do not include sufficiency assumptions. On the contrary, these scenarios assume a linear increase of the per-capita floor area driven by affluence. Grubler et al. (2018), Millward-Hopkins et al. (2020) and Kuhnhenn et al. (2020) are among the few researchers working on global scenarios involving a cap in the per-capita floor area and a convergence between the Global North and South in the access to a decent living standard for all. The usual modelling methodologies lead to small tweaks to business-as-usual policies, which delay climate action. Overall, the unequivocal role of human activities in global warming is unlikely to be reduced unless sufficiency is made a primary principle in climate mitigation scenarios and policies.

This commentary was published for the first time, on October 10th, 2021 on


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