Energy Cost Burdens for Low-Income and Minority Households

Abstract

Problem, research strategy, and findings: Of the three primary components of housing affordability measures—rent, transportation, and utilities—utility costs are the least understood yet are the one area where the cost burden can be reduced without household relocation. Existing data sources to estimate energy costs are limited to surveys with small samples and low spatial and temporal resolution, such as the American Housing Survey and the Residential Energy Consumption Survey. In this study, we present a new method for small-area estimates of household energy cost burdens (ECBs) that leverages actual building energy use data for approximately 13,000 multifamily properties across five U.S. cities and links energy costs to savings opportunities by analyzing 3,000 energy audit reports. We examine differentials in cost burdens across household demographic and socioeconomic characteristics and analyze spatial, regional, and building-level variations in energy use and expenditures. Our results show the average low-income household has an ECB of 7%, whereas higher income households have an average burden of 2%. Notably, even within defined income bands, minority households experience higher ECBs than non-Hispanic White households. For lower income households, low-cost energy improvements could reduce energy costs by as much as $1,500 per year.

Takeaway for practice: In this study we attempt to shift the focus of energy efficiency investments to their impact on household cost burdens and overall housing affordability. Our analysis explores new and unique data generated from measurement-driven urban energy policies and shows low-income households disproportionately bear the burden of poor-quality and energy-inefficient housing. Cities can use these new data resources and methods to develop equity-based energy policies that treat energy efficiency and climate mitigation as issues of environmental justice and that apply data-driven, targeted policies to improve quality of life for the most vulnerable urban residents.     

Unequal access to energy efficiency in US multifamily rental housing: opportunities to improve

The energy efficiency of US multifamily rental housing is compared with other housing types. A real and growing energy efficiency gap is documented, particularly for lower income households. Findings are based on data from the 2005 and 2009 US Residential Energy Consumption Survey (RECS). Individual energy efficiency features related to HVAC (heating, ventilation and cooling) systems, appliances, and the building envelope are analysed along with weighted and unweighted total energy efficiency indices. Multifamily units occupied by low income renters had 4.1 fewer energy efficiency features in 2005 and 4.7 fewer in 2009 compared with other households. If the number of efficiency features was on par with other housing, the savings could be in the range of US$200–400 per year for most lower-income renters in multifamily buildings. There is an astonishing lack of information on how efficiency retrofits would affect property (real estate) metrics such as cash flow and value. Available evidence suggests that millions of US properties could be good retrofit investment opportunities. Better efficiency would allow renters to increase spending on food, healthcare and other essentials. This is not only an economic issue: it has implications for household health, social equity and environmental problems tied to energy consumption.     

Income,energy expenditure and housing in Madrid: retrofitting policy implications

Fuel poverty can be defined as ‘the inability to afford adequate warmth in the home’ and it is the result of the combination of three factors: low household income, lack of energy efficiency and high energy bills. Within this context, the present research is aimed at characterizing, for the first time, the housing stock of fuel-poor households in the Autonomous Region of Madrid. Fuel poverty incidence was established and households were divided into six different groups according to their relative position regarding fuel and monetary poverty. The housing stock of each group is characterized and those households most in need are identified. These results enable energy retrofitting priorities to be established, focusing on the needs of the different household groups and accounting for their housing stock characteristics. This allows Spanish energy retrofitting policies to be assessed for their capability of tackling fuel poverty and makes it possible to suggest some improvements.     

Heat metering: socio-technical challenges in district-heated social housing

Individual heat metering and charging (IMC) are seen as promising methods to reduce domestic heating and hot water use through the provision of financial incentives. The heat consumption measured by meters is influenced by both the dwelling characteristics and the behaviour of the occupant, but heating charges would ideally relate to occupant behaviour only. This dilemma can be especially relevant under two circumstances: if the thermal performance of the dwelling is poor and/or if heating costs represent a substantial part of the occupants' income, i.e. in social housing. The case of a district-heated council block in London is presented where the installation of individual heat meters was planned in 2010 but had to be suspended due to concerns about implications for occupant heating costs in light of the thermal performance of the building. It illustrates a technically and socially complex environment where fairness in allocating heating costs is an important concern. The case also shows how lack of funding or other issues on the infrastructure side can hinder behaviour-orientated measures such as IMC. A holistic energy conservation strategy addressing both physical building properties and occupant behaviour is therefore essential and should be supported by policy.     

Policy implications for the performance gap of low-carbon building technologies

ABSTRACT

It is widely recognized that the actual impact of low-carbon technologies is often lower than predicted by models alone, a phenomenon which has been coined the ‘performance gap’. Despite this awareness, in many instances estimates of both energy savings and renewable energy generation in domestic buildings continue to rely on engineering models and building energy simulations rather than approaches that are based on measured parameters. Much of the existing literature on the performance gap focuses on energy efficiency and is concerned with the quantification of the scale of the performance gap. This paper adds to this body of evidence by drawing retrospectively on a range of grey literature evaluations of low-carbon technologies (including energy-efficiency measures, renewable heat and renewable electricity) in the UK household sector. The focus is on not only the quantification of the performance gap but also the qualitative factors often overlooked, such as installation issues or installer/user behaviour. Recommended policy changes include the development of evaluation standards, the experimentation with pay-for-performance programmes, ensuring that installation standards for low-carbon technologies are being enforced, and taking reasonable steps to ensuring that end users can use any new technology effectively.     

Behavioural Patterns and User Profiles related to energy consumption for heating

The difference between the actual and predicted energy consumption for heating in housing is thought to be partly attributable to the use of HVAC systems. More reliable data on energy consumption could help in determining the actual energy performance of dwellings and in the search for the most adequate design for housing and home amenities. Further reductions on energy consumption might also be achieved if energy-saving policy programmes were geared to different household groups. The aim of this paper is to statistically determine Behavioural Patterns associated with the energy spent on heating and to identify household and building characteristics that could contribute to the development of energy-User Profiles. This study had two outcomes: it identified Behavioural Patterns to be used in energy calculations and it discerned User Profiles with different behaviours. Five underlying groups of behavioural variables were found, which were used to define the Behavioural Patterns and User Profiles. The groups showed statistically significant differences in the scores for most of the behavioural factors. This study established clear relationships between occupant behaviour and household characteristics. However, it seems difficult to establish relationships between energy consumption and Behavioural Patterns and household groups.     

Growth and change in one person households: Implications for the housing market

Abstract

As a result of several demographic and social trends, the one person household accounts for approximately one quarter of all households in Australia and is expected to further expand to one‐third by 2021. After couple families, the single person living alone is the most numerous household form. The paper differentiates one person households by life course stage and considers their likely housing demand in terms of tenure, dwelling type and number of bedrooms. Original analysis of the 1996 ABS 1% Household Sample File has been undertaken. Home ownership increased over the life course for singles, but not to the same extent as for other households. Moreover, there is some evidence to suggest that, household income aside, people living alone may prefer flats, units or apartments over detached houses. The paper suggests that our understanding of housing careers needs to incorporate the possibility of one or more spells as a one person household.     

Towards occupant-centric simulation-aided building design: a case study

ABSTRACT

This paper aims at illustrating the importance of occupant modelling for decision-making during the building design process. It identifies the energy implications of conventional ways of modelling occupants for the design of office buildings. Furthermore, it presents a step towards bridging the gap between the research efforts and conventional practices within the field of building performance simulation (BPS) aided design. The paper first describes occupant-related assumptions that were made during the design process of a case study office building, obtained via stakeholder interviews. Then, the impact of these assumptions on the design decisions is examined through a simulation-based investigation. The stakeholder interviews revealed that professionals from each design discipline made significantly different assumptions about occupants. The simulation results showed that assumptions about occupants and their behaviour impacted predicted energy savings of some design decisions by a factor of five or more.     

Transport,Housing and Urban Form: The Life Cycle Energy Consumption and Emissions of City Centre Apartments Compared with Suburban Dwellings

Buildings in cities and the activities carried out therein use a significant proportion of a nation's energy consumption and produce substantial quantities of greenhouse gases in the process. Residential buildings are a large contributor, partially as a result of the transport and housing activities of households. In this study, life cycle analysis is used to calculate the total transport and housing energy and emissions from a sample of 41 households in apartment buildings in the city centre of Adelaide, Australia and compare them with suburban households. The purpose of this is to determine whether the urban density option of higher rise dwellings offers a lower environmental impact than conventional housing. The analysis includes delivered energy and greenhouse gas emissions generated by motorised travel and activities within the dwellings, and the energy and emissions embodied in household motor vehicles and the apartment buildings. The total delivered energy consumption of apartment households was found to be lower than suburban households due mainly to higher car usage, particularly in the outer suburbs. However, the analysis of total greenhouse gas emissions provided a somewhat different comparison especially when they were considered on a per capita basis. The total per capita emissions for apartment households varied considerably but, on average, exceeded those of both the inner and outer suburban households. This resulted from lower occupancy rates and higher emissions arising from higher dwelling operational and embodied energy consumption. Overall, it cannot be assumed that centralised, higher density living will deliver per capita emission reductions for residents, once the combined per capita life cycle emissions from housing and transport have been accounted for. A more vigorous educational, promotional and regulatory approach is required to achieve greater operational and embodied energy efficiency in apartment buildings to fully realise the emissions-reducing potential of such buildings in centralised locations.

     

Socio‐Economic change within the older housing stock of Canadian cities

Traditional neo‐Classical economic theories of change in the older, inner city housing stock are primarily based on assumptions of a filtering down’ of housing quality and occupant households. As an alternative, this paper develops an approach that relies on societal and metropolitan transformations to explain the changing role of older, inner city neighbourhoods. It uses Statistics Canada's Household Income, Facilities and Equipment files for the years 1976 and 1986 in order to identify proportionate change in the characteristics of households occupying housing built before 1940 against those found throughout Census Metropolitan Areas. Most changes invalidate filtering down assumptions. Increases in incomes, the proportion of younger households, education levels, high status employment, all contribute to bring socio‐economic characteristics within older housing closer to the CMA norm. The paper considers the role protective zoning has played in inducing this form of upgrading. Attention is also given to the equivocal impacts of housing and neighbourhood improvement programmes aimed at lower income residents.     

How building design and technologies influence heat-related habits

ABSTRACT

The discrepancy between calculated heat demand and measured heat consumption – the performance gap – suggests that the energy efficiency of houses affects the energy-consuming habits of its occupants. This coincides with the theories of practice describing how materiality affects practices through reconfiguring practical understandings, e.g. comfort expectations. Heat-related habits are investigated in the paper across material contexts, e.g. building characteristics and technologies. Evidence based on a combined questionnaire survey and administrative data on occupants (n?=?1216) living in single-family detached houses in Denmark shows that the practices of adjusting thermostats and the amount of clothing worn indoors as well as perceived indoor temperature correlate with building characteristics, e.g. energy efficiency of the building envelope and technical installations. These correlations are moderated by the socio-demographic characteristics of occupants. However, building characteristics are found to be less influential on the frequency of opening windows. The results indicate that occupants dress warmer and keep lower temperatures in energy-inefficient houses. This suggests that material arrangements have a significant influence on occupant expectations and practices, which lead to increased indoor temperatures and energy demand. A challenge for building regulations will be to account for how energy efficient house characteristics and technologies adversely affect occupants’ energy-consuming behaviour.     

Uptake of energy efficiency interventions in English dwellings

Little detailed evidence has previously been available regarding the uptake rate or prevalence of energy efficiency interventions among specific household groups. This study uses the Home Energy Efficiency Database (HEED) to investigate both the combination of measures that have been installed, and in which dwellings, according to key neighbourhood socio-demographic variables, including income and tenure. Analysis of 2000–07 data indicates that approximately 40% (9.3 million) dwellings in England had approximately 23.7 million efficiency measures installed, with an average of 2.5 measures per dwelling. Building fabric-related measures were the most frequent (e.g. cavity wall insulation, loft insulation and glazing) with an average of 2.1 million installed each year. Dwellings with the highest number of fabric interventions (the top 20%) were more likely to be found in areas with low income, with more owner-occupied dwellings, experiencing lower winter temperatures, having a lower proportion of flats, and having a slightly higher proportion of older adults and children. Energy efficiency installations have tended to occur among specific types of households or parts of the building stock. These findings have implications for the design of future government programmes for targeting energy efficiency measures to specific household groups or dwelling types.     

Modeling the resiliency of energy‐efficient retrofits in low‐income multifamily housing

Residential energy efficiency and ventilation retrofits (eg, building weatherization, local exhaust ventilation, HVAC filtration) can influence indoor air quality (IAQ) and occupant health, but these measures’ impact varies by occupant activity. In this study, we used the multizone airflow and IAQ analysis program CONTAM to simulate the impacts of energy retrofits on indoor concentrations of PM_2.5 and NO₂ in a low‐income multifamily housing complex in Boston, Massachusetts (USA). We evaluated the differential impact of residential activities, such as low‐ and high‐emission cooking, cigarette smoking, and window opening, on IAQ across two seasons. We found that a comprehensive package of energy and ventilation retrofits was resilient to a range of occupant activities, while less holistic approaches without ventilation improvements led to increases in indoor PM_2.5 or NO₂ for some populations. In general, homes with simulated concentration increases included those with heavy cooking and no local exhaust ventilation, and smoking homes without HVAC filtration. Our analytical framework can be used to identify energy‐efficient home interventions with indoor retrofit resiliency (ie, those that provide IAQ benefits regardless of occupant activity), as well as less resilient retrofits that can be coupled with behavioral interventions (eg, smoking cessation) to provide cost‐effective, widespread benefits.     

Evaluating diverse patterns of occupant behavior regarding control-based activities in energy performance simulation

Simulation is recognized as an effective tool for building energy performance assessment during design orretrofit processes. Nevertheless, simulation models yield deviating outcomes from the actual building performance and a significant portion of this deviation originates from the dynamic nature of occupant behavior. Literature on occupant behavior indicates that occupant behavior is not integrated into building energy performance assessment procedures with appropriate resolution, instead they are acceptedas as sumedand fixed data sets that usually represent the presence of occupants. This study attempts to evaluate the effect of diverse patterns of occupant behavior on energy performance simulation for office buildings. Diverse levels of sensitivity of occupant behavior on control-based activities such as using lighting apparatus, adjusting thermostat settings, and presence in space are employed through three diverse occupant behavior patterns. These occupancy patterns are correlated with three identical office spaces simulated within a conceptual office building. EDSL Tas is used to run building energy performance simulations. Effects of occupant behavior patterns on simulation outcomes are compared for five sample winter and summer workdays, with respect to heating and cooling loads. Results present findings on how diversity of occupancy profiles influences the consumption outcomes.     

住区密度与家庭能耗碳排放相关性研究——以上海曹杨新村为例

住区空间形态及模式类型划分与密度特征相关,家庭能耗产生的空间碳排放与密度分布有着逻辑对应关系。国内外相关研究表明,家庭特征、住房特征和能耗行为等因素对家庭生活能耗有着显著的影响,而有关密度与家庭能耗碳排放之间的相关研究尚需更多实证案例。本文以上海曹杨新村作为研究对象,通过调研问卷数据来估算54个小区样本的家庭能耗人均碳排放值,并对住区密度指标与碳排放进行相关性研究。从回归分析结果看,曹杨新村的家庭能耗消费与家庭特征、住房特征等因素存在着显著的线性关系,且家庭人口规模具有主导作用。在密度指标与碳排放相关性研究中,家庭能耗碳排放在物质密度与人口密度指标中分别具有区段波动性特征,通过进一步分析密度与碳排放影响变量之间的非线性逻辑对应关系,研究得出不同密度区段条件下的住区家庭能耗碳排放差异是居民家庭人口规模、收入水平等相关社会因素叠合作用造成的。因此,判断住区是否"低碳"首先当明确密度区段的选择条件,结合本国国情、地区发展条件、家庭社会经济特征等因素来引导未来住区发展模式。     

How long do households remain in housing affordability stress?

We develop a model that specifies the duration of housing affordability stress for particular types of households. Using panel data from Australia, households are considered in semi- and parametric analysis against different household characteristics, revealing whether these characteristics predict the duration of housing affordability stress. For most types of households, an experience of housing affordability stress lasts less than one year. A group of household types disproportionately made up of renters and sole persons remains in stress for longer periods. Chronic housing affordability stress occurs if the duration of stress lasts for more than three years. Linking the duration of stress to household types, and demographic, financial and educational characteristics makes it possible to design more targeted, and therefore more efficient housing affordability policies.     

Critical factors affecting affordability of mortgage housing in Kenya

This study investigated factors affecting affordability in the mortgage housing sector in Kenya. Housing affordability is a major problem experienced by urban households in Africa. According to the African Development Bank (The middle of the pyramid: Dynamics of the middle class in Africa, market brief, 2011), only three per cent of the entire African population can afford a mortgage. In Kenya, the Centre for Affordable Housing Finance in Africa has estimated that only eleven per cent of urban households earn enough to support a mortgage. Attempts were made in this study to develop an empirical model to reveal the underlying factors affecting housing affordability in Kenya. Applying a multiple regression approach, the model identified that affordability of mortgage housing in Kenya is significantly driven by clusters of factors related to the households’ social-economic factors, property attributes, loan characteristics and the macroeconomic environment. Specifically, the interest on mortgage, number of households’ dependents, loan-to-value ratio, type of mortgage instrument, number of income earners in a household, real gross domestic product per capita and size of household are the critical factors affecting affordability with the greatest contribution to the affordability problems of households in the mortgage housing sector in Kenya.     

Moving or Improving: Housing Adjustment Choice in Kumasi,Ghana

This paper examines housing adjustment choice of households in Kumasi, Ghana. When a household is dissatisfied with its housing, it can choose to move elsewhere, improve the current dwelling, or neither. Using data from a 596-household survey collected in 1996, logistic regressions are used to examine the determinants of this choice. Results suggest that housing satisfaction and quality, plus some household characteristics, influence the choice of undertaking housing adjustment (including moving and improving). When a household decides to adjust, factors affecting the choice between moving and improving are housing conditions, tenure, household characteristics, and using housing for income generation through informal-sector activities.     

Unintended consequences: institutional artefacts,closure mechanisms and the performance gap

ABSTRACT

Renewable technologies often feature in policies to improve the energy efficiency of buildings. Designers introduce predicted energy values for specific technologies, but are surprised when the technologies fail to perform as expected. Three building projects are used to explore the effect of construction processes on the energy performance of building-integrated photovoltaic (BIPV) technology. In two cases BIPV failed to deliver expected energy generation, while in the third, dramatic changes in project processes and technical specifications were needed to achieve the specified output. A social construction of technology (SCOT) analysis documents how the energy generation of BIPV disappeared from view at certain points as actors focused on building features. A contribution is made to the theoretical development of SCOT by responding to two issues: privileging of cognitive closure mechanisms and the neglect of institutional analysis. The concept of inflection mechanisms is introduced as a second type of closure mechanism. More specifically, the role of institutional artefacts (e.g. planning requirements and schedules) in the construction process is found to contribute to the performance gap. To reduce the ‘performance gap’, practitioners need to focus on the distribution of design responsibility, sequencing of work and the location of expertise.