Mohamed Osmani

The impact of Local Authorities’ interventions on household waste collection: A case study approach using time series modelling

At a local Government level there have been many interventions and changes made to household waste collection services to meet new regulatory requirements. These changes include separate collection of recyclable and organic materials. This paper has used a time series model to quantify the success of interventions introduced by a LA. The case study was a medium sized UK LA, Charnwood Borough Council (CBC), the research analyses monthly data of quantities of recyclates, garden waste for composting and residual waste for landfill disposal. The time series model was validated with a five year data set and used to measure the impacts of the various changes to identify which intervention was the most successful, while controlling for season and number of working days. The results show the interventions analysed both had abrupt and permanent positive impacts on the yield of recyclable materials, and a corresponding negative impact on the residual waste. The model could be added to the National data base to help LAs to compare interventions and to understand which schemes encourage householder participation and improve recycling performance.

Chapter 15 – Construction Waste

Publisher Summary The built environment consumes more natural resources than necessary and therefore generates a large amount of waste. This chapter sheds light on the idea of rethinking construction waste management by reengineering processes and practices to reduce construction waste at source. It examines the concept of waste and definitions. Rethinking waste management in construction requires adopting ‘cyclic’ rather than ‘linear’ approach to design and construction. This requires re-engineering current practice to contribute to a cleaner environment through efficient and cost effective sustainable waste minimization strategies. Following this, the chapter discusses construction waste quantification and source evaluation. It also explores current thinking on construction waste research and appraises the current construction waste management and minimization status in the United Kingdom (UK) in terms of drivers and pressures for change, design and onsite practices, and challenges and enablers. For waste minimization to be effective and self-sustaining, it is important that all stakeholders along the construction supply chain embrace a more proactive approach in dealing with waste. In recognition of the responsibility of the architectural profession, through its leading role in project management and a key player in the construction industry, architects should move beyond the concept of eco-efficiency through bolt-on environmental strategies and strive to adopt eco-effective practices by implementing a holistic approach to design out waste, which will be reinforced in tender documents and implemented during the construction stage, in addition to the capture and dissemination of lessons learnt to inform construction waste reduction baselines and benchmarking in future projects.

Innovation in cleaner production through waste recycling in composites

Purpose – At present Glass Reinforced Plastic (GRP) waste recycling is very limited due to its intrinsic thermoset composite nature and non‐availability of viable recovery options. The purpose of this paper is to assess the recycling potential of GRP waste powder and fibre in concrete, cement and rubber composites.Design/methodology/approach – Extensive laboratory experiments were conducted to examine the suitability of GRP waste in concrete, cement, and rubber composites. GRP waste samples were processed and suitable tests were performed to measure the mechanical properties of the resulting three composites.Findings – The findings of this experimental investigation confirmed that GRP waste can be used as a partial replacement for virgin and raw materials in composites. Furthermore, the addition of GRP waste powder and fibre to composites has the potential to improve their mechanical properties.Research limitations/implications – Results show that the use of GRP waste powder in concrete and rubber composi...

Assessing stakeholders’ perspectives towards the conservation of the built heritage of Suakin, Sudan

The conservation of built heritage is recognized as a vehicle for sustaining local identity and a powerful instrument for urban regeneration. The problem of how to engage local culture in this process, however, has received comparatively little attention, despite the recognition of ‘stakeholders’ and the importance of their involvement. This research examines how collaboration between stakeholders might be established to conserve and thus help regenerate the historic and largely abandoned port town of Suakin. Semi-structured interviews were conducted with representatives of Suakin’s stakeholder groups and supported through archival analysis and observational studies. The intention was to explore the stakeholders’ views of the ‘conservation drivers’, ‘conservation practice’, and ‘conservation challenges and enablers’ affecting Suakin. The stakeholders’ response provides a preliminary status to the various perspectives concerning the conservation of Suakin’s built heritage. The findings identify a number of major issues impacting Suakin’s conservation and reveal a potential for implementing a comprehensive and inclusive conservation approach. The research establishes the case for further research to determine best methods to enable stakeholders to collaboratively address the issues impacting Suakin’s conservation. This approach to stakeholder involvement represents a new step towards the conservation of Suakin and a new contribution towards the conservation process.

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.

Is the Recession Jeopardizing the 2016 Zero Carbon Homes Agenda in England

It is widely acknowledged that the UK building sector is one of the key contributors to carbon emissions, as it is accountable for around 50% of carbon emissions, 27% of which are a product of domestic building construction and operation. As a result, the UK government announced that all new houses are to be zero carbon by 2016. However, the current recession has left the UK construction industry facing its toughest challenges for a generation with the housing sector among those to have sustained the worst damage. Indeed, recent figures reveal that housing orders in the UK were down 30%, amounting to an overall 18% yearly decrease. Hence, a quantitative methodology, consisting of a questionnaire survey sent to 100 UK architects specializing in residential design, was adopted in this research to investigate the effect of the current recession on zero carbon housing design practices in the UK. Results indicate that certain types of clients have been considerably affected more than others; with particular reference to large house builders, who appear to have suffered the most. Additionally, it appears that for many architectural practices, sustainability is no longer as important as making a profit; and for the majority of participants, the zero carbon housing agenda is not a design priority. However, a number of the problematic sustainable design issues identified during the course of the research were not exclusively as a result of the recession. Considerable difficulties had been experienced by the majority of architects concerning the lack of clarity and interpretation of the legislation surrounding low and zero carbon housing design. It is interesting to note, however, that the associated financial impact of zero carbon housing construction preceded the onset of the current recession; with particular challenges faced as a result of the legislative requirement to use onsite micro renewable energy solutions. The participating architects went further to argue that such strategies are generally considered to be too expensive, ineffective and under-developed to be the primary energy source for new housing developments.

An investigation of design waste causes in construction

The construction, demolition and excavation waste arising in the UK is estimated at 109 million tonnes per year. Much had been published on ways to improve on-site waste management and recycling activities but very few attempts made to address design generated waste. This paper examines previous studies on architects’ approach towards construction waste minimisation; and by means of a postal questionnaire sent to the 100 top UK architectural practices, investigates: the origins of design waste; waste minimisation design practices in the UK; and barriers to design out waste. The findings reveal that architects consider 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 and attitudes towards waste minimisation are seen as disincentives to a proactive and sustainable implementation of waste reduction strategies during the design process.