An overview of recent research related to building renovation has revealed that efforts to date do not address sustainability issues comprehensively. The question then arises in regard to the holistic sustainability objectives within building renovation context. In order to deal with this question, the research adopts a multi-dimensional approach involving literature review, exploration of existing assessment methods and methodologies, individual and focus group interviews, and application of Soft Systems Methodologies (SSM) with Value Focused Thinking (VFT). In doing so, appropriate data about sustainability objectives have been collected and structured, and subsequently verified using a Delphi study. A sustainability framework was developed in cooperation with University of Palermo and Aarhus University to audit, develop and assess building renovation performance, and support decision-making during the project’s lifecycle. The paper represents the results of research aiming at addressing sustainability of the entire renovation effort including new categories, criteria, and indicators. The developed framework can be applied during different project stages and to assist in the consideration of the sustainability issues through support of decision-making and communication with relevant stakeholders. Early in a project, it can be used to identify key performance criteria, and later to evaluate/compare the pros and cons of alternative retrofitting solutions either during the design stage or upon the project completion. According to the procedure of the consensus-based process for the development of an effective sustainability decision-making framework which was employed in this study, the outcome can also be considered as an outset step intended for the establishment of a Decision Support Systems (DSS) and assessment tool suited to building renovation context.
In order to arrest the incidence of global warming brought about by the emission of greenhouse gases notably CO2 into the atmosphere, the use of materials that can substitute the material responsible for greenhouse gases is being promoted world-wide. One of these is rice husk ash (RHA) which has been found suitable by researchers to partially replace Portland cement in the production of concrete. This paper presents a comprehensive and up-to-date review of the work of numerous researchers on structure and properties of concrete containing rice husk ash (RHA) as partial replacement of ordinary Portland cement. Some of the findings are: (i) controlled incineration is required to produce RHA with structure that can result in structural concrete, (ii) the use of RHA resulted in increased water demand, (iii) up to 10% cement replacement with RHA will result in strength development comparable to the control specimens, and (iv) the use of RHA in concrete result in impervious RHA-concrete microstructure to agent of degradation like, sulphate attacks, chloride ingress, etc., as well as good shrinkage properties, and thus produce durable concrete when used. However, some areas such as the bending and shear responses (and allied properties) of reinforced concrete slabs and beams with RHA are presently not yet covered by researchers; they are therefore recommended for future investigation.
Disposal of huge amount of discarded waste materials like plastic, polythene bags, bottles, rubber tyres etc, which are generated in huge quantity and causes environmental hazards after their disposal. Present study attempts to utilize these waste materials as partial replacement of bitumen to develop a modified binder, for making bituminous concrete mix. To simulate with the field conditions, ‘Marshall Stability Analysis’ was performed on the samples prepared by partially replacing ‘Optimum Bitumen Content’ with waste plastic (4%, 6%, 8% and 10%) and crumb rubber (5%, 10% and 15%). Experimental results demonstrate that partial substitution of bitumen with waste plastic results up to 16% increment in strength whereas with rubber material, about 50% increment in strength was observed as compared to the conventional mix (CM). Laboratory testing results indicate that by using waste materials, bituminous concrete of required strength and density can be obtained and an environment friendly green pavement can be prepared with less material cost.
Decision making on buildings after the earthquake have always been a great concern of scientists. Safety concerns, possibility of using the building, repairing the building, and the rate of damage are some of the most vital factors that needs to be paid attention in immediate decision makings of the buildings. In order to determine the level of damage in the buildings, the maximum displacement of stories is one of the most important parameter that needs to be investigated. In this paper, a concrete frame with shear wall containing 4-stories and 4-bays has been designed for acceleration records of 0.1g to 1.5g and the rate of damage is determined. The total of 450 data with 6 input variables and one output variable is produced. The input parameters are defined as frequency, Vs, Richter, the distance from the earthquake epicentre (DEE), PGA, and acceleration, and the output parameter is defined as drift. With respect to this data set, three different data-driven models, i.e. Artificial Neural Network (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS), and Multiple Linear Regression Model (MLR) are used to predict the displacements. Results indicate that Both the ANN and ANFIS model show great accuracies in estimating the displacements in concrete frame with shear wall. On the other hand, MLR model did not show acceptable accuracy in the same estimation purposes. Finally, the sensitivity analysis was performed on the data set and it was observed that the accuracy of the predictions highly depends on the number of input parameters. In other words, increasing the number of input parameters would result in the increase in the accuracy of the final prediction results.
An attempt has been made to study the subsurface groundwater discharge (SGD) in the coastal Cuddalore region of south east India. Measurement for Radon, water level, Electrical Conductivity (EC) and pH in surface water for a total of twenty hours by hourly interval has been attempted and further correlated with tidal values calculated by WX Tide 32 software. The SGD measurements were made by using a modified seepage meter. The study reveals a match with water level variation and tide with minor variation due to influx of surface water. Saline discharges, fresh groundwater discharges and surface water mixing processes were identified along the coast. Lower SGD (37.24–79.16cm/day) was observed during fresh groundwater discharge.
In this paper is presented an approach for landfill leachate treatment using enhanced natural evaporation. Experimental set up considered using a greenhouse pilot prototype placed into the municipal landfill of Puebla city, México. The greenhouse was built with a basement surface enough to place 9 trays with leachate. Treatment follow up was done through the following parameters: air temperature inside and outside the greenhouse; leachate temperature at surface and middle liquid height. Results of the first set of experiments defined a minimal initial liquid height of 20% in respect to the tray height; the 2nd set allowed defining optimal evaporation rate conditions evaluated in respect of a tray placed outside, considered as reference of 100% efficiency (blank), obtained results showed that morning and night processes provided efficiencies up to 2 times the reference; otherwise, afternoon measurements showed similar temperature values inside and outside. In general collected data at winter season provided efficiencies between 82% and 147%, in periods of 24h, it was observed that higher liquid reductions took place at North, and lower ones at the South positions. Based on these results it was proposed a 20days experiment, using stagnant (E) and recharge (R) conditions referred to the blank (L), the R process showed greater efficiency (168%) than the stagnant one (158%). Leachate chemical characterization indicates that pH is highly stable; while total solids, chemical oxygen demand, sulfate and chloride exhibit an increase in concentration reaching values of 1.2–2.5times the initial concentration, phosphate was the only parameter exhibiting a decreasing trend ending with 40% of its initial concentration.
Climate change is expected to increase both the magnitude and frequency of extreme precipitation events, which may lead to more intense and frequent river flooding. This study aims to assess the flood hazard potential under climate change scenarios in Yang River Basin of Thailand. A physically-based distributed hydrological model, Block-wise use of TOPMODEL using Muskingum-Cunge flow routing (BTOPMC) and hydraulic model, HEC-RAS was used to simulate the floods under future climate scenarios. Future climate scenarios were constructed from the bias corrected outputs of three General Circulation Models (GCMs) for 2020s, 2050s and 2080s. Results show that basin will get warmer and wetter in future. Both the minimum and maximum temperature of the basin is projected to increase in future. Similarly average annual rainfall is also projected to increase in future, higher in near future and lower in far future. The extreme runoff pattern and synthetic inflow hydrographs for 25, 50 and 100year return flood were derived from an extreme flood of 2007 which were then fed into HEC-RAS model to generate the flood inundation maps in the basin. The intensity of annual floods is expected increase for both RCP 4.5 and 8.5 scenarios. Compared to the baseline period, an additional 60km2 area of basin is projected to be flooded with the return period of 100years. The results of this study will be helpful to formulate adaptation strategies to offset the negative impacts of flooding on different land use activities in Yang River Basin.
Every assessment of urban spatial structure requires determining the importance of activity centres. This paper gives an attempt to analyse the spatial and temporal changes experienced by major activity centres in the Sydney metropolitan area. The objectives of the research were first, to explore the role of main activity centres on the distribution of job opportunity across the metropolitan area, second to find out whether or not these key activity centres were influential in making the Sydney’s urban structure more poly-centric rather than being a mono-centric. It also estimates how accessible these activity centres are for the workforce and what their corresponding labour catchment areas are. Eleven activity centres were chosen based on the preliminary analysis of Sydney’s planning and development documents and exist evidences on living and working spots. A number of analysing techniques such as mapping of journeys to work in these centres, influence circles of centres, employment preference functions, and tabular data on the levels of employment were applied. The results of the analysis show that apart from the CBD, North Sydney, Parramatta and Inner City the remaining activity centres appear to exert slight impact on employment distribution across the metropolitan area. There does not seem to be evidence for a significant polycentric structure in Sydney metropolitan area in regarding with employment recruitment, seeking and retention.
This paper evaluates the economic, environmental, and social benefits of large-scale energy efficiency programs for new and existing buildings in Qatar. Using data obtained from detailed energy audits, several proven energy efficiency measures have been analyzed through optimized based analysis to assess their impact on the energy performance for both new and existing buildings in Qatar. Moreover, a bottom-up analysis approach is considered to quantify the multiple benefits for implementing large-scale building energy efficiency programs for the building stock in Qatar. In particular, a more stringent energy efficiency code for the new constructions and three energy retrofit levels for the existing buildings are considered in the analysis. A novel macro-economic analysis using the concept of energy productivity is used to assess the cost-benefit of large-scale energy efficiency programs in Qatar. It is determined that the implementation of a government funded large-scale energy retrofit program for the existing building stock is highly cost-effective in Qatar. In particular, it is found that a large-scale energy efficiency retrofit program of existing buildings can provide a reduction of 11,000 GWh in annual electricity consumption and 2500 MW in peak demand as well as over 5400 kilo-ton per year in carbon emissions. In addition, over 4000 jobs per year can be created when this large-scale energy retrofit program is implemented over 10-year period.
In recent years, there is a renewed interest towards the passive cooling features of ancient building architectures, which are cost effective, eco-friendly and best suited for the local climate. On the other hand, the modern construction materials, such as cement and steel, are highly durable. Thermal comfort of eight vernacular buildings that use modern construction materials to improve the structural durability was monitored in July 2014. The buildings are located in Hyderabad, India. They have many passive cooling features that include air cavities in the structures to reduce heat transfer, high thermal mass to reduce temperature fluctuation and induced ventilation to remove heat from the indoor. All the passive cooling features investigated were found to have an appreciable influence on the thermal comfort of the indoor space. The ventilated air gaps in the roof reduced the average temperature of the roof interior surface by 1.2°C. The diurnal temperature fluctuation of the indoor air reduced by 0.9°C in a building with a higher thermal mass compared to a building with thin walls and roof. All the eight buildings were found to be comfortable most of the time with a slight discomfort during late night and morning hours. The maximum CO2 recorded was 550ppm. This indicates that the buildings were adequately ventilated.
The study examined the factors responsible for the spatial variation in housing quality across the 36 states and the Federal Capital Territory in Nigeria using 33 housing characteristics. The data used are the 2006 Housing Characteristics and Amenities tables which were sourced from Nigeria’s National Population Commission (National Population Commission, 2006). Principal Component Analysis extracted three components. Component 1 accounting for 38% has electricity, water closet toilet, hygienic sources of water and high quality roofing, walling and flooring materials highly loaded on it. Component 2 (31%) comprised inferior walling, roofing and flooring materials, pit toilet, traditional and semi-detached house types, while component 3 (7%) had mainly zinc wall and public toilet highly loaded on it. Using these factor loadings as variables in discriminant analysis, three distinct regions of differing housing quality emerged corresponding to the western, eastern and northern geographical regions of the country with 97.3% of the states correctly classified and with the western (high) and northern (low) states at the opposite ends of the quality scale. It is recommended that non-conforming buildings, particularly, residential, and insanitary environment should be put in check through very strict and proactive enforcement of development control edicts and sanitary laws.
The hedonic pricing model (HPM) technique has been widely adopted for property price appraisal by scholars and professionals in different real estate markets around the world. Despite its popularity in this research domain, the trend of the application of HPM in Nigeria, being the largest economy in Africa, is unknown and has not been documented. This study, therefore, aims to critically review the extant literature of the HPM property price appraisal related articles published in Nigeria. Papers published in this research area were retrieved from online databases and search engines. The authors’ contributions, authors’ affiliations, the focused study areas and the annual publication trend of the articles were reviewed. The first application of HPM in Nigeria was recorded in 1986. Thereafter, there have been fluctuations in the number of annual publications. However, there have been a considerable number of articles published since 2010. The authors have largely focused on the Lagos metropolis property market as a study area. It was also found that most of the authors were university scholars and on the other side, real estate professionals have not contributed significantly to this research topic. In order to achieve a sustainable real estate practice in Nigeria, the gap between theory and practice should be bridged.
High temperatures in urban areas affect the health and wellbeing of urban dwellers. Malacca City has undergone a tremendous growth during the last decades, particularly after its designation as a UNESCO World Heritage Site in 2008. As a result of urban development, two dominant urban configurations were formed in Malacca: the heritage site and contemporary urban areas. This study examines the effects of aspect ratio (H/W) on air temperature in two urban configurations in Malacca. The three-dimensional microclimatic modelling system ENVI-met (version 3.1) was used to simulate the summer time air temperature variation in the typical urban setting of a heritage site and contemporary urban area. Aspect ratio was found to have a considerable influence on the air temperature distribution in both areas. The daytime air temperatures decreased with increasing aspect ratio. The simulation results showed that during the daytime, the heritage site (aspect ratio of 2.6) was warmer than the contemporary urban area (average value of H/W=1.6), and that cooling occurred more quickly in the latter. The results of this study provide useful information for planning, building and modifying urban structures.
Driven by a plethora of external and internal influences, the construction industry has independently embraced lean principles and green initiatives. Prima facie significant synergies have been reported between these two paradigms. It is foreseen that when tapped and adopted in unison, these paradigms may yield additional benefits for the construction projects. This synergy is investigated in this research. Further this study identifies and proposes Building Information Modelling (BIM) as an enabler for gaining lean and green project outcomes. The study uses crisp set qualitative comparative analysis (csQCA) method for exploring the causal combinations of different BIM capabilities and asserts that causal combinations of four BIM capabilities: MEP system modelling, energy and environment analysis, constructability analysis and structural analysis, when implemented on construction projects can lead to lean and green outcomes. With the help of sixteen cases it is shown that adoption of BIM leads to improved project outcomes especially ones targeting lean and green aspects.
During the last few years, an increasing interest has been appeared for earth as a building material. Earth-based materials have been studied because of energy efficiency and ecologically sustainability. The chromite deposits, 10% of the world reserves, are processed in Elazığ Ferrochrome Factory in Eastern of Turkey. Elazığ Ferrochrome slag (EFS) as a by-product of the factory is produced roughly 50,000 tons in a year. The disposal, removal and storage of this by-product is a serious problem. Therefore, the utilization of this waste material in building applications is very important. The aim of this work is to investigate effects of gypsum and EFS additives on mechanical and physical properties of unfired earth brick (UEB) materials in order to assess their potential advantages in building applications. The earth material was characterized by laboratory tests. Four different UEB samples were produced by using different compositions of earth, gypsum, EFS and straw fibers. Compressive strength, water absorption coefficient, drying shrinkage, ultrasonic pulse velocity (UPV) and density of the prepared UEB samples were determined. The experimental findings have showed that the usage of gypsum and EFS in stabilizing process of UEBs was advantageous.
This study specifically looked at total water supply in China, water withdrawal from various sources and various usage of water. From the analysis, it was realized that water supply from the underground source contributes greatly to the total water supply in China, a cubic unit withdrawal in underground water results in about 45% increase in the total water supply. Water from other sources also contributes to the total water supply in China. Water from other sources includes supplies from wastewater treatment, rain collection, seawater desalinization and other water projects. The result shows that a cubic unit increase in withdrawals from other sources results in about 3% change in gross water supply in China. A cubic unit withdrawal of water for industrial use results in about 29% increase in water use in China. For the agriculture sector, the result shows that a cubic unit increase in agriculture usage leads to approximately 67% increase in total water use in China. Water for household consumption, saw a 15% increase in total water usage in China for every cubic unit withdrawal.
This study explores the sense of place in the small coastal Algerian town of Tipaza. The town is famous for its world archaeological sites, but its inhabitants and the local community in general seem to appreciate more its exceptional landscape than the universal archaeological values conferred to it by UNESCO. The particular townscape clearly delimited by the Mediterranean Sea and the Chenoua Mountain seems to have strongly influenced people’s mental images and attachments to their town. Based on the concepts of environmental representation and place attachment, local-community’s sense of place is investigated at three territorial scales: the town centre, the town as a whole and the region. Since the sense of place is defined as a multidimensional attitude including cognitive, conative and affective aspects, the proposed paper examines the socio-cognitive dimension through the structural approach of social representations where shared socio-cognitive meanings are assumed to constitute the central core of environmental representations. On the other hand, the conative component has been investigated through the analysis of expected activities in favourite places. Moreover, place attachment, an affective bond between people and environmental setting, is explored through two sub-concepts: place identity which refers to the cognitive level and place dependence which refers to the conative level. By exploring shared local community’s meanings and their impact on place preferences and appropriation, the research aims at showing the value of townscapes and particularly coastal ones in urban development projects. Natural features such as the sea are powerful landmarks and have strong impact on people’s perceptions of environmental settings.
The importance of local knowledge and traditional practices is now recognized by disaster risk reduction specialists, particularly in the aftermath of the tsunami in the Indian Ocean in 2004. However, these frequently used practices by local populations are not yet recognized by all actors involved in disaster prevention. This research seeks to identify local traditional practices which are connected to hydro-meteorological phenomena and climate change in the coastal areas of the Yucatán Peninsula in the Rio Lagartos Biosphere Reserve. The identification process requires observation, documentation, validation and categorization of local traditional knowledge. The traditional practices (mainly by fishermen as well as some farmers) examined specifically among the coastal populations relate to their habitat, natural resources, and fishing practices. Recognizing and valuing traditional knowledge will help improve resilience to the impact of disasters and the effects of climate change among coastal populations.
The physical form and pattern of built environment in a city is the outcome of prevalent planning and design standards and building regulations. Many common issues of built environment are the consequence of existing building regulations in that settlement as building regulations are borrowed from other cities and adopted from one place to another across the country. Building regulations are mostly specified for various uses and apply to the particular size of a plot in India, generally, irrespective of the shape and topography of the plot. As a result, often while complying with the provisions of one regulation will lead to noncompliance of provisions of other regulations. This further aggravates the problems of noncompliance with the existing building regulations and often results in unauthorized development and enormous environmental impacts. An attempt is made to understand different issues associated with building regulations of Shimla. Further, the effects of plot proportions on the compliance of building regulations are also studied in the case of Shimla, being the largest hilltop town of northern India on ecologically sensitive topography.
