Decent housing in the developing world: Reducing life-cycle energy requirements

Developing countries face a crisis of deteriorating and unsafe human settlements conditions. Few studies examine the resources and energy required to provide everybody with decent housing. This study presents a generic methodology for the estimation of Life Cycle Energy (LCE) requirements to meet the housing gap and provide basic comfort to everybody in a developing country, based on standards of safety, durability and indoor temperature and humidity limits. The methodology includes the operationalization of this decent housing standard into materials and equipment; development of appropriate building archetypes; calculation of embodied and operating energy using a building simulation model; a parametric analysis to investigate the range of uncertainty in LCE and the attribution to different contextual conditions and energy savings measures. Results for the test case India showed that LCE of decent housing can significantly vary depending on climatic conditions, building typology, construction materials, technical equipment for space cooling-dehumidification and user behaviour. Embodied energy accounts for 27–53% of the LCE, depending on the building type and climate. LCE savings up to −44% can be achieved by implementing low embodied energy materials, building envelope insulation, ceiling fans usage and improved energy efficiency of air-conditioning systems

Energy requirements for decent living in India, Brazil and South Africa

For over 30 years, researchers have tried to estimate how much energy societies require to provide for everyone’s basic needs. This question gains importance with climate change, because global scenarios of climate stabilization assume strong reductions in energy demand growth in developing countries. Here, we estimate bottom-up the energy embodied in the material underpinnings of decent living standards for India, Brazil and South Africa. We find that our estimates fall within these countries’ energy demand projections in global scenarios of climate stabilization at 2 °C, but to different extents. Further, national policies that encourage public transportation and sustainable housing construction will be critical to reduce these energy needs. The results of this study offer a benchmark to compare countries’ mitigation efforts and technology transfer arrangements to assess the extent to which they address development priorities in an equitable manner

A spatio-temporal life cycle assessment framework for building renovation scenarios at the urban scale

Reducing the energy consumption of buildings is a priority for carbon emissions mitigation in urban areas. Building stock energy models have been developed to support decisions of public authorities in renovation strategies. However, the burdens of renovation interventions and their temporal distribution are mostly overlooked, leading to potential overestimation of environmental benefits. Life Cycle Assessment (LCA) provides a holistic estimation of environmental impacts, but further developments are needed to correctly consider spatio-temporal aspects. We propose a spatio-temporal LCA framework to assess renovation scenarios of urban housing stocks, integrating: 1) a geospatial building-by-building stock model, 2) energy demand modelling, 3) product-based LCA, and 4) a scenario generator. Temporal aspects are considered both in the lifecycle inventory and the lifecycle impact assessment phases, by accounting for the evolution of the existing housing stock and applying time-adjusted carbon footprint calculation. We apply the framework for the carbon footprint assessment of housing renovation in Esch-sur-Alzette (Luxembourg). Results show that the renovation stage represents 4%–16% of the carbon footprint in the residual service life of existing buildings, respectively after conventional or advanced renovations. Under current renovation rates, the carbon footprint reduction would be limited to 3–4% by 2030. Pushing renovation rates to 3%, enables carbon reductions up to 28% by 2030 when combined with advanced renovations. Carbon reductions in the operational stage of buildings are offset by 8–9% due to the impacts of renovation. Using time-adjusted emissions results in higher weight for the renovation stage and slightly lower benefits for renovation

Global residential scenarios towards low energy and material demands

Transition to low energy and material demand (LEMD) for buildings is key to reach climate change mitigation and sustainability targets but will require unprecedent technological and social transformations. Scenarios addressing LEMD transformations for the global building sector are still largely unexplored. In this study, we assess global residential energy and material demands until 2050 for three alternative sustainable development pathways (SDPs): Economy-driven innovation (EI), driven by technology and energy efficiency; Resilient communities (RC), a post-growth scenario centred around local communities and behavioural change; and Managing the global commons (MC), with strong global institutions and high electrification. We use the bottom-up framework MESSAGEix-Buildings, soft-linked to the integrated assessment model MESSAGEix-GLOBIOM, to model the three SDPs for the global residential sector. We show that the RC scenario entails the highest potential towards reducing energy and material demand driven by behavioural change. The EI and MC scenarios are characterized by relatively higher energy and material demand levels and might require additional efforts on the supply-side to reduce total building-related operational and construction greenhouse gases emissions. This study can support decision making on strategies towards sustainability and zero-energy and emission targets in the buildings sector

Applying LCA to Estimate Development Energy Needs: The Cases of India and Brazil

This paper illustrates the use of life cycle assessment (LCA) methods to link human wellbeing to resource consumption. Based on a previously developed framework of the material requirements for human well-being, we use LCA and Input-Output (I/O) analysis, as appropriate, to estimate the life-cycle energy needed to meet the gap in living standards in two emerging economies, India and Brazil. We illustrate the relative contribution of different living standards components to energy requirements, as well as the uncertainty and trade-offs between upfront and long-term operating energy costs, and how these factors differ in the two countries. This analysis provides insights on how LCA analysis can be used to inform energy planning and its links to development goals

Improving the SDG energy poverty targets: residential cooling needs in the Global South

With growing health risks from rising temperatures in the Global South, the lack of essential indoor cooling is increasingly seen as a dimension of energy poverty and human well-being. Air conditioning (AC) is expected to increase significantly with rising incomes, but it is likely that many who need AC will not have it. We estimate the current location and extent of populations potentially exposed to heat stress in the Global South. We apply a variable degree days (VDD) method on a global grid to estimate the energy demand required to meet these cooling needs, accounting for spatially explicit climate, housing types, access to electricity and AC ownership. Our results show large gaps in access to essential space cooling, especially in India, South-East Asia and sub-Saharan Africa. Between 1.8 to 4.1 billion, depending on the required indoor temperatures and days of exposure, may need AC to avoid heat related stresses under current climate and socio-economic conditions. This number far exceeds the energy poverty gap indicated by the Sustainable Development Goal for electricity access (SDG7). Covering this cooling gap would entail a median energy demand growth of 14% of current global residential electricity consumption, primarily for AC. Solutions beyond improved AC efficiency, such as passive building and city design, innovative cooling technologies, and parsimonious use of AC will be needed to ensure essential cooling for all with minimized environmental damage. Meeting the essential cooling gap, as estimated by this study, can have important interactions with achieving several of the SDGs

A Future Outlook of Narratives for the Built Environment in Japan

The evolution of long-term sustainable societies is closely connected to the transformation of the physical built environment in which those societies operate. In this paper, we present a comprehensive set of narratives for the built environment in Japan, consistent with the shared socio-economic pathways (SSPs) framework, to assess the future evolution of the adaptation and mitigation challenges. We focus on the linkage between sustainability factors and human living environments including urban form, buildings, and basic infrastructures. We introduce a new, sixth narrative to the SSPs, an alternative interpretation of SSP1. Whereas the original SSP1 assumes high societal and environmental sustainability combined with relatively high economic growth, the SSP1 variant does not highly rely on economic growth and is oriented towards a lower and more locally oriented consumption lifestyle. Nature-based solutions are integrated and examined in the new SSP1 narrative, which is aligned with the adaptation to the digital era with freedom of location. Recent global crises such as climate change and the COVID-19 pandemic may accelerate the transformation of societies. Therefore, this study attempts to imply the benefits and trade-offs of alternative pathways for the built environment

Global scenarios of access to basic residential cooling and adaptation to heat stress

Heat stress is a growing concern affecting health and well-being of populations worldwide. Air-conditioning (AC) can provide relief from high temperatures, but can entail high electricity demand and emissions. Future access to basic cooling is not only key for heat stress adaptation, but it also has important linkages with climate change mitigation and sustainable development goals. We assess the evolution of the global residential “cooling gap” -the extent of population lacking access to basic cooling where needed -for the Shared Socioeconomic Pathways SSP1-3, and estimate minimum energy required for bridging this gap for the global South