Claudiu Silvestru, 27.11.2025
The construction sector sits at the heart of global sustainability debates. It is a major driver of resource consumption, energy use, and emissions, while at the same time providing essential infrastructure for housing and economic activity. In discussions around sustainability, two paradigms dominate: efficiency and sufficiency. Efficiency aims to optimise existing processes, making them more resource- and energy-effective without questioning fundamental demand. Sufficiency, by contrast, calls for reducing overall demand, rethinking needs, and shifting cultural and economic practices toward “enough.” While efficiency dominates in Western sustainability discourse, sufficiency often remains marginal despite its transformative potential.
This essay explores the difference between efficiency and sufficiency across several dimensions of the construction sector, including digital tools, material cycles, financing and business models, labour markets, user expectations, global perspectives, and future scenarios.
Technology
Technological innovation is a core driver of efficiency in the construction sector. Digitalisation, circular economy approaches, and advanced building systems are celebrated for reducing energy use and material flows per unit of space. From a sufficiency perspective, however, the same tools can be redirected to question demand, extend lifespans, and prioritise reuse over replacement. The key difference lies not in the technology itself, but in the goals pursued.
Digitalisation and BIM
| Building Information Modelling (BIM), particularly in its more advanced forms such as Active BIM (integrating real-time operational data), exemplifies the efficiency paradigm. BIM enables more accurate planning, reduces errors, optimises material quantities, and supports energy-efficient building operation. Active BIM goes further by feeding data back into building management systems, allowing heating, cooling, and maintenance schedules to adjust dynamically. | From a sufficiency perspective, the same tools can be used not only to optimise but also to question demand. Active BIM can track actual space use, identify underutilised areas, and reveal opportunities for sharing or reprogramming. By highlighting synergies and minimising unused timeslots, it reduces the pressure to build new or expand existing facilities. Simulations of adaptive reuse, smaller footprints, or shared facilities can demonstrate how existing assets might suffice without additional construction. |
Circular Economy and Building Technologies
| The circular economy is often framed through an efficiency lens: high-tech recycling, material passports, and modular construction techniques make material recovery more effective. Similarly, advanced composites and 3D-printed components are celebrated for their performance and versatility. However recycling reduces per-unit material consumption but does not necessarily reduce overall demand. | Sufficiency emphasises reuse over recycling. Extending the life of existing buildings and components, prioritising repair, and using low-tech, bio-based, maintainable solutions reduce the need for new materials altogether. This includes extending the life of existing buildings and building parts, prioritizing repair, and embracing low-tech, bio-based, and easily maintainable solutions. Regulatory frameworks can either incentivise demolition or make reuse easier. The circular economy, from this perspective, is about “slowing the loop,” not just “closing it,” lowering turnover and absolute material demand. |
Units of Measurement
| Sustainability in the built environment is commonly measured in terms of performance per unit of building area:Energy Use Intensity (EUI) – kWh/m²·yr, measuring annual energy demand per floor area. Widely applied in building codes and certification systems, EUI links directly to design decisions such as insulation or HVAC efficiency.CO₂e/m² – greenhouse gas emissions per square metre, operational or life cycle, used for retrofit assessments and carbon benchmarking.These area-based indicators make buildings comparable regardless of size, but they do not reflect how much space is actually used or by how many people. | Sufficiency requires metrics that capture absolute demand and occupancy (Ghosh et al. 2020; Sleiman et al. 2024; IPCC 2022):Energy or emissions per person (kWh/person·yr; CO₂e/person·yr) – link environmental impacts directly to users served.Floor area per person (m²/person, m³/person) – indicates oversupply and potential for downsizing.Occupancy-normalised energy (Wh/person·h) – measures intensity of use and highlights opportunities for space-sharing.Per-person and occupancy-based measures shift the focus from how efficiently buildings operate to how they suffice to meet human needs. Active BIM and digital occupancy monitoring allow conversion of area-based metrics into sufficiency-oriented, person-based measurements, revealing opportunities to reduce absolute demand. |
Economy
The financial sector strongly supports efficiency, rewarding innovation that fits into established growth models and return expectations. Sufficiency, in contrast, requires new instruments that prioritise long-term stability, shared value, and reduced turnover. Here the divergence is stark: efficiency thrives within markets, sufficiency depends on policy and regulatory frameworks to redirect investment.
Financing Systems and Economic Models
| Efficiency approaches in financing systems reward performance improvements within existing growth models. Green bonds, ESG ratings, and tax incentives encourage investment in energy-efficient new buildings or in upgrading existing stock. While these tools accelerate innovation, they also reinforce the underlying logic of expansion and return on capital. | Sufficiency-oriented financing prioritises refurbishment over new builds, supports cooperative or community-led housing, and de-risks smaller projects that deliver social rather than purely financial returns. Value shifts from short-term capital gains to long-term usability and shared wellbeing, challenging speculative investment dominance. |
Business Models and Market Structures
| Efficiency aligns with innovation-driven models: smart management services, predictive maintenance, and constant material/system upgrades. These models depend on continual growth and frequent reinvestment. | Sufficiency disrupts turnover-based models. Companies act as stewards, maintaining and adapting stock. This challenges revenue models but offers long-term stability and resilience. |
Labor Market Implications
| Efficiency favours high-tech skills: digital modelling, advanced engineering, and complex building system management. While this concentrates opportunities in high-tech clusters, it risks excluding traditional craftsmen. | Sufficiency revitalises traditional skills: repair, refurbishment, and craftsmanship with wood, clay, or stone. It generates labour demand in deconstruction, adaptive reuse, and maintenance. Sufficiency distributes employment across local economies, anchoring jobs in areas outside high-tech hubs. |
Culture
Efficiency appeals to users, planners, and contractors by promising comfort and progress without sacrifice. Sufficiency, however, requires shifts in expectations: smaller spaces, more sharing, and cultural acceptance of “enough.” Globally, efficiency risks imposing Northern models everywhere, while sufficiency aligns more closely with diverse local practices and vernacular traditions.
Stakeholder Expectations
| Efficiency provides comfort without sacrifice: well-insulated homes, smart thermostats, and renewable heating enable familiar lifestyles at lower per-m² energy costs. Owners and contractors also prefer efficiency solutions, as they integrate relatively smoothly into established business practices. | Sufficiency demands cultural change: acceptance of smaller living spaces, shared infrastructure, and adaptive reuse. Owners must value longevity over rapid returns. Planners and contractors focus on refurbishment and reuse. The shift is from “more and better” to “enough and lasting.” |
Global and Spatial Perspectives
| Urban contexts embrace efficiency through densification, smart city concepts, and high-performance districts. The Global North exports these models globally, assuming universality. However, they risk imposing high-tech, resource-intensive systems on contexts where sufficiency is already practiced. | In rural or Global South contexts, sufficiency is not an innovation but a reality: vernacular designs, smaller footprints, and community-based housing approaches are widespread. Recognising these pathways validates low-resource, context-appropriate solutions rather than imposing high-tech efficiency. |
Adaptive Reuse and Retrofitting
Retrofitting and adaptive reuse offer a unique lens where efficiency and sufficiency intersect. Efficiency focuses on optimising the performance of existing buildings – energy, materials, and systems – while sufficiency asks whether space and resources could be reduced or repurposed, challenging the assumption that new construction is necessary.
| From an efficiency perspective, adaptive reuse and retrofitting focus on optimizing the performance of existing buildings while retaining their structure. Key strategies include:Energy optimisation: insulation upgrades, efficient HVAC/lighting, renewable integration.Digital tools: Active BIM monitors systems and occupancy to guide targeted interventions.Circular economy: recycling materials reduces per-m² resource use.Market and labour: high-tech skills and performance-guarantee contractors.Efficient adaptive reuse reduces energy use and material waste per area but does not necessarily reduce overall space or demand. | From a sufficiency perspective, adaptive reuse and retrofitting are evaluated based on whether they reduce the absolute demand for new construction and material use, rather than only improving performance per m². Important considerations include:Purpose and intensity: repurposing spaces for shared or community uses.Space and footprint: downsizing and reorganising underutilised areas.Circular economy: emphasising reuse over high-tech recycling.Market and labour: traditional trades, repair skills, small-scale interventions.User expectations: matching community needs, accepting shared spaces.Sufficient adaptive reuse may challenge expectations but produces long-term ecological and social benefits. |
Forecast 2050: Efficiency-Only vs. Sufficiency-Only
How does a biased AI forecast an efficiency-only world? And what would a sufficiency-only world look like in 2050? Imagining the world in 2050 allows a speculative exploration of the long-term consequences of exclusively following either of the pathways. Efficiency-driven futures highlight technological optimisation, high performance, and urban densification, but may perpetuate high resource demand and global inequalities. Sufficiency-driven futures emphasise reduced absolute demand, adaptive reuse, equitable distribution of space, and ecological resilience.
| Efficiency-Only World (2050) In the Global North, economies thrive on exporting high-tech efficiency solutions: modular prefabrication, digital twins, and advanced material recovery technologies. Cities are glittering showcases of “smart sustainability,” but consumption levels remain very high. Efficiency has reduced per-unit emissions, yet global resource extraction continues to rise, pushing ecological limits.The Global South has partially adopted these technologies, but unevenly. Wealthier regions integrate smart urban districts, while poorer areas struggle to afford or maintain high-tech systems. Global inequalities persist, as the North controls key technologies and resources. Climate impacts weigh heavily on less affluent regions, where efficiency solutions are insufficient to offset structural vulnerabilities. Efficiency-Only Europe (2050) Cities are dense, digitised, and highly optimised. Buildings are equipped with smart systems that minimise energy consumption: Active BIM and AI continuously adjust heating, cooling, and lighting. Urban mobility is electrified and automated, reducing local emissions. Material cycles are tightly controlled, with advanced recycling plants feeding high-tech construction industries.However, despite efficiency gains, cities continue to expand. Per capita living space has grown, driven by consumer demand and speculative investment. Rural areas face depopulation as efficiency-driven economies concentrate around metropolitan hubs. Energy and resource use per m² is lower than in 2020, but total demand remains high due to increased volumes. Europe has managed to decarbonise significantly but struggles with high resource dependency on global supply chains for rare materials, creating new geopolitical vulnerabilities. | Sufficiency-Only World (2050) The Global North has undergone profound cultural adaptation, as prosperity is no longer measured in material growth but in wellbeing and equity. Economies have reoriented toward low-growth or post-growth models. Material use is strictly limited; the average citizen consumes fewer goods but enjoys access to resilient infrastructures, public housing, and shared mobility. The construction sector is smaller but stable, centred on maintaining and adapting existing stock.The Global South experiences greater parity. Many sufficiency practices already rooted in vernacular design, community building, and low-tech solutions become global benchmarks. Knowledge flows are less one-directional: instead of importing Northern high-tech models, sufficiency encourages mutual learning across regions. Resource demand is much lower globally, reducing pressure on ecosystems and minimising climate damages. Sufficiency-Only Europe (2050) Cities are more compact and multifunctional. Living spaces are smaller, but more effectively shared and designed for flexibility. Community hubs, co-housing models, and adaptive reuse dominate urban areas, while demolition is rare. Urban expansion has slowed, with many new construction projects replaced by refurbishment and repair.Rural areas are revitalised by sufficiency-oriented policies: shorter supply chains, decentralised energy systems, and local crafts play a strong role. Migration into smaller towns has balanced population distribution, alleviating pressure on megacities. Material throughput and energy demand are dramatically reduced compared to 2025. Comfort levels are somewhat lower, but social cohesion and resilience are higher. Europe’s ecological footprint has shrunk, and dependence on global supply chains has eased, though economic growth is slower. |
Conclusion
The contrast between efficiency and sufficiency is not a competition but a matter of complementary approaches. Efficiency is politically and economically attractive: it aligns with current market logics, maintains growth and comfort, and produces measurable improvements, easily quantified using standard area-based metrics such as kWh/m² or CO₂e/m². Indeed, industry and the construction sector already prioritise efficiency because it is profitable, technologically feasible, and embedded in established business models.
Sufficiency, by contrast, challenges these same market logics. It asks deeper questions: how much space, material, and energy do we truly need, and for what purpose? Measuring sufficiency requires per-person or occupancy-based metrics (kWh/person, CO₂e/person, m²/person), which reveal absolute demand reductions rather than relative performance gains. These measures often highlight opportunities for adaptive reuse, downsizing, and shared spaces that the market alone will not prioritise, because they may limit growth or reduce turnover.
In the construction sector, this distinction affects technologies, financing systems, business models, labour markets, and cultural expectations. Efficiency will continue to be driven by market forces, but sufficiency requires strong policy intervention, regulatory frameworks, and planning incentives to ensure that reductions in absolute demand are realised. Without sufficiency, efficiency risks becoming mere optimisation within a system that remains unsustainable at its core.
Looking toward 2050, efficiency may produce smart, technologically advanced cities, but sufficiency offers resilience, equity, and ecological balance. The challenge is to weave both together: allowing innovation and optimisation to continue, while using policy, regulation, and sufficiency-oriented metrics to guide demand reductions, ensuring that the built environment truly aligns with long-term social and ecological goals.
References
Ghosh, T., L. Coscieme, S. J. Anderson, and P. C. Sutton. 2020. “Building Volume Per Capita (BVPC): A Spatially Explicit Measure of Inequality Relevant to the SDGs.” Frontiers in Sustainable Cities 2: 37. Online at: https://doi.org/10.3389/frsc.2020.00037.
IPCC. 2022. Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by P. R. Shukla, J. Skea, and R. Slade. Cambridge: Cambridge University Press.
Sleiman, S., M. Ouf, W. Luo, R. Kramer, W. Zeiler, E. Borkowski, T. Hong, Z. Nagy, and Z. Chen. 2024. “Overview of Occupant-Centric KPIs for Building Performance and Their Value to Various Building Stakeholders.” Energy & Buildings 322. Online at: https://www.sciencedirect.com/science/article/pii/S037877882400820X