Improving the quality management systems for energy-efficient social housing projects

Developing and implementing quality management systems (QMS) in construction is particularly difficult because of a lack of standardization, the use of transient workforce and the many parties involved. This paper discusses the challenges faced by social housing providers in the UK when implementing quality assurance programs in their effort to provide their tenants with energy-efficient dwellings. In particular, it focuses on the quality plans defined at the early stages of a project, their impact during the construction process and on the resulting building energy performance. Based on data collected from the project team and documentation, a comparative analysis of the QMS development process of two social housing developments is presented. The key findings show that the two case studies followed different quality management approaches to deliver energy efficient dwellings. The most significant discrepancies were found in defining the energy performance targets and detailing the quality assurance procedures. The contribution of this paper is to create awareness of the importance of defining Quality Assurance Systems with a focus on energy performance from the early stages of a project

Quality management in UK social housing projects: Addressing thermal performance

Construction defects in the domestic sector, especially those occurring in the building fabric, are acknowledged to contribute to the mismatch between the energy use as predicted at design stage and as measured in the building operation. Despite the number of quality management procedures put in place in social housing projects, defects affecting the thermal performance of dwellings are still a major issue to be managed. Within this context, this study investigates how Project Quality Plans related to thermal performance of dwellings are defined and implemented in the UK social housing projects. The analysis of evidence collected from five social housing case studies suggests that in the majority of the projects, the deployed quality management procedures focuses on visual quality issues, allowing defects with the potential to impair the thermal performance of the dwellings to remain uncorrected. Despite a range of quality control procedures administered by the projects' stakeholders, they did not systematically appraise such defects neither during preconstruction phase, nor during the construction stage. This study identifies the main challenges posed to the development and implementation of Project Quality Plans with focus on the thermal performance of dwellings. In addition, recommendations focused on offsetting the identified challenges are proposed as means to mitigate the quality issues affecting the thermal performance in social housing projects

The impact of defects on energy performance of buildings: Quality management in social housing developments

Construction defects in the domestic sector, especially occurring in the building fabric, are acknowledged to contribute to the energy performance gap of buildings. Discontinuity of insulation layers, gaps in the vapor/air barriers and thermal bridging through building elements lead to undesired heat loss, and thus to the increase of energy use for space heating. This study set out to investigate how quality management systems related to energy performance of buildings are defined and implemented in social housing projects in the UK. The analysis of evidence collected from a number of Housing Association case studies suggests that in the majority of the projects, the deployed quality management procedures focused on visual quality issues, allowing defects with the potential to impair the thermal performance of the dwellings to remain uncorrected. Despite a range of quality control procedures administered by the client, contractor and independent agents, they did not systematically appraise such defects during the construction stage. Apart from one case study, the quality management systems implemented in the projects lack an objective definition of the compliance methodology when addressing to the energy performance quality criteria

Fludarabine increases nuclease-free AAV- and CRISPR/Cas9-mediated homologous recombination in mice

: Homologous recombination (HR)-based gene therapy using adeno-associated viruses (AAV-HR) without nucleases has several advantages over classic gene therapy, especially the potential for permanent transgene expression. However, the low efficiency of AAV-HR remains a major limitation. Here, we tested a series of small-molecule compounds and found that ribonucleotide reductase (RNR) inhibitors substantially enhance AAV-HR efficiency in mouse and human liver cell lines approximately threefold. Short-term administration of the RNR inhibitor fludarabine increased the in vivo efficiency of both non-nuclease- and CRISPR/Cas9-mediated AAV-HR two- to sevenfold in the murine liver, without causing overt toxicity. Fludarabine administration induced transient DNA damage signaling in both proliferating and quiescent hepatocytes. Notably, the majority of AAV-HR events occurred in non-proliferating hepatocytes in both fludarabine-treated and control mice, suggesting that the induction of transient DNA repair signaling in non-dividing hepatocytes was responsible for enhancing AAV-HR efficiency in mice. These results suggest that use of a clinically approved RNR inhibitor can potentiate AAV-HR-based genome-editing therapeutics