Overheating in care settings: magnitude,causes, preparedness and remedies

ABSTRACT

Research in UK and elsewhere has highlighted that older people are particularly vulnerable to negative health effects of overheating. This paper examines the magnitude, causes, preparedness and remedies for addressing the risk of summertime overheating in four case study residential care and extra-care settings across the UK, spanning different building types, construction and age. An interdisciplinary approach is adopted, drawing from building science and social science methods, including temperature monitoring, building surveys, and interviews with design and management teams. The findings suggest that overheating is a current and prevalent risk in the case study schemes, yet currently little awareness or preparedness exists to implement suitable and long-term adaptation strategies (e.g., external shading). There was a perception from designers to managers, that cold represents a bigger threat to older occupants’ health than excessive heat. A lack of effective heat management was found across the case studies that included unwanted heat gains from the heating system, confusion in terms of responsibilities to manage indoor temperatures, and conflicts between window opening and occupant safety. Given that care settings should provide protection against risks from cold and hot weather, design, management and care practices need to become better focused towards this goal.     

Overheating in Auckland homes: testing and interventions in full-scale and simulated houses

ABSTRACT

New Zealand dwellings have thermal conditions managed with relatively light regulation. No minimum airtightness standards exist and historical increases in required insulation levels aimed to reduce winter heating energy consumption. A consequence of this policy is an increased potential for overheating in summer. There has been a steady increase in the use of heat pumps, risking heating energy savings being outweighed by cooling energy increases. Internal temperatures and humidity were monitored in the living spaces of three unoccupied, transportable houses over all four seasons of the Auckland climate. The houses are located on the same site and are of identical construction, apart from selected interventions which were tested to explore their potential to mitigate overheating. Results indicate that overheating can be extreme and long lasting. High internal temperatures are very closely connected with solar gains. Internal temperatures reached 32°C in autumn. Roof space temperatures reached 51°C in summertime. Interventions resulted in modest improvements and an airtight construction provided a small thermal benefit. A thermal model for the houses was developed using EnergyPlus and compared with actual measurements and the interventions. Early results point to the further need to reduce solar gain, increase roof-space ventilation and increase mass, where feasible.     

Overheating in Scotland: contributing factors in occupied homes

ABSTRACT

There is growing awareness of the overheating risks in new-build properties in the UK. However, this tends to be considered a problem principally for the southern regions in the UK, only becoming a serious issue in the north of England in the medium-term and in the long-term for Scotland. This notion tends to be largely predicated upon climate change predictions, differences in latitude and summer air temperatures. This paper describes the results from Building Performance Evaluation (BPE) studies over a two-year period from 26 occupied new-build homes across Scotland which demonstrated incidences of overheating. Results suggest that low-energy buildings are susceptible to overheating despite northerly latitudes, with 54% of houses studied overheating for more than six months annually, and 27% of homes overheating for less than 10% of the year. Evidence indicated that commonly used prediction tools do not appear to anticipate overheating adequately. This paper maps common overheating causes due to design and the role of occupants, identifying the risks due to the regulatory system, prediction and procurement processes, and design and construction. A common finding was that design and occupancy factors appear to have a greater impact on overheating more than location and climatic factors.     

Overheating in vulnerable and non-vulnerable households

ABSTRACT

As the 2003 European heatwave demonstrated, overheating in homes can cause wide-scale fatalities. With temperatures and heatwave frequency predicted to increase due to climate change, such events can be expected to become more common. Thus, investigating the risk of overheating in buildings is key to understanding the scale of the problem and in designing solutions. Most work on this topic has been theoretical and based on lightweight dwellings that might be expected to overheat. By contrast, this study collects temperature and air quality data over two years for vulnerable and non-vulnerable UK homes where overheating would not be expected to be common. Overheating was found to occur, particularly and disproportionately in households with vulnerable occupants. As the summers in question were not extreme and contained no prolonged heatwaves, this is a significant and worrying finding. The vulnerable homes were also found to have worse indoor air quality. This suggests that some of the problem might be solved by enhancing indoor ventilation. The collected thermal comfort survey data were also validated against the European adaptive model. Results suggest that the model underestimates discomfort in warm conditions, having implications for both vulnerable and non-vulnerable homes.     

Meta-analysis of indoor temperatures in new-build housing

ABSTRACT

Despite growing concerns about overheating, a lack of evidence exists on the scale of the problem, particularly in contemporary UK housing. This paper presents the results of a meta-analysis of indoor temperatures in selected low-energy housing. Temperature data recorded at five-minute intervals in 60 dwellings across 19 demonstration projects (2012–14) were collated and analysed to investigate the prevalence of overheating. Findings evidence high summertime temperatures, with 27% of living rooms exceeding 28°C during August. Based on the Chartered Institution of Building Services Engineers (CIBSE) threshold of 5% annual occupied hours > 25°C, 57% of bedrooms and 75% of living rooms were classified as having overheated. Overall, 30% of living rooms exceeded the adaptive comfort threshold of > 3% occupied hours ΔT?≥?1?K. The results suggest a fundamental relationship between ventilation and indoor temperatures. The higher minimum and average summertime temperatures observed in mechanical ventilation with heat recovery (MVHR) homes (p?<?0.05) and lower temperature range (p?<?0.001) suggest the need for greater attention to adequate summertime ventilation provision in airtight homes. The results demonstrate a high prevalence of overheating in exemplary housing, indicating the need for greater efforts to ensure the effective implementation of strategies to minimize overheating and improve ventilation in low-energy homes.     

Combating overheating: mixed-mode conditioning for workplace comfort

ABSTRACT

Using post-occupancy evaluations of seven mixed-mode buildings – three in Australia and four in India – this paper demonstrates that effective mixed-mode conditioning (instead of year-round air-conditioning) can deliver comfortable workspaces. Occupant feedback reinforces strong associations between overheating, thermal comfort, overall comfort and perceived productivity. However, differing levels of thermal acceptability within and between the Australian and Indian contexts are evident. Occupants in the Indian buildings were found to tolerate a wider range of temperatures when compared with Western contexts where lower temperature limits entrench an energy demand through a greater reliance on air-conditioning. The outcomes from the study suggest that the perception of overheating and consequent risk to building performance can be intensified when occupants perceive limited adaptive opportunity or problems are not rectified quickly, whereas perceived control is less important where building systems are user responsive. Occupants in three of the study buildings also perceived higher-than-anticipated comfort which could be attributable to well-liked attributes, such as break-out spaces, daylight and fresh air included in these buildings. The findings challenge designers and clients to develop user-responsive climate interactive workplaces that capitalize on spatial and mixed-mode environmental control to tackle the question of overheating.     

Inhabitant actions and summer overheating risk in London dwellings

ABSTRACT

An indoor overheating assessment study of 101 London dwellings during summer 2009 is presented. The study included building surveys, indoor dry bulb temperature monitoring and a questionnaire survey on occupant behaviour, including the operation of passive and active ventilation, cooling and shading systems. A theoretical London housing stock comprising 3456 combinations of building geometry, orientations, urban patterns, fabric retrofit and external weather was simulated using the EnergyPlus thermal modelling software. A statistical meta-model of EnergyPlus was then built by regressing the independent variables (simulation input) against the dependent variables (overheating risk). The monitoring and questionnaire data were analysed to explore the relationship between self-reported behaviour and overheating, and to test the meta-model. The monitoring data indicated that London homes and, in particular, bedrooms are already at risk of overheating during hot spells under the current climate. Around 70% of respondents tended to open only one or no windows at night mainly due to security reasons. An improvement in the coefficient of determination (R²) values between measured temperature and meta-model predictions was obtained only for those dwellings where occupants reported actions that were in line with the modelling assumptions, thus highlighting the importance of occupant behaviour for overheating.     

Probabilistic climate projections with dynamic building simulation: Predicting overheating in dwellings

This study, as part of the Low Carbon Futures project, proposes a methodology to incorporate probabilistic climate projections into dynamic building simulation analyses of overheating in dwellings. Using a large climate projection database, suitable building software and statistical techniques (focussing on principal component analysis), output is presented that demonstrates the future overheating risk of a building in the form of a probability curve. Such output could be used by building engineers and architects to design a building to an acceptable future overheating risk level, i.e. providing evidence that the building, with specific adaptation measures to prevent overheating, should achieve thermal comfort for the majority of future climate projections. This methodology is overviewed and the use of the algorithm proposed in relation to existing building practices. While the methodology is being applied to a range of buildings and scenarios, this study concentrates on night-time overheating in UK dwellings with simple and achievable adaptation measures investigated.     

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.     

Co-producing,curating, and defining design knowledge in an online practitioner community

ABSTRACT

As co-design and other participatory design practices increasingly make design outcomes more accessible to everyday citizens, it is also important to understand how designers negotiate the value of design knowledge that undergirds design action and share this knowledge within their own community to facilitate and evolve their practices. In this study, we analyze UX practitioners’ interactions on Reddit, including patterns of resource sharing and curation that point towards a collective construction of UX as a design discipline. We identified how knowledge from diverse sources was selected and shared with the subreddit community (co-production); the resources that community members engaged with and to what extent (curation); and the collective body of knowledge that characterised the design community (definition of design knowledge). We found that boundary work that sought to define the value of UX knowledge often took place at the periphery of shared resources, either expanding or rearticulating the boundary of UX knowledge in relation to trends in employment and nascent professionalisation. Implications of this work for the co-creation of knowledge to support design practices are considered, focusing on how design knowledge concomitantly shapes and is shaped by client-directed design action.     

Exposure duration in overheating assessments: a retrofit modelling study

ABSTRACT

A new indicator of overheating risk is introduced that more comprehensively represents heat stress and the way thermal environment is experienced. This indicator is compared with the industry standard overheating assessment approach (CIBSE TM52). This is demonstrated using an energy retrofit simulation case study of a typical London, UK terraced dwelling under different climate scenarios. Overheating was evaluated first according to TM52, then via an assessment of continuously overheated intervals (COIs) that account for the duration where adaptive limits are continuously exceeded. Results for the case study show that, first, extent of overheating can vary greatly based on climate uncertainties. Second, insulation retrofit only contributes to substantial overheating when the space lacks proper ventilation or protection from solar radiation. Nevertheless, overheating cannot be avoided completely under future climate scenarios even with appropriate passive cooling. More importantly, the results show that overheated hours tend to occur consecutively. This implies that violations of TM52 criterion 1 (which currently applies only at the seasonal scale) can occur at the monthly/weekly resolutions. This ‘buried’ information can be revealed via the COI approach to more comprehensively capture how an overheating situation unfolds in a manner more relevant to heat stress and occupants’ thermal experience.     

Materializing performance and ritual: decoding the archaeology of movement in tallensi shrines in northern ghana

ABSTRACT

The static is often given prominence within much archaeological interpretation and conceptualization in relation to ritual and religion. This is potentially due to the fact that static material residues are being considered and, in turn, this static image is transferred onto the ritual practices, beliefs, and communities that generated the archaeological material. Instead some of the material encountered archaeologically might be structured by much more dynamic, fluid, and active ritual behaviors. Considering performance, movement, and bodily understandings in relation to space and material culture offers a potential mechanism to begin to explore this, and will be considered with reference to the Golib festival and the archaeology of Tallensi shrines in the Tongo Hills of the Upper East Region in Northern Ghana.     

Will future low-carbon schools in the UK have an overheating problem?

Meeting thermal comfort and internal air quality standards for schools can be difficult for buildings that, traditionally in the UK, have not used mechanical ventilation and air-conditioning. With a trend towards increased internal gains, and climate change predicted to cause a significant rise in temperatures, this issue becomes more problematic. Considering this within the context of low-carbon buildings creates an added hurdle—can low-carbon schools be produced that will provide a comfortable teaching environment in the future? Through a series of simulations on template school buildings, this study highlights the effect that future small power and lighting energy use could have on reducing the overheating of school teaching areas. The effect of a warming climate is also estimated, and the impact that has on the internal temperatures of a school quantified. Introducing external shading and increasing ventilation in classrooms can reduce overheating significantly but, for many cases, the risk that the school building cannot cope with the overheating problem might still remain.     

Managing professional jurisdiction and domestic energy use

ABSTRACT

Professionals involved in organizing and undertaking domestic works, such as extensions, maintenance and refurbishment, have an important role in influencing how homes are configured and how occupants live within them. Despite this, the professional identities of these actors, and their impact on domestic energy use, is often overlooked. In response, this paper argues that one useful way of examining their influence is to consider how professional identities shape everyday working practices in relation to clients. Data from two UK interview and observation studies are combined: one with heating installers and the other with architects. The data are analysed using concepts from Abbott’s ‘system of professions’ framework that focuses on how the routine working practices of professional groups are born of how they see themselves and the tasks for which they are responsible. This comparison provides insights into how these two groups manage their professional ‘jurisdictions’ during their client interactions and what this means for policy-makers and industry representatives hoping to influence their work in pursuit of less carbon-intensive living. It also points to the value of further in-depth studies that explore how the routine management of professional jurisdiction impacts upon domestic energy use in a range of contexts.     

Materialities shape practices and notions of comfort in everyday life

ABSTRACT

The development of residential energy technologies aims to ensure thermal comfort in an increasingly energy-efficient manner. This development influences everyday practices related to comfort in everyday life in dwellings. Therefore, an empirical analysis of interviews with residents in three types of Danish detached houses, related to the building age, is used to understand how changes in technologies influence residents’ practices and notions of comfort. Detached houses are the most widespread type of housing in Denmark, constituting 44% of the housing stock. The analysis focuses on differences in heating systems between the housing types and shows how changes in technologies and material structures shape the practices of heating and airing. A shift in technology from radiators to underfloor heating was found to make a clear difference in both how houses are heated and thermal comfort is perceived. It is found that changes in material structures of houses consequently change residents’ perceptions of comfort and the related everyday practices. A more nuanced set of notions of comfort is developed in relation to different practices, and specifically the relation between airing and heating practices, as well as the context of seasons and the outdoors.     

Understanding the contextual influences of the health outcomes of residential energy efficiency interventions: realist review

Abstract

Residential energy efficiency interventions are complex social and construction programmes that may benefit health, yet the interactions between the material improvements, health and health-related outcomes, and householder responses are not well understood. While indoor winter warmth and householder satisfaction have been identified as the key mediators for physiological, mental and social health outcomes, this paper explores how programme contexts may have influenced the outcomes. This review revealed that common target populations were low income households, children and the elderly. The review found that people’s expectations and culturally constructed heating practices influenced indoor temperatures and householder satisfaction. Very deprived households were still affected by financial constraints despite the intervention measures. Excessive ventilation and limited technical mastery counteracted the beneficial effects of the intervention measures. Poor workmanship and ineffective handover undermined energy consumption objectives and led to householder dissatisfaction. Effective intervention design should address householder needs and the programme’s sociocultural context.     

Socially innovative housing activism: local context and collective leadership practices in Barcelona and New York City

Abstract

Drawing upon a comparison between four socially innovative housing activism initiatives, this paper makes new theoretical propositions on the nature of social change by bringing together a contextual approach on housing activism and an agency analysis of collective leadership practices. On one hand, this paper analyses how historical and geographical neighbourhood features constrain and enable housing activism. On the other hand, the paper unveils collective leadership practices that democratize socially innovative initiatives and make social change happen. Assuming that housing activism is spatially and institutionally embedded, the paper concludes that some leadership practices not only enable the emergence of such processes but also foster their sustainability and increase their impact.     

Practice-based learning in construction projects: a literature review

Construction project managers often face problems when trying to change work practices. Management research addresses these problems by offering stylized and abstract models; unfortunately, they may say little about the actual work practices that managers want to change. Practice theory offers an alternative way to address practice-related managerial problems, arguing that learning is a central enabler of performing practices. While some early research on practice-based learning in construction management exists, an understanding of how this theory has been applied is lacking. To address this limitation, a systematic literature review of 15 published construction management articles was conducted, the articles being divided into five practice-related analytical categories: participation, context, meaning production, power and becoming a practitioner to identify the areas of theory discussed. Participation and context were discussed more in the published articles than meaning production, power and becoming a practitioner, which might suggest that the latter categories offer more possibilities for future research. Further, the articles were analysed through a Lakatosian research programme lens, showing that a progressive research programme exists in practice-based studies in construction management. These findings provide avenues for future construction management studies seeking to apply practice-based learning theory to understand learning in construction projects better.     

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.     

Enclaves of America: The Rhetoric of American Political Architecture Abroad, 1900–1965

Abstract

This postoccupancy evaluation of participatory architecture undertaken by Belgian architect Lucien Kroll highlights discrepancies between intention and realization. A review of Kroll's published statements as well as interviews with him and with the inhabitants reveals that neither fully obtained their desired results. This article describes the aspirations of both architect and inhabitants for this small housing development in France and their respective disappointments with the fruits of their labors. It then suggests strategies for learning from this experiment to refine participatory practices in the future.