The case for adaptive decarbonisation
Overview
“Developers don’t like net-zero buildings because they are more expensive to build.”
Cost, or even perceived cost, is a barrier to the uptake of decarbonisation-focused design solutions working towards a net zero building [1]. The current market is one where ‘first cost’ can dominate the decision-making basis to the detriment of design quality and value. Typically, single purpose or ‘siloed’ solutions prevail within the delivery of net zero buildings. The time is ripe for changing the narrative around net zero buildings incorporating climate resilience to add value and encourage greater uptake of net zero solutions.
The narrative would be changed by incorporating climate change adaptation benefits as an integral part of net zero solutions by design rather than as an unquantified consequence. The holistic ideal of integration was put forward as a primary consideration within the IPCC’s 2023 Climate Change report [2] where it states the following:
C.1 Climate change is a threat to human well-being and planetary health (very high confidence). There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all (very high confidence). Climate resilient development integrates adaptation and mitigation to advance sustainable development for all, and is enabled by increased international cooperation including improved access to adequate financial resources, particularly for vulnerable regions, sectors and groups, and inclusive governance and coordinated policies (high confidence). The choices and actions implemented in this decade will have impacts now and for thousands of years (high confidence).
The urgency is there. The need to collaborate outside our normal circles and finance it is there. It is proposed that adaptive decarbonisation would help to drive the built environment response.
Context
Net zero buildings are part of a much wider climate change mitigation (decarbonisation) agenda across multiple industries and products. There are many instances of decarbonisation and adaptation being considered completely separately without guidance on how they might interact or be interdependent. For example, the decarbonisation calculation methodologies and targeting for (new) buildings are now quite well defined [3, 4] but the associated documentation pays little regard to climate change adaptation. Likewise, the UK 5-year National Adaptation Plan [5] pays little regard to decarbonisation. A potential driver of this separation, besides the challenges associated with making the connections, is that decarbonisation (climate change mitigation) is prescribed in Paris Agreement Article 4 and adaptation is prescribed in Paris Agreement Article 7 [6]. Some publications, such as the Climate Change Committee’s “Adaptation and Decarbonisation” report [7], do start to discuss potential co-benefits and trade-offs with advice on delivery of the joint approach but much more detail is needed in support of industry-wide adoption.
One of the challenges will be to work across disciplines and ensure strategies and, therefore, policies are joined up. For example, the environmental strategic plan for air quality in London [8] is completely dominated by transportation whereas there are separate guidelines for using green infrastructure to improve air quality [9]. This field of study was not even mentioned within the strategic plan for air quality.
There is a growing evidence base for applying different adaptation solutions in the built environment but little clarity or guidance is given on full value beyond first cost and qualitative co-benefits. Full value might extend beyond typical environmental considerations (e.g. thermal comfort) to health, wellbeing, productivity and asset or rental value. There is currently, therefore, a disconnect or separation and lack of understanding on how holistic adaptation-decarbonisation solutions might improve climate resilience whilst de-risking investment and reducing costs, i.e. the cost-benefit analysis is severely limited which could lead to poor decision-making. There are many, many potential co-benefits, quantifiable now but excluded from the design response. The insurance industry, for example, is having an increased focus on climate-related risks and provision of policies with reduced costs for claims with identified adaptation measures [10].
Consider a two-circle Venn Diagram of mitigation and adaptation (see Figure 1). The interception between the two, adaptive decarbonisation, would change in size (number and type of design elements) between different developments. Adaptive decarbonisation is a combination of adaptation and decarbonisation strategies to reduce the effects of climate change. Adaptation benefits are immediate and local. Mitigation benefits are (very) long term and global.
Fig.1: Optimal, high-value solutions include adaptive decarbonisation by design.
It is proposed that adaptive decarbonisation should be considered for construction design and planning. Adaptation plans may be staged to provide additional flexibility. All decarbonisation design solutions could be split into ‘adaptive’ and ‘non-adaptive’ options. Highly adaptive decarbonisation design solutions will result in improved climate resilience. When applied across buildings and infrastructure, it should be noted that ‘infrastructure’ has two contexts: one of three sectors within the construction industry including buildings and industrial; and also systems and services such as green-blue-grey infrastructure [11] acting with environmental coupling [12].
Exemplar cases catching full value are needed as part of a library of potential adaptive decarbonisation design solutions. There is a well-developed and expanding evidence base on blue-green / nature-based solutions delivering improved climate resilience within a systematic, quantifiable framework which utilises the full range of ecosystem services [13]. For example, as a decarbonisation measure, the shading of four trees can save 25% of the energy needed for cooling a building. In doing so, they offset about 3 to 5 times more carbon than a tree in a forest. In terms of adaptation, a tree can moderate against urban heat island effect (via both shading and evaporative cooling), storm water flood risk, noise and air pollution while acting as a wind barrier. Through improving the urban microclimate, building massing, indoor comfort, energy consumption and outdoor environment quality can be positively influenced. The blue-green systems approach has a critical role to play in enabling the retrofit sector to meet its sustainability and environmental targets and obligations.
Commentary
Planetary health is poor and declining rapidly. We are, to a large extent, reacting to events around us. Have we broken the jet stream? [14] Are we “dramatically underestimating” the extreme events coming our way? We are already witnessing more frequent slow-moving rain storms and longer lasting heatwaves in Europe and North America. A rapid and ‘wicked’ response to the urban emergency [15], generating sufficient climate resilience and readiness whilst mitigating for an uncertain future, is needed.
Decision-making with an understanding of full co-benefits ideally needs to be holistic in nature covering many traditional issues such as the thermal and air quality environment but also extending to considerations such as health, wellbeing, productivity and asset or rental value. A holistic approach assessing adaptive decarbonisation solutions should have wide appeal across many stakeholders. It needs to be delivered at scale and pace.
Although more R&D, such as quantifying the ROI of adaptive decarbonisation and modelling long-term benefits, is needed to demonstrate full value and find optimal balances in new design and retrofit buildings, the narrative could be changed quite quickly in support of this need. In a world of digital innovation, making better decisions including adaptive decarbonisation thinking will be challenging but possible in the near term.
This opinion piece proposes a change in the narrative for net zero buildings to promote uptake via identifying added value beyond energy efficiencies and clarifying mitigation benefits which may be considered somewhat abstract at times. Through improving climate resilience, uncertainty in many areas, such as related to investments and future energy costs, could also be reduced through the adoption of adaptive decarbonisation. By focusing on the commercial angle when developing adaptive decarbonisation policies and guidance, design performance, more stringent compliance targeting, planning direction and regulations could be positively influenced, amongst other things, whilst improving climate resilience.
The opinion was formed when the author attended a series of workshops followed by a UKUEQ meeting where the first draft was reviewed. The workshops were part of an initiative ‘Policy advice on decarbonisation and adaptation of buildings and infrastructure for improving climate resilience in the UK and China’ – more information on the CIBSE website [16]. This initiative, led by Prof Tim Broyd (UCL) and Prof Runming Yao (Chongqing University) also partnered with engineering institutions (ICE and CIBSE), will report in the coming months. UKUEQ and CIBSE Resilient Cities Group could play a pivotal role in supporting the development of some elements within this proposal as part of a wider collaboration between the engineering institutions, academia and industry within the UK and internationally.
References
1. UKGBC (2023). “Building the Case for Net Zero: A feasibility study into the design, delivery and cost of new net zero carbon buildings.” (Link)
2. IPCC (2023). “Climate Change 2023 Synthesis Report: Summary for Policymakers”. (Link)
3. UKNZCBS (2024). “UK Net Zero Carbon Building Standard (Pilot Version).” (Link)
4. LETI (2020). “Climate emergency design guide.” (Link)
5. UK Government (2024). “Third National Adaptation Programme (NAP3).” (Link)
6. United Nations (2015). “Paris Agreement.” (Link)
7. Climate Change Committee (2023). “Adaptation and Decarbonisation.” (Link)
8. Mayor of London (2018). “London environment strategy.” (Link)
9. Mayor of London (2019). “Using green infrastructure to protect people from air pollution).” (Link)
10. Deloitte (2019). “Climate risk: Regulators sharpen their focus.” (Link)
11. Kumar P., Corada K., Debele S. E., et al., (2024). Air pollution abatement from Green-Blue-Grey infrastructure. The Innovation Geoscience 2(4):100100 (Link)
12. Breathing City: Future Urban Ventilation Network (2021+). “Theme 1: Coupled indoor-outdoor environments.” (Link)
13. Imperial College London (2017). “Blue Green Solutions. A Systems Approach to Sustainable, Resilient and Cost-Efficient Urban Development.” (Link)
14. New Scientist (2025). “Have we broken the jet stream?”, 18th January. (Link)
15. UKUEQ (2024). “White Papers: The Urban Emergency.” (Link)