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This paper aims to understand the effect of different foundation designs of passive house on the resultant thermal bridges, at the junction between a wall and a slab on grade.

The linear thermal transmittances of some newly developed foundations of passive house are determined. The investigated foundation designs are L-element, U-element and foundation with foam glass technique.

It is found that the special design of passive house foundation can considerably influence the heat flow through thermal bridges. In this context, it is proposed a new foundation design of passive house, which has relatively low heat loss through thermal bridges. The results are compared with the “default” ISO values used to evaluate the effect of thermal bridges in typical buildings. It is found that there is large difference between the calculated linear thermal transmittances at the investigated foundations of passive house as compared to typical buildings.

The results can hopefully be used to improve the energy efficiency of the passive house.

Sustainable solution of buildings.

A new foundation design of passive house is suggested to reduce heat loss through thermal bridges.

If the building control system is to deliver housing which achieves major reductions in carbon dioxide emissions, it is important to ensure not only that energy efficiency standards are set at an appropriate level but also that the specification of standards takes into account realised performance. It is argued in this paper that, in many cases, there is a large gap between notional performance, as defined by the calculation methods embodied in the Building Regulations, and performance achieved in practice. Although it is accepted that some variation in performance is to be expected, there are a number of areas where closer attention to the methods used to estimate thermal performance, and the inclusion of hitherto unregulated aspects, could help to achieve a much closer match between what is expected and what is achieved. In particular, the paper discusses ways in which the Regulations could be improved so that the impact of thermal bridging, construction quality, window performance and airtightness are more closely controlled.

The purpose of this paper is to discuss the methodology and results of using thermography for pre‐retrofit (pre‐R:T) and post‐retrofit (post‐R:T) surveys undertaken to qualitatively assess retrofitted external wall insulation (EWI) on pre‐1919 existing dwellings with solid exterior walls.

This study involved undertaking qualitative thermography surveys before and after installation of EWI at two mid‐terrace dwellings in Swansea (UK). One dwelling was part of a whole‐street approach and the other was an isolated installation.

The two case studies have provided evidence of potential thermal bridges created as a result of an incomplete covering of EWI. Whilst overall heat loss appears to have been reduced, further evidence is required to establish the extent to which these thermal bridges reduce overall thermal performance.

Only two schemes undertaken in Swansea (UK) are represented in this study and are therefore not a reflection of EWI installations generally. Nevertheless, the study suggests more general concerns with the installation of EWI where a continuous covering of insulation cannot be achieved. Further research is required to assess the long‐term implications of thermal bridges on the condition of the dwelling and the health of occupants.

This paper has introduced and tested a pre‐R:T and post‐R:T methodology for assessing the thermal performance of deprived dwellings, which have had EWI retrofitted to solid exterior walls. By using the pre‐R:T and post‐R:T methodology the paper has demonstrated a visual method for illustrating problems in retrofitting EWI and highlighted improvements in thermal performance, which can be used by stakeholders involved in the maintenance and improvement of existing dwellings.

Although vacuum insulation panels (VIPs) are thermal insulators that combine high thermal performance with limited thickness, application in the building sector is still rare due to lack of scientific knowledge on the behaviour of these panels applied in building constructions. This paper, therefore, seeks to give an overview of the requirements for and the behaviour of VIPs integrated into building components and constructions. Moreover, the interaction between different requirements on and properties of these integrated components are discussed in detail, since a desired high quality of the finished product demands an integral approach regarding all properties and requirements, especially during the design phase. Therefore, the importance of an integral design approach to application of VIPs is shown and emphasized in this paper.

To achieve this objective, the legally and technically required properties of VIPs and especially their interrelationships have been studied, resulting in a relationship diagram. Based on these investigations of thermal‐ , service life‐ and structural‐properties have been selected to be studied more elaborately using experimental set‐up for structural testing and simulation software for thermal and hygrothermal testing.

Two relationships between requirements or properties were found to be of principal importance for the design of façade components in which VIPs are integrated. First, thermal performance requirements strongly interact with structural performance, principally through the edge spacer of this façade component. A high thermal performance requires minimization of the thermal edge effect, in most cases reducing the structural performance of the entire panel. Second, an important relationship between thermal performance and service life has been recognised. The operating phenomenon mainly governing this interaction is thermal conductivity aging.

Most research in the field of vacuum insulation until now has been directed towards gaining knowledge on specific properties of the product, especially on thermal and hygrothermal properties. The relationships and interactions between these properties and the structural behaviour, however, have been neglected. This paper, therefore, addresses the need for an integral design (and study) approach for the application of VIPs in architectural constructions.

The purpose of this study is to investigate and analyse the potential of existing buildings in the UK to contribute to the net-zero emissions target. Specifically, it aims to address the significant emissions from building fabrics which pose a threat to achieving these targets if not properly addressed.

The study, based on a literature review and ten (10) case studies, explored five investigative approaches for evaluating building fabric: thermal imaging, in situ U-value testing, airtightness testing, energy assessment and condensation risk analysis. Cross-case analysis was used to evaluate both case studies using each approach. These methodologies were pivotal in assessing buildings’ existing condition and energy consumption and contributing to the UK’s net-zero ambitions.

Findings reveal that incorporating the earlier approaches into the building fabric showed great benefits. Significant temperature regulation issues were identified, energy consumption decreased by 15% after improvements, poor insulation and artistry quality affected the U-values of buildings. Implementing retrofits such as solar panels, air vents, insulation, heat recovery and air-sourced heat pumps significantly improved thermal performance while reducing energy consumption. Pulse technology proved effective in measuring airtightness, even in extremely airtight houses, and high airflow and moisture management were essential in preserving historic building fabric.

The research stresses the need to understand investigative approaches’ strengths, limitations and synergies for cost-effective energy performance strategies. It emphasizes the urgency of eliminating carbon dioxide (CO₂) and greenhouse gas emissions to combat global warming and meet the 1.5° C threshold.

Despite the number of quality management procedures being currently applied, construction defects in the domestic sector are acknowledged to contribute to the energy performance gap of buildings. This paper investigates the limitations and challenges to the implementation of project quality plans (PQPs) and their impact on the achievement of expected thermal performance in the UK social housing projects.

A qualitative approach, guided by grounded theory, was used in this research. This methodology provided the structure for systematic data analysis iterations, enabling cross-case analysis. An analytic induction process was designed to seek the explanation of the targeted phenomenon and required data collection until no new ideas and concepts emerged from the research iterations. This study collected data from five social housing projects through interviews, site observations and project documentation.

Multiple limitations and challenges were identified in the implementation of PQP to deliver thermal efficient social housing. Generally, there is the need for more objective quality compliance procedures based on required evidence. When investigating the root of the challenges, it was concluded that the adoption of statutory approval as the main quality compliance procedure led to the dilution of the responsibility for prevention and appraisal of defects that compromised the effectiveness of PQP devised by housing associations (HA) and contractors.

This study identifies the shortcomings of PQP in addressing quality issues with potential to undermine the thermal performance of social housing projects. The findings could be used by HA, contractors and policymakers as steppingstones to improve the energy efficiency in the domestic sector.

The purpose of this paper is to provide a detailed appraisal of the quality of domestic retrofits.

This paper presents the results of technical surveys on 51 retrofits undertaken before, during and after the retrofits.

Failures are observed to be endemic and characterised into five themes: 72 per cent showed moisture issues pre-retrofit, 68 per cent had moisture risks post-retrofit, 62 per cent did not adopt a whole house approach, 16 per cent showed inadequate quality assurance protocols and 64 per cent showed evidence of insufficient design detailing. Each theme is further subcategorised with a view to identifying implications for future policy.

The findings suggest the 10 per cent Ofgem retrofit failure rates predictions are an underestimate and so there may be a need for additional investigations to understand the trend across the UK.

Recommendations to reduce the failure rates may include making changes to the current inspection regime, widening understanding among installers; providing standard repeatable designs for repeated features; and empowering occupants to trigger inspections.

The sample is representative of a substantial proportion of the homes in the UK suggesting that retrofit quality may in many instances be below the required standards.

Risks of moisture issues and underperformance in domestic retrofit are a concern for government industry and households. This research shows that many installation failures are the result of not implementing existing guidelines and a change to the enforcement of standards may be needed to enact a fundamental change in installer practice and process control.

Increasing power densities within electronic equipment have led to a rise in the number of heat related problems being experienced. This paper describes the use of computerised thermal analysis techniques to optimise the design of passive thermal management systems for electronic equipment.

The purpose of this paper is to analyze energy performance of the multi-storey buildings built in the city of Tlemcen between 1872 and 2016.

A diagnosis based on a bottom-up methodology, using statistical techniques and engineering, has been developed and applied. To do this, demand condition analysis was conducted using a data collection survey on a sample of 100 case studies. Physical characteristics of the buildings have been determined through the archetype by period. This serves to define the strengths and weaknesses of buildings as energy consumers.

The obtained results showed that dwellings built between 1872 and 1920 offer better energy performance with a consumption index close to 130kWh/m²/year and this compared to the five periods considered. For dwellings built between 1974 and 1989, energy consumption is higher with an index approaching 300kWh/m²/year, thus qualifying the buildings of this period as energy intensive.

A database is established to collect physical information on the existing housing stock and thus allow their classification vis-à-vis of the energy label. This study is part of a research project aimed at evaluating and determining optimal measures for energy rehabilitation of multi-family buildings in Tlemcen. Thermal rehabilitation solutions are proposed using thermal simulations, in the following studies, to improve thermal performance of existing buildings. This study constitutes the first step of a roadmap applicable to other cities constituting climatic zones in Algeria. This helps to enrich the Algerian thermal regulation in thermal rehabilitation of existing residential buildings and conception of new ones, in urban areas with a similar climate.