Development and validation of a building design waste reduction model

Reduction in construction waste is a pressing need in many countries. The design of building elements is considered a pivotal process to achieve waste reduction at source, which enables an informed prediction of their wastage reduction levels. However the lack of quantitative methods linking design strategies to waste reduction hinders designing out waste practice in building projects. Therefore, this paper addresses this knowledge gap through the design and validation of a Building Design Waste Reduction Strategies (Waste ReSt) model that aims to investigate the relationships between design variables and their impact on onsite waste reduction. The Waste ReSt model was validated in a real-world case study involving 20 residential buildings in Spain. The validation process comprises three stages. Firstly, design waste causes were analyzed. Secondly, design strategies were applied leading to several alternative low waste building elements. Finally, their potential source reduction levels were quantified and discussed within the context of the literature. The Waste ReSt model could serve as an instrumental tool to simulate designing out strategies in building projects. The knowledge provided by the model could help project stakeholders to better understand the correlation between the design process and waste sources and subsequently implement design practices for low-waste buildings.

Architects' perspectives on construction waste reduction by design

The construction, demolition and excavation waste arising in England was estimated at 91 million tonnes in 2003. The current thinking on construction waste minimisation is heavily focussed on several issues relating to physical construction waste and recycling guides. Indeed, much had been published on ways to improve on-site waste management and recycling activities but very few attempts made to address the effect of design practices on waste generation. However, there is a consensus in the literature that the architect has a decisive role to play in helping to reduce waste by focussing on designing out waste. This paper examines previous studies on architects' approach towards construction waste minimisation; and by means of a postal questionnaire, investigates: the origins of waste; waste minimisation design practices in the UK; and responsibilities and barriers within the UK architectural profession. The findings reveal that waste management is not a priority in the design process. Additionally, the architects seemed to take the view that waste is mainly produced during site operations and rarely generated during the design stages; however, about one-third of construction waste could essentially arise from design decisions. Results also indicate that a number of constraints, namely: lack of interest from clients; attitudes towards waste minimisation; and training all act as disincentives to a proactive and sustainable implementation of waste reduction strategies during the design process.

IgA nephropathy in Pakistan

A light, electron and immunofluorescence microscopy study was performed on 102 consecutive patients on whom suitable percutaneous renal biopsies were obtained. In this selected group of patients primary IgA glomerulonephritis was diagnosed in 6 (5.9%) cases. On light microscopy the glomerular lesions were predominantly focal (WHO class III) and diffuse mesangial proliferative glomerulonephritis (Class IV). The mesangial deposits showed high association with IgM deposits and presence of early complement components (C1q, C4) indicative of both classical and alternative pathways of C3 activation in our patients. The high incidence of nephrotic syndrome with microhaematuria (5 cases) is due to patient selection when compared to other studies. This study shows the existence of IgA nephropathy in Pakistan and larger number of cases need to be investigated to determine the true prevalence of this disease and its clinical manifestations and importance in Pakistan.