Low-income Dwellings Research Articles

A physics-informed deep learning-based urban building thermal comfort modeling and prediction framework for identifying thermally vulnerable building stock

PurposeDue to the increasing frequency of extreme weather and densifying urban landscapes, residences are susceptible to heat-related discomfort, especially those in a naturally ventilated built environment in tropical climates. Indoor thermal comfort is thus paramount to building sustainability and improving occupants' health and well-being. However, to assess indoor thermal comfort considering the urban context, it is conventional to use questionnaire surveys and monitoring units, which are both case-centric and time-intensive. This study presents a dynamic computational thermal comfort modeling framework that can determine indoor thermal comfort at an urban scale to bridge this gap.Design/methodology/approachThe framework culminates in developing a deep learning model for predicting the accurate hourly indoor temperature of urban building stock by the coupling urban scale capabilities of environment modeling with single-building dynamic thermal simulations.FindingsUsing the framework, a surrogate model is created and verified for Dharavi, India's informal urban settlement. The results indicated that the developed surrogate model could predict the building's indoor temperature in several complex new urban scenarios with different building orientations, layouts, building-to-building distances and surrounding building heights, using five different random urban representative scenarios as the training set. The prediction accuracy was reliable, as evidenced by the mean bias error (MBE) and coefficient of (CV) root mean squared error (MSE) falling between 0 and 5%. The findings also showed that if the urban context is ignored, estimates of annual discomfort hours may be inaccurate by as much as 70%.Social implicationsThe developed computational framework could help regulators and policymakers engage in more informed and quantitative decision-making and direct efforts to enhance the thermal comfort of low-income dwellings and informal settlements.Originality/valueUp to this point, majority of literature that has been presented has concentrated on building a body of knowledge about urban-based modeling from an energy management standpoint. In contrast, this study suggests a dynamic computational thermal comfort modeling framework that takes into account the urban context of the neighborhood while examining the indoor thermal comfort of the residential building stock.

An avenue for providing the integration of distributed PV generation in low-income dwellings in Brazil

The purpose of this study is to analyze the impact on the income of families benefiting from the “Minha Casa Minha Vida” Brazilian Social Housing Program through the integration of photovoltaic (PV) generation systems into housing financing, as outlined by Law 14,620 enacted in July 2023. Given the novelty of this legislation, there is no existing database for analysis. Consequently, simulations of PV generation were carried out for the typical dwellings provided by the program across the five macro regions of Brazil. The simulation takes into account maintenance and equipment replacement costs, tariff rules, and standard adjustment rates in the country. Across all examined scenarios, the installation of residential rooftop PV systems yielded favorable outcomes, resulting in a reduction in electricity costs for the low-income population. Making provisions for a Sinking Fund in the program was identified as crucial to provide sustainability, long-term operation, maintenance and replacement. Additionally, it was observed that civil construction companies play a crucial role in popularizing the proposal. In conclusion, legislation incorporating PV generation into the national housing program represents merely the initial step toward realizing the widespread adoption of this energy generation technology in the country.

Evolving from an indirect evaporative cooling system to a radiant-capacitive heating and cooling system for low-mass buildings

The study shows the development of a novel passive cooling system parting from previous experience gathered with an Indirect Evaporative Passive Cooling System (IEPCS), originally employed in a low-income dwelling located in the hot-humid climate of Maracaibo, Venezuela. Using the design thinking approach, we optimized the original passive cooling system so as to curb some limitations observed in the IEPCS, and developed a novel passive cooling and heating system more suitable to refurbishment schemes of low-mass dwellings in tropical areas. We present comparative results from test runs in small-sized test cells for the subtropical climatic conditions of Curitiba, Brazil. The hydronic system operates with water circuits to and fro a thermal storage unit, a sky radiator/solar collector to radiant-capacitive modules indoors. Results showed that while both the roof-pond system and the radiative cooling system with indoor capacitive module provide stability to the indoor thermal environment, a somewhat greater thermal amplitude is observed in the latter, which is partly due to the difference in thermal mass between the two systems. Cooling output of the novel system was somewhat lower than that of an indirect evaporative system and dependent on atmospheric exposure conditions of the sky radiator. Heating output is given as a function of pumping duration. Cooling potential reached about 78 % of that of the roof-pond module, for test conditions with nocturnal sky radiative cooling and no water circulation from the storage tank to the interior during the day.

Optimized thermal envelope of low-income dwellings in Santiago de Chile incorporating Pinus radiata wood impregnated with phase change materials

The demand for air conditioning and heating in the construction sector has increased in about two decades, mainly because of demographic and economic growth. The result of this increase in energy consumption has been more greenhouse gas emissions (GHGs). This paper proposes a multi-objective optimization design that helps reduce heating, ventilation, and air-conditioning (HVAC) energy consumption and increases the thermal comfort levels in low-income housing. Achieving these objectives required choosing a dwelling unit that is representative of the Chilean housing stock, which was identified with the help of the National Housing Monitoring Network (ReNaM). The selected optimization variables correspond to the type of windows, type and thickness of ceiling insulation, and type of PCM-impregnated Pinus radiata wood panel, with PCM melting points between 8 and 27 °C. Subsequently, we minimized the hours of thermal discomfort and the dwelling typology's electrical consumption of heating and cooling by using the algorithm the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The main results include a reduction of up to 21.5 % in the thermal discomfort hours and a decrease of up to 80.5 % in energy consumption associated with the optimal housing typology compared to the base case. Additionally, the economic analysis indicated the payback period is 12.9 years for the Pareto solution, which presents a lower distance to the utopic point (UP).

Integrated assessment of the extreme climatic conditions, thermal performance, vulnerability, and well-being in low-income housing in the subtropical climate of Australia

Social housing stock worldwide can be characterised by poor indoor environmental quality and building thermal performance, which along with the increasing urban overheating put the low-income population at higher health risk. The dwellings’ thermal performance and the indoor environmental quality are often overlooked in the context of social housing compared to the general building stock in Australia. In the present study, the synergies between urban microclimate, indoor air temperature, housing characteristics and quality of life of residents have been investigated by employing subjective and objective assessment of indoor environmental quality in 106 low-income dwellings during the winter and summer of 2018–2019 in New South Wales. It further examines the impact of urban overheating and levels of income on indoor thermal conditions. The subjective method involved assessing the links between the type of housing in which low-income people live, energy bills, self-reported thermal sensation, health and well-being, and occupants’ behaviours. The results show that many dwellings operated outside the health and safety temperature limits for substantial periods. Indoor air temperatures reached 39.8 °C and the minimum temperature was about 5 °C. While the upper acceptability limit for indoor air temperature was 25.6 °C for 80 % satisfaction, periods of up to about 997 and 114 continuous hours above 26 °C and 32 °C were found in overheated buildings, respectively. Indoor overheating hours above 32 °C were recorded up to 238 % higher in Sydney’s western areas compared to eastern and inner suburbs. Similarly, residents in westerns suburbs and regions experience more outdoor overheating hours than those living near the eastern suburbs. This study highlights the interrelationships between ambient temperature, housing design, income, thermal comfort, energy use, and health and well-being in the context of social housing. The evidence of winter underheating and summer overheating suggests that improvements in building quality and urban heat mitigation are required to minimise the impacts of poor-performing housing and local climate.

Preface

THE 5TH HABITECHNO INTERNATIONAL CONFERENCE ADAPTIVE TECHNOLOGY FOR RESILIENT HUMAN SETTLEMENTHABITechno is a biennial international conference that focuses on creative solutions in the idea and application of modern technology for housing and settlement development, particularly for low-income dwellings in developing countries. Since 2013, the Department of Architecture, School of Architecture, Planning and Policy Development, Institut Teknologi Bandung (ITB) has organized HABITechno in conjunction with other institutions in Housing and Settlement and Building Technology in Indonesia and overseas.Regulations aimed at limiting the spread of COVID-19 have had an unprecedented impact on organizations, institutions, and individuals. The online system has started a discussion on the role of technology in assisting people in dealing with this circumstance. To help people stay informed and healthy during COVID-19 the 5th HABITechno was held on November 11th, 2021, virtually (online) with the theme is ‘Adaptive Technology for Resilient Human Settlement’.That topic is to respond to the progress of digitalization and globalization of the world in accomplishing economic competitiveness, organization, and community, especially in the human settlement sector. The goals are to critically revisit and rethink the existing and potential of such adaptive technology development by proposing a solution for sustainable development under conditions of transition in developing countries.List of Structure of Committee, Advisory Board, Steering Committee and Reviewer Board, Keynote Speaker for Webinar Series, Keynote Speaker for International Seminar - Main Event, Organizing Committee, Proceeding Committee are available in this pdf.

Climate change mitigation: thermal comfort improvement in Mediterranean social dwellings through dynamic test cells modelling

Global warming will lead to adverse consequences for human health and well-being. This research ought to determine whether passive low-cost strategies freely controlled by users (ventilation strategies, solar shadings or window operation) could be applied in low-income dwellings to meet acceptable thermal comfort to retrofit the Mediterranean social housing stock of southern Spain towards climate change. On-site measurements registered in some test cells (controlled environment with no users’ influence) were used to calibrate dynamic energy simulation models. The impact of several future periods, climate zones of southern Spain and orientations on thermal comfort was assessed. The results show that climate change triggers a more significant increase in outdoor temperatures in summer than in winter. Should ventilation be kept to minimum and blinds opened during daytime in winter, higher comfort would be achieved, with great differences between orientations and south reporting the best results. The higher the outdoor temperatures due to climate change, the higher the percentage of comfort hours (i.e. 23–68% in the present and 50–75% in 2080). In summer, natural night ventilation and blinds closed during daytime lead to the best comfort result, with negligible temperature differences between orientations. Future climate change scenarios worsen the percentage of comfort hours (i.e. 96–100% in the present, while up to 17% in 2080). Mechanical ventilation and blind aperture schedules were found to have the highest influence on overheating discomfort. Likewise, mechanical and natural ventilation schedules had the highest impact on undercooling discomfort.

Do energy subsidies affect the indoor temperature and heating energy consumption in low-income households?

As social interest in energy welfare increases, support programs and policies for fuel poverty are steadily being implemented. Energy subsidies play a significant role in improving the indoor thermal conditions affected by fuel poverty. However, various measures to reduce green-house gas emissions in the building sector are being applied. As a result, a balance between energy welfare and energy saving policies is required.This study aims to analyze the effect of an energy subsidy on improving the indoor temperature and heating energy consumption in low-income dwellings. Long-term and detailed measurements and surveys were conducted for 16 low-income households in an apartment complex in Korea (semi-cold climate). The indoor temperature and heating energy use with/without energy voucher were analyzed. In addition, the annual heating energy consumptions of all 1460 households in the same apartment complex were analyzed.The results showed that the indoor average temperature of the households receiving the energy subsidy was 24.68 °C, and the households without the energy subsidy were 22.62 °C. In addition, the indoor minimum temperature of the households receiving the energy subsidy was about 1.5 °C higher. The annual heating energy use increased by 59.9% for the older building and 26.6% for the newer building compared with those who did not receive energy subsidies. Energy vouchers have a strong influence on the indoor thermal condition and heating energy consumption of low-income dwellings. The energy subsidy policy for the low-income households needs to be re-examined in terms of energy savings and energy welfare.

Dynamic evaluation of thermal comfort scenarios in a Colombian large-scale social housing project

PurposeThis study aims to analyze the technical, environmental, economic and thermal comfort impacts of implementing passive measures and heating systems in Ciudad Verde, a large-scale social housing project located at the periphery of Bogota, Colombia.Design/methodology/approachA system dynamics (SD) model is proposed to evaluate scenarios through counterfactual experiments, including technical, environmental and economic components. Model inputs are obtained from building energy simulation models and data collected from official reports, public policy documents and construction records.FindingsResults suggest that the use of heating systems is the best choice to achieve thermal comfort conditions throughout the day. However, both the capital expenditures and CO2 emissions associated with such system make their adoption very difficult. In line with that, the use of heating systems in combination with passive measures stands out as a viable solution since their costs are affordable and their use contributes to reducing CO2 emissions.Originality/valueThe proposed model recreates the dynamics underlying social housing construction processes, the adoption of heating systems and passive measures in low-income dwellings and their corresponding impact on CO2 emissions and indoor thermal comfort conditions. The model can be employed as a support tool in the formulation of social housing policies associated with thermal comfort specifications. In this way, the model represents a first step toward incorporating thermal-related variables into the decision-making processes related to social housing planning and development.

Natural Ventilation Strategy in a Social Housing with Sub-humid Warm Climate Based on Thermal Comfort

Abstract Natural ventilation was analysed in a low-income dwelling to control open or closed windows according to a dynamic simulation process in sub-humid warm climate. A selective algorithm to control natural ventilation was determined in an annual period per hour with the following findings: a) an algorithm to select open or closed windows was determined, b) comfort hours per year were evidenced with open, closed windows and selective algorithm to operate natural ventilation, and c) the schedule and periods of ventilation control were presented. Meteonorm® data were used on an hourly basis in Design Builder® simulations and the Meteorological System data based on 30 years of measurements were used to determine the comfort range. Conclusions: the potential benefits to be obtained by applying this ventilation strategy with a selective algorithm are observed in sub-humid warm climate.

Dynamic modeling to support an integrated analysis among land use change, accessibility and gentrification

The gentrification phenomenon is characterized by the replacement of the prevailing social class living in a residential area by another one with a higher income due to improvements in technical and social infrastructures, such as upgrades in the accessibility conditions. Gentrification is a matter of great concern, especially in big cities of developing countries, where infrastructure provision should not reinforce patterns of sociospatial segregation. The main motivation of this work is to verify if land use transitions could lead to possible gentrification, under the influence of accessibility-related variables – such as the public transportation network, education and health equipments and the availability of employment. In order to represent a phenomenon that varies over time and space, the study proposes a dynamic modeling via cellular automata, using the validation of past simulations to measure the suitability of each accessibility variable to explain the observed land use transitions. The probability of each cell´s transition was calculated using the weights of evidence method considering the explanatory variables, based on the Bayes´ Theorem. The proposed model is applied in a case study that comprises districts in the southwestern sector of São Paulo city, Brazil, an area marked by the heterogeneity of its land use, with a considerable predominance of low-income dwellings. The work was based on spatial data from more than a decade (2000−2016), which besides providing information on land use, also enable the categorization of residential and retail buildings according to their standard and size. The modeling process revealed that for different ranges of each variable, transition trends usually associated with gentrification took place, such as the increasing presence of retail and services, the construction of new buildings in previously non-residential areas, the occupation of vacant land and the reduction of industrial use. However, observing the occurrence spots of those changes, it is reasonable to state that most of the occupation patterns found in each area tended to remain throughout the years, which means that low-income areas were not totally eliminated. Distinct levels of added value granted to the urban tissue were observed as a function of the predominant land use in each area – highlighting the complexity of the relationship between urban form and gentrification. The satisfactory results in the model validation confirmed the good performance of the explaining variables in modeling the urban form dynamics within the study area.

Socio–Economic Analysis of Riverine Flooding on Low-Income Dwellings: Adayar River, a Case Study

Abstract Flood damage assessment plays a vital role in providing information to policy developers. Nowadays, due to urbanization, the impact of flooding on communities is extensive, including tangible damage to property, the environment, and infrastructure as well as intangible damage due to stress, health hazards, and hardship. This paper provides an overview of a detailed flood assessment study conducted in the Kotturpuram Housing board area, located on the flood plain of the Adayar River in Chennai, India. A relatively simple approach to data collection was adopted, being a Questionnaire Survey (QS) as well as semi-structured interviews and observation techniques, due to data and research limitations. Losses due to damage to belongings and extra spending to buy essential commodities during flooding are also dealt with in this study. The flood mitigation costs for flooding that occurred in the year 2015 are also evaluated. A stage-damage curve was arrived at based on the information collected. Optimal and sustainable mitigation measures can be achieved only when the socio-economic aspects are adequately considered. Thus, this analysis was designed to estimate the effects of flooding on a community’s social and economic welfare, and thereby help to educate the community, including residents and officials, about the impact and magnitude of flooding. The outputs of the study will be the key inputs for designing flood mitigation and relief measures.

Contextualising adaptive comfort behaviour within low-income housing of Mumbai, India

Thermal adaptation in low-income housing of Mumbai, India is investigated using a longitudinal field study and in-situ field measurements. 705 set of responses from two different neighbourhoods were analysed to understand the patterns of behavioural adaptation. Spatial configuration, temporal factors and underlying societal norms influenced the comfort-related behaviour in low-income housing. Clothing adaptation was primarily governed by the gendered socio-cultural practice of purdah system and western influences rather than thermal needs. Logistic regression predicts probabilities of 88% and 20% for using ceiling fans and exhaust fans respectively at 80% indoor air relative humidity. However, thermal stimuli cannot predict occupant behaviour well due to presence of non-thermal determinants. Security, privacy, environmental nuisances (dust, noise and odour) and insects or animals menace (mosquitoes, monkeys, rats, lizards) were the major barriers to thermal adaptation. The study is helpful in evaluating the influence of occupant behaviour on building performance and thus to inform building design and operation. The policy implications could be through the development of design guidelines for the housing schemes to create thermally comfortable low-income dwellings.

Energy target pinch analysis for optimising thermal comfort in low-income dwellings

Technology acceptance plays a critical role in adopting thermal comfort strategies. Not only economic but socio-cultural context becomes pivotal when preference is considered. Yet, the fuzziness of what is acceptable remains under-researched in thermal comfort studies. This work intends to determine an optimal set of strategies for providing thermal comfort in low-income dwellings through a socio-technical methodology. A novel energy target pinch analysis (ETPA) method is developed for identifying optimal solution using a weighted Aggregate Acceptability Index. Data on thermal comfort and their willingness to acceptance was collected from 1267 low-income households in Mumbai, India. The study suggests that there exists a considerable gap in the acceptance of effective thermal comfort strategies by occupants of low-income housing and the interventions at community and policy level could be helpful in bridging this gap. The pinch analysis identified four sets of strategies in order of priority ranking involving adaptive actions and retrofit techniques for achieving thermal comfort under the acceptability constraints. The contribution of this study to thermal comfort literature is through a new ETPA optimisation method, for including the human choices function into the building energy efficiency and thermal comfort thereby providing pragmatic solutions for implementation.

The Effect of an Energy Refurbishment Scheme on Adequate Warmth in Low-income Dwellings

Many fuel poverty support programs have been implemented in the world. Energy-efficient retrofitting in low-income households is a main aspect of support programs in the context of energy saving, reduction of greenhouse gas emissions, and improvement of the thermal comfort and health of residents. This study analyzed the effects of an energy efficiency program for fuel poverty in Korea on the thermal comfort of residents. A total of 330 households were investigated wherein energy retrofits had been conducted. Indoor temperatures in the main bedroom and in the living room were recorded twice. The results showed that the average indoor air temperature in the surveyed households was 15.1 ± 3.7 °C, indicating that 95.2% of main bedrooms and 80.0% of living rooms did not meet the recommendations of the World Health Organization regarding temperature. These results indicated that the surveyed households did not use energy for heating their rooms, and an energy-saving effect due to the retrofits was difficult to expect. Accordingly, retrofit building or energy policies addressing fuel poverty are shown to be ineffective in the context of energy saving and thermal comfort in Korea. This article highlights issues that need to be analyzed to evaluate how effective the welfare program is. The results of this study alert policymaker to the need to improve the welfare policy; the methods proposed in this article will help them in their decisions.

Access to HIV Medication in the Community Versus a Nursing Home for the Medicare Eligible HIV population.

Access to appropriate antiretroviral therapy (ART) is key to people living with HIV/AIDS (PLWH) living a near normal life time, which has resulted in increasing numbers of PLWH requiring nursing home care for age-related reasons. However, one study found that 21% of Medicare eligible PLWH in US nursing homes between 2011 and 2013 were not dispensed ART through the nursing home pharmacy. Cost-sharing assistance programs exist to facilitate access to medications for low-income community dwelling older adults, but these programs do not necessarily extend to people admitted to a nursing home, which may cause interruptions in access to ART for PLWH in this setting. Policies may need to be updated to reduce drug-related financial burden to PLWH and nursing homes in order to maintain continued access to ART in the nursing home setting.

Traditional Kitchen Design for Sustainable Low-Income Dwellings in Developing Countries

The place of kitchens in contemporary designs is quite different from the traditional designs in terms of location, aesthetics and furnishing. Thus, this paper discussed development in kitchen designs over the past centuries and place emphasis on sustainable low-income kitchen design. The study examined the location of kitchens in contemporary dwellings in comparison with traditional dwellings in order to create a hybrid kitchen design that is sustainable, attainable and acceptable to contemporary and traditional individuals. Research methodology involved descriptive survey; with primary data obtained using structured questionnaire, systematic observation and interview with occupants of buildings in Awi community,  Akamkpa Local Government Area of Cross River State, Nigeria which is the study area. These were complemented with photographs of kitchens in the existing buildings within the area of study. 50 buildings purposely selected were studied to determine the designs, and placement/location of kitchens in these buildings in relation to the contemporary buildings respectively. Finally, the data collected were analyzed using simple statistical tool to obtain percentages, rankings and relative significance index (RSI) respectively to determine the reasons for the design and location of the kitchen. The result shows that of the five variables examined, cultural influence was the most significant reason for the location of kitchens outside the housing unit. The recommendation is that low-income dwelling should have kitchen space within in addition to the attached or detached kitchens in their dwellings.

Energy poverty methodology based on minimal thermal habitability conditions for low income housing in Spain

Energy poverty affects an increasing number of households in the European Union. It is urgent the development of definitions and methods adapted to regional conditions that gather important housing construction and climatic differences between Northern and Southern countries beyond different income levels. Mainstream energy poverty methods are focused on heating requirements influenced by health risks derived from living in cold homes. However, the evaluation of energy poverty in warmer climates must also consider health impacts related to households’ exposure to indoor overheating and consequent cooling needs that will likely be exacerbated by temperature increase due to climate change.The present research is aimed at developing a method for evaluating energy poverty in low income dwellings adapted to the Spanish context that gathers climatic, building and socioeconomic particularities of the country. The research was conducted through the evaluation of three representative social housing blocks of vulnerable households located in three different climates and regions. The proposed method is focused on the energy expenditure required to achieve minimal thermal habitability conditions in low income dwellings. Hence, both heating and cooling needs are appraised according to adaptive comfort criteria.The resulting method constitutes a useful tool for the identification of households suffering from energy poverty as well as the degree of the need they require (Fig. 1). Finally, the method poses an aid in the decision-making processes related to dwelling energy retrofitting actions and policy development.

Impacts of Domestic Solar Water Heating (DSWH) systems on the cost of a hot shower in low-income dwellings in Brazil

This work presents a method to evaluate, from the distribution utility's perspective, the impacts of adopting Domestic Solar Water Heating (DSWH) systems in Brazil, based on demand measurements carried out on two groups of residential households. For the 12 months period evaluated, the case-study shows that using DSWH results in savings of 198 kWh (38%), and active power demand savings at peak times of 860 W (42%) per individual unit. For the distribution utility and per individual unit, using DSWH leads to avoided costs of $ 27.59 (38%), avoided costs due to peak time demand reduction of $ 170.2 (42%), and annual avoided costs of $ 197.79 (41%). This work clearly shows that in the residential section the tariff model and structure is strongly distorted, since it only accounts for the energy consumption per residential unit, and completely disregards the costs associated with power demand availability. Our results show that in Brazil the distribution utility charges only some 15% of the real cost of a hot shower based on electric showerheads.

On the minimal thermal habitability conditions in low income dwellings in Spain for a new definition of fuel poverty

Fuel poverty can be defined as “the inability to afford adequate warmth in the home”. The concept was firstly developed due to health risks related to cold among low income households. However, in the last few decades, especially since the summer heat wave of 2003 that caused 35,000 deaths across Europe, a lot of research has been conducted about the health risks related to high temperatures.Along with advances in knowledge related to the health risks associated with inadequate temperatures, several directives of the European Commission related to energy regulation urge Member States to develop their own fuel poverty definitions. This need of a methodological development for new definitions poses several questions. First, what should be the temperature thresholds for the overheated season? But, furthermore, are existing temperature baselines adequate for the Spanish context and climate?This paper presents a preliminary approach to define these new temperature thresholds for the Spanish context through the adaptive comfort model criteria. For that purpose, a statistically representative dwelling building typology of vulnerable household spaces was used to analyze indoor thermal temperatures and hence, to establish minimal energy requirements so as to achieve minimal habitability conditions.