Understanding the drivers of energy and material flows of cities is important for addressing global environmental challenges. Accessing, sharing, and managing energy and material resources is particularly critical for megacities, which face enormous social stresses because of their sheer size and complexity. Here we quantify the energy and material flows through the world’s 27 megacities with populations greater than 10 million people as of 2010. Collectively the resource flows through megacities are largely consistent with scaling laws established in the emerging science of cities. Correlations are established for electricity consumption, heating and industrial fuel use, ground transportation energy use, water consumption, waste generation, and steel production in terms of heating-degree-days, urban form, economic activity, and population growth. The results help identify megacities exhibiting high and low levels of consumption and those making efficient use of resources. The correlation between per capita electricity use and urbanized area per capita is shown to be a consequence of gross building floor area per capita, which is found to increase for lower-density cities. Many of the megacities are growing rapidly in population but are growing even faster in terms of gross domestic product (GDP) and energy use. In the decade from 2001–2011, electricity use and ground transportation fuel use in megacities grew at approximately half the rate of GDP growth.

This article assesses housing quality in IbejuLekki, a peripheral settlement outside Lagos metropolitan region. Using purposive sampling, 370 housing units from clusters of 16 periurban settlements constituted the sample size. Primary data was sourced through structured questionnaires, interview (with local planning personnel) and observation schedules administered through a field survey. Using Statistical Package for Social Sciences, data analysis was done using descriptive analysis to generate frequen cies and percentages on socio-economic profile, neighbourhood quality, locational quality, dwelling quality, and building materials used. Tests of correlation were conducted on the mean of variables of neighbourhood quality, locational quality and building materials, derived through recoding of variables by means of Transform statistical tool, to establish the factors influencing housing quality in the study area. The findings show a significant positive correlation between household income and housing quality. The latter is found to be influenced by respondents' socio-economic attributes, building materials, neighbourhood quality, and locational quality in the study area. It can be concluded that socio-economic characteristics, predominantly income of households, play a major role in the level of housing quality that can be accessed in the study area. It is, therefore, recommended that the state government and private developers should promote alternative building materials, in order to enhance housing affordability by the low-income group. This will reduce the spread of informal housing development. In addition, the state govern ment should align urban policy to eliminate disparity in

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Purpose Recently, frequent occurrence of fire incidences in various building types with devastating effects on human settlements have proliferated and have become of serious concern to Nigeria’s economy. Hence, there is a need to proactively address strategic weaknesses in measures directed at protecting the built environment (BE). The purpose of this paper is to examine stakeholders’ role in the frameworks on disaster risk reduction (DRR) in the context of fire hazards within Lagos metropolis. Analysis is based on findings of research carried out on vulnerability, resilience assessment and guiding principles from three recent frameworks. Design/methodology/approach Mixed research design was adopted using questionnaires and semi-structured interviews. In all, 165 BE professionals in the construction industry, state/federal emergency management and local/national government agencies were randomly selected. Findings Findings show that stakeholders believe prevention, preparedness and mitigation of disasters are the most important; however, BE professionals in the construction industry do not play active roles in the mitigation of fire risk despite wide publications on guidance for fire hazard mitigation. These stakeholders urgently need to adopt fire hazard mitigation strategies, especially in the pre-construction phase of a building’s life cycle which is identified as the most critical stage in the construction phase. Research limitations/implications The paper looked at fire occurrence in Lagos from the perspective of the BE with the view to fill knowledge gaps for adopting fire hazard mitigation strategies. Originality/value The findings brought to bear the need for stakeholders, especially BE professionals in the construction industry, to be better involved in DRR as regards fire occurrences.

This work focuses on the local alkaline wastes of Estonia where different waste streams were studied for the performance testing of the fly ash based building blocks. Fly ash from oil shale direct combustion and wood fly ash from district heating plant were considered in the applications for utilizing both CO2 and combustion residues. These types of ashes contain Ca/Mg-oxides, silicates, or other metal oxides as candidate precursor materials for CO2 mineralization. Based on the results obtained from the performance testing of all compacted and carbonated (both with model flue gas and 100%CO2) samples, it can be concluded that flue gas curing can be an effective method for direct mineral carbonation of compacted fly ash blocks. The formation of carbonate phases in compact bodies lead to an increase in compressive strength. The rate limiting impact due to the low CO2 concentration in flue gas curing was negligible on the CO2 uptake level when elevated curing pressures were applied to the fly ash based compacts.