Conference papers by Waqas Ahmed Mahar
CISBAT 2021, 2021
Oasis settlements are the most common form in the Saharan regions of North Africa, identified by ... more Oasis settlements are the most common form in the Saharan regions of North Africa, identified by a strong harmony between urban forms and palm groves, which present the economic capital for these regions. On the other hand, these oases are significantly growing and impacting people’s livelihood and thermal well-being, especially during the summer season. This study aims at first to identify the close correlation between cultivated area (palm grove) and the built-up area throughout the Tolga Oases Complex in Algeria, which is recognised by its palm groves and well-known as one of the largest oasis settlements of the Saharan regions in North Africa. Furthermore, the current work assesses the impact of palm groves by investigating the ‘oasis effect’ on the thermal heat stress levels during July and August daytime hours within nine conducted stations.
1st International Conference on Science, Engineering and Technology (ICSET-2021), 2021
The vegetation patterns, woodlands, agricultural lands, gardens, forests, parks, wetlands and gre... more The vegetation patterns, woodlands, agricultural lands, gardens, forests, parks, wetlands and green belts play a significant role in benefitting the ecological impact and social cohesion. It also maintains the balance between natural and built environments. In recent decades, it has been examined that green spaces in urban areas are quickly vanishing and destruct at an alarming rate. Studies discovered that the fast urbanization trend has brought rapid change in cities and converted them into mega structures resulting in excessive destruction of green spaces. In the climate context, the vegetation cover of urbanized cities significantly impacts diminishing high temperature, decreasing air quality, retaining carbon dioxide from the air, subsiding particulate matter, and retaining smog. It is therefore helpful for achieving sustainable development objectives. This study refers to the urban green spaces and their relationship to the environment and sustainability of Multan city, the largest city and an urban hub of Southern Punjab. The city witnesses the most extreme temperature and is known for sweltering summers and moderate to cold winters. This research investigates the abandoned, deteriorating, proposed and existing urban green spaces in Multan from 1988 to 2020. The study further emphasizes the role of urban green spaces in sustainable urban development. The primary data is collected from the municipal corporation, development authority, satellite images, and meteorological data to assess the urban green spaces, their decline over time and climate effects. The questionnaire and interviews were conducted to collaboratively analyze quantitative and qualitative data through participatory research investigation with local authorities, academic experts, researchers, stakeholders, and communities. The results are examined, and mitigation measures are suggested to regenerate the urban open spaces that are the service provider of the ecological impact to contribute to sustainability and rejuvenate the city's environment.
Proceedings of Building Simulation 2019: 16th Conference of IBPSA, 2019
Building on rooftops has been evident in many European cities. However, there is no specialized c... more Building on rooftops has been evident in many European cities. However, there is no specialized code providing guidelines to achieve high performance roof stacking construction. Accordingly, we aim to support the decision-making on cost-optimal zero-energy roof stacking when selecting glazing parameters. A reference model for a passive house made of timber construction has been developed. A set of variables have been identified with definitive ranges based on previous literature and the available materials in the Belgian market. Then, the objective functions for energy and cost have been defined for the sensitivity analysis. Finally, sensitivity analysis has been conducted, in which variables are evaluated individually based on their significance on energy consumption and cost has been.
AIP Conference Proceedings, 2019
The household sector in Pakistan became the largest consumer of electricity which is responsible ... more The household sector in Pakistan became the largest consumer of electricity which is responsible for more than 51% of the national consumption. The Building Energy Code of Pakistan was developed in 1990, yet the institutional setup regarding energy efficiency & conservation is inadequate. There is lack of experts and implementation of policies at national and provincial level. The study aims to explore the energy efficiency and conservation policies in Pakistan and their impact on reducing household energy consumption. The issues related to the implementation of policies across the country have been further discussed. The paper provides an overview of the energy sector and its challenges related to residential buildings. Energy policies, standards and literature related to building sector were analysed and discussed with the experts. Moreover, suggestions and recommendations are made for the possible solutions and improvement of the existing situation.
Global energy demand is increasing with the rapid urbanization, development, usage of new technol... more Global energy demand is increasing with the rapid urbanization, development, usage of new technologies and expansion of users' net. Many developing countries are facing energy crisis including Pakistan, where energy infrastructure is old and energy sector is facing challenges of supply, demand and distribution. Considering the situation, renewable energy technologies are used across the country including Balochistan province to solve the energy problem. Renewable energy sources, especially solar and wind energy are getting more popular in the province. This paper provides the overview of existing practices of using RE technologies in Balochistan. Moreover, the paper presents the prospects and challenges regarding RE technologies, institutional setup and organizations involved for the dissemination of knowledge and skills regarding RE. In the end, some suggestions are given for effective planning, improvement and use of RE technologies.
Since last several years Pakistan is facing energy crisis which leads to power-cuts across the co... more Since last several years Pakistan is facing energy crisis which leads to power-cuts across the country resulting serious disturbance in everyday life. However, residential buildings use more than half of the energy and its demand and usage is continuously increasing. Quetta is the 10 th largest city of Pakistan and its urban population is increasing at a high rate. The climate of Quetta is mild to extreme cold in winter and hot in summer which need more heating and cooling for optimal thermal comfort in houses. Energy usage of a household do not only depend on the performance of the building, heating, and cooling systems but also on the life style of the residents. The chosen typology is reinforced cement concrete houses, which is very common and widespread across the country. There is no policy or measures taken at the authority level and most of the houses are not designed by professionals, therefore, the existing houses do not provide optimal indoor thermal comfort. The study consists the monitoring of indoor climate, interviews, and questionnaire. The thermal comfort level was quantified based on the monitored data, and the interviews and questionnaire helped to understand the comfort perception, energy consumption behaviour and life style of the residents. The results show that residential buildings do not provide optimal thermal comfort and residents use active systems to improve indoor thermal comfort which leads to increase in energy usage.
1st International Conference on Advances in Engineering & Technology (ICAET 2018), Quetta, Pakistan, 2018
Every year disasters affect hundreds of millions of people globally causing damage that can take ... more Every year disasters affect hundreds of millions of people globally causing damage that can take years to recover from. The process of rebuilding and re-establishing is vitally important to the successful continuation of life, industry and growth of affected societies and communities. Besides human casualties one of the most visible and striking effects of any major disaster is the destruction of houses. Construction of houses will be a major activity in the reconstruction phase of a disaster. The impact of disasters caused by natural hazards such as earthquakes can have serious consequences. Vulnerable populations are faced with unforeseen hardships, misery, and death if their houses and buildings collapse, and supporting infrastructure is severely damaged. Awaran District, Balochistan is one the least developed areas of Pakistan with very low Human development index (HDI). In 2013, an earthquake of Mw 7.7 occurred in the region, causing damage to the houses and human lives. The study covers the findings of the field survey for the damages occurred to the adobe houses in Awaran due to earthquake and analyse the causes of failure of the structures. It further suggests the design strategies and measures for the mitigation and prevention against these damages in order to decrease the loss to housing stock and lower the risks to human life due to failure of structures during earthquake.
Housing plays an important role in human life and in our society. Housing has a great social and ... more Housing plays an important role in human life and in our society. Housing has a great social and economic impact on our lives and the way we live. It has direct and immediate effect on health, education, economy, environment, political and social life of any society. In today's technologically advanced world, the quality of housing and its maintenance in a liveable condition yet remains a challenge in many parts of the globe. This study identifies the various types of structural defects present in the residential buildings of Quetta city. The data was collected from selected areas of the city using questionnaire, physical identification survey, and conducting interviews based on the fundamental knowledge of structural defects and their effects on buildings. It was found that houses in Quetta cantonment area possess the highest number of structural defects followed by Pashtoonabad area. Apart from identifying the most affected area, an overall state of the residential buildings in Quetta city regarding structural integrity was also determined. Since, the city of Quetta is in earthquake zone, it is very important that these types of structural defects should be avoided in future residential buildings and necessary maintenance should be carried out in existing houses to avoid any serious damages to houses and loss of human lives due to the occurrence of any possible disaster.
ENHR 2017 Conference, Tirana, 2017
The province of Balochistan is one of the least developed areas of Pakistan, facing problems of e... more The province of Balochistan is one of the least developed areas of Pakistan, facing problems of energy shortage and rapid urbanization. On the other side the region has great potential for renewable energy sources and the development of sustainable housing concepts. However, a first barrier is the lack of data on the existing housing stock. This paper will discuss the methodology and results of collecting housing data in this context for Quetta city. Considering unsatisfactory law and order situation, a survey was conducted to identify safe areas for housing survey. More areas were included to make the survey more representative. In total 215 houses in 32 residential areas were then surveyed. It is found that housing in Quetta can be divided in 3 main types; i.e. R.C.C frame, brick masonry and sundried bricks and that the energy consumption is mainly determined by area of the house and household size.
Talks by Waqas Ahmed Mahar
3rd Young Researchers Overseas Day, Royal Academy of Overseas Sciences (RAOS), Belgium, 2018
A building must be energy-efficient and provide comfortable indoor environment to the residents. ... more A building must be energy-efficient and provide comfortable indoor environment to the residents. The Building Energy Code of Pakistan (BECP) only focuses on commercial buildings. In today’s scenario a standard must include the context and climate considerations. The aim of this study is to improve indoor thermal comfort of free-running houses in Quetta, Pakistan and raise the awareness of builders about climate sensitivity.
Household sector in Pakistan consumes more than half of the energy. Quetta is the capital and the... more Household sector in Pakistan consumes more than half of the energy. Quetta is the capital and the largest city of Balochistan province, Pakistan. The city is facing problems due to increasing population, and shortage of energy. The existing houses are not providing optimum thermal comfort to the residents and the residents are using mechanical methods for achieving comfort in their houses which increase the usage and the demand of energy. There is strong need to develop and adopt the climate responsive strategies to achieve thermal comfort by using minimum energy and reducing the environmental impact. The aim of this PhD is to develop climate responsive design strategies for the improvement of indoor thermal comfort of free running houses at Quetta by providing cost effective, low-tech, energy efficient and locally acceptable solutions. A housing survey was conducted to characterize the existing houses in Quetta and identify the common housing types. The most common housing typology i.e. houses with reinforced cement concrete (R.C.C) structure were selected for the further analysis. Indoor climate of 10 houses was monitored and structured interview was conducted to get insights about the thermal comfort level and perception of the residents. It was found that houses mainly face daily 4-8h electricity outage hours both in summer and in winter season. Residents are less satisfied with the cost of energy compared to the consumption. However, they seem relatively more satisfied with the prices of natural gas than electricity. The houses are very warm in summer and cold in winter. The situation leads to more use of mechanical systems to obtain thermal comfort. The monitored climate data shows that indoor temperature is high is summer and low in winter while the humidity level is generally low in both seasons. The increase in temperature decreases the humidity level making indoor environment more uncomfortable.
Doctoral Seminar on Sustainability Research in the Built Environment (DS2BE) 2017, 2017
Quetta, the capital of Balochistan province, Pakistan, is facing problems due to increasing popul... more Quetta, the capital of Balochistan province, Pakistan, is facing problems due to increasing population and shortage of energy and water. The aim of this PhD is to develop a methodology for the design of sustainable houses in Quetta, taking into account the best possible solutions for the energy and water shortage and maximizing the use of local materials.
In the first phase of the PhD, an inventory of the existing housing stock is made. Due to the unsatisfactory law and order situation, a safety questionnaire was distributed online to identify the safe areas for the housing survey. The areas identified as safe were complemented with areas in which university students and staff, who helped with the housing stock survey, live, to get more representative data. Then 215 houses were surveyed in 32 residential areas of Quetta by filling in the questionnaire, taking pictures and drawing sketches.
In the survey, demographic information, data on the energy consumption and systems, construction types and material use is gathered. Three common structural systems are identified, i.e. R.CC frame, brick masonry and sundried bricks. For each structural system, the main materials for the construction and finishing of walls, roof and floor are inventoried.
The most common housing type is R.C.C frame structure for all income groups, with a plot size depending on household size and income. In phase-II, this type of houses will be further analyzed in detail for their energy performance, environmental impact, construction patterns, water and energy consumption and the household characteristics. In phase-III, a sustainable house concept has to be developed taking into account all the information collected in phase-I & II. It will be further validated by simulations of energy, comfort and water performance and discussion with experts and future occupants.
Thesis Chapters by Waqas Ahmed Mahar
University of Liège, Belgium, 2021
Pakistan is facing a severe energy crisis which results in power cuts across the country. This si... more Pakistan is facing a severe energy crisis which results in power cuts across the country. This situation seriously disturbs everyday life, business, and economic activities. The household sector in Pakistan is the primary consumer of electricity. A reasonable sum of this electricity is used for heating and cooling residential buildings, which can be reduced by adopting passive design strategies. This PhD research aims to provide informed decision support to design and construct climate-responsive houses in the cold semi-arid climate of Quetta, considering the appropriate and locally adapted low-tech solutions to improve residential buildings' indoor thermal comfort. Firstly, a literature review was done to understand the existing housing, comfort, and energy situation in Pakistan. An inventory of the current housing stock was then created to identify housing characteristics, construction types, and materials. The most common housing type was analysed for indoor climate, including monitoring indoor temperature and humidity, comfort perception and energy usage behaviour. Semi-structured interviews were conducted with the residents to get insights on their comfort perception, clothing, behavioural adaptations, lifestyle etc. Then a benchmark study was performed by selecting the most representative house. The representative house's virtual model was analysed using dynamic simulation and calibrated based on actual monitored data. Four comfort models were compared to identify the best fit-t-context model. A parametric analysis was done using passive design strategies to improve indoor thermal comfort. A sensitivity analysis of 21 design variables was performed to identify the most influential passive design strategies, which can be used in the climate of Quetta. A materialization survey was done to determine the locally available and manufactured materials. Based on this PhD research analysis and findings, a prescriptive guide was developed to provide informed decision support for architects to design comfortable and climate-responsive houses. The prescriptive guide was then tested and validated. A usability test was performed among the architects and architecture. The results show that the prescriptive guide provides enhanced decision support compared to the Building Code of Pakistan. In the end, recommendations are made for the regulators and further research.
Defects are seen in many newly constructed houses around the world caused of various flaws and la... more Defects are seen in many newly constructed houses around the world caused of various flaws and lacking such as design defect, construction, execution of work, material’s performance/selection etc. As building façade is exposed to the weather and environment so that defects can easily occur on it, especially in the tropical region. Studies have proved that the common defects occur on building facades damages the beauty and aesthetic view of the building. This research is designed to identify the defects on building facades, their position and magnitude. Therefore to achieve these objectives a physical survey is conducted within the selected housing area “Desa Bakti” and mapping is done according to the observation by using computer aided drawing tool and then results are calculated to identify the total affected area. It is to add that no special investigation or scientific method was used for this research except the physical observation method. From the data collection, it was found that building facades of several housing units were affected by common defects. These defects might not be of severe nature which may cause damages to stock and human life but it is more to aesthetic defect and still costs good amount to fix. No cracking or structural failure was noticed during the survey and the focus was only given to defects on building facades. It was found that most of the defects on building façades were located near the floor area or at lower level of façade which shows that these defects are reachable and can be easily fixed.
Drafts by Waqas Ahmed Mahar
Sustainable Building Design (SBD) Lab, University of Liège, 2018
The report is a part of the PhD project entitled “Methodology for the design of climate responsiv... more The report is a part of the PhD project entitled “Methodology for the design of climate responsive houses for optimised thermal comfort in Quetta, Pakistan” being carried out at University of Liège, Belgium. The aim of the project is to improve indoor thermal comfort of free-running houses in Quetta and raise the awareness of builders about climate sensitivity. The present findings are based on the monitoring of indoor climate, survey questionnaire and the interviews of the residents living in the houses made of reinforced cement concrete (RCC) structure. We aim to provide the readers with insights and perspectives on the existing houses, their comfort performance, comfort perception and understanding of the residents and the use of mechanical methods to optimise thermal comfort in RCC houses in Quetta, Pakistan.
This report is a part of the PhD project entitled “Methodology for the design of climate responsi... more This report is a part of the PhD project entitled “Methodology for the design of climate responsive houses for optimized thermal comfort in Quetta, Pakistan” being carried out at University of Liège, Belgium. The aim of the project is to improve indoor thermal comfort of free running houses in Quetta and raise the awareness of builders about climate sensitivity. The present findings are based on the housing survey and the available literature regarding housing and existing infrastructure of energy, water & waste systems in Quetta, Pakistan. We aim to provide the readers with insights and perspectives on housing construction, conditions and characteristics in Quetta, Pakistan and an overview of existing infrastructure regarding energy, water & waste systems.
Papers by Waqas Ahmed Mahar
Architecture and Engineering, 2024
Introduction: Buffer zones in the context of World Heritage sites play an important role in prote... more Introduction: Buffer zones in the context of World Heritage sites play an important role in protecting historic monuments and buildings, as well as their adjacent conservation areas, from disruptions caused by urban development. However, properties within the boundaries of buffer zones may be subject to legislative limitations and restricted construction regulations. This may affect the market value of these properties and make them unfavorable for public and private investors. Purpose of the study: The study aims to critically analyze the impact of buffer zone policy on urban development, specifically on the land value and the quality of the built environment in the context of World Heritage sites. The case study for this research is Kampung Jawa (KJ) in the World Heritage City of Melaka, Malaysia. Methods: A combination of qualitative and quantitative methods was used to conduct this research. The required data was gathered through direct observations, semi-structured and informal interviews with stakeholders and local authorities, as well as a review of available statistical data and maps. A site observation and a questionnaire survey were conducted to examine all the structures in KJ. Results: The research findings revealed that the low land value of buffer zones might be caused by several context-specific conditions, eventually turning them into greyfields. The research recommends a design solution for the area. The research also suggests that certain decisions at the policy-making level, including the involvement of all stakeholders, can be the key to improving the land value and property market within buffer zones.
CivilEng, 2024
The demand for lightweight aggregates in concrete compositions for diverse structural and non-str... more The demand for lightweight aggregates in concrete compositions for diverse structural and non-structural applications in contemporary building construction has increased. This is to achieve a controllable low-density lightweight concrete, which reduces the overall structural weight. However, the challenge lies in achieving an appropriate strength in lightweight concrete while maintaining a lower unit weight. This research aims to evaluate the performance of lightweight concrete by integrating expanded polystyrene (EPS) as a partial replacement for coarse aggregate. Test specimens were cast by blending EPS with coarse aggregate at varying proportions of 0%, 15%, 30%, and 45%, while maintaining a constant water-to-binder ratio of 0.60. To enhance the bonding and structural capabilities of the proposed lightweight concrete mixes, reinforcement with 2% and 4% steel fibers by volume of the total concrete mix was incorporated. Silica fume was introduced into the mix to counteract the water hydrophobicity of EPS material and enhance the durability of lightweight concrete, added at a rate of 10% by weight of cement in all specimens. A total of 60 samples, including cylinders and beams, were prepared and cured over 28 days. The physical and mechanical properties of the lightweight EPS-based concrete were systematically examined through experimental testing and compared against a standard concrete mix. The analysis of the results indicates that EPS-based concrete exhibits a controllable low density. It also reveals that incorporating reinforcement materials, such as steel fibers, enhances the overall strength of lightweight concrete.
Sustainability, 2024
Improving urban walkability in the face of climate change is a critical challenge for urban desig... more Improving urban walkability in the face of climate change is a critical challenge for urban designers. Street design strategies can mitigate heat stress and enhance pedestrian livability. Most previous studies conducted in hot climates recommend adopting deep canyons to improve summer conditions, overlooking the potential improvement of wide streets as essential structural elements of the urban fabric. This study was conducted in Biskra city, southern Algeria, where several mitigation strategies were applied to ‘Emir Abdelkader Boulevard’, as the main structural street inside the city, to create an optimal street model for arid climates. Five scenarios were developed based on three criteria: (Sc1) asymmetric profile northeast side (NES) > southwest side (SWS); (Sc2) asymmetric profile SWS > NES; (Sc3) cool paving; (Sc4) horizontal shading; and(Sc5) shading with a linear tree arrangement. ENVI-met software version 5.1.1 and the RayMan model were used to estimate the local climate conditions and outdoor thermal comfort levels based on the physiological equivalent temperature (PET). All scenarios reduced PET values across the street, with optimal reductions of −2.0 ◦C, −3.1 ◦C, −1.3 ◦C, −1.7 ◦C, and −1.2 ◦C in Sc1, Sc2, Sc3, Sc4, and Sc5, respectively. Concerning pedestrian areas, the optimal results durations were at the southwest side below the arcades’ sidewalks during peak hours: Sc2, Sc3, Sc4, Sc5 (2.2 ◦C–3 H, 2.3 ◦C–3 H, 2.4 ◦C–3 H, 2.5 ◦C–2 H). Sc1 performed best during daytime hours on the northeast side. The utilizing of these results can strongly help urban planners and landscape architects in creating climate-responsive streets that enhance citizens’ quality of life.
Journal of Art, Architecture and Built Environment
Many studies have explored outdoor thermal comfort during the last several years, ever since it h... more Many studies have explored outdoor thermal comfort during the last several years, ever since it has been strongly related to human health and well-being. The physiological equivalent temperature (PET) is one of the most commonly used thermal comfort indexes. It has been approved and applied within different urban spaces and climates. This study is a comparative research that explored the importance of using mean radiant temperature (Tmrt) in PET assessment by employing two different methods. The first method was used to calculate PET based on three measured variables including relative humidity, wind velocity, and air temperature. RayMan software was utilized to perform the calculations. The second method was used to calculate PET by combining Envi-met and RayMan. Envi-met allowed four sets of calibrated data, including the data of air temperature (Ta), wind velocity (Wv), relative humidity (RH), and mean radiant temperature (Tmrt). RayMan software used the calibrated results to cal...
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Conference papers by Waqas Ahmed Mahar
Talks by Waqas Ahmed Mahar
In the first phase of the PhD, an inventory of the existing housing stock is made. Due to the unsatisfactory law and order situation, a safety questionnaire was distributed online to identify the safe areas for the housing survey. The areas identified as safe were complemented with areas in which university students and staff, who helped with the housing stock survey, live, to get more representative data. Then 215 houses were surveyed in 32 residential areas of Quetta by filling in the questionnaire, taking pictures and drawing sketches.
In the survey, demographic information, data on the energy consumption and systems, construction types and material use is gathered. Three common structural systems are identified, i.e. R.CC frame, brick masonry and sundried bricks. For each structural system, the main materials for the construction and finishing of walls, roof and floor are inventoried.
The most common housing type is R.C.C frame structure for all income groups, with a plot size depending on household size and income. In phase-II, this type of houses will be further analyzed in detail for their energy performance, environmental impact, construction patterns, water and energy consumption and the household characteristics. In phase-III, a sustainable house concept has to be developed taking into account all the information collected in phase-I & II. It will be further validated by simulations of energy, comfort and water performance and discussion with experts and future occupants.
Thesis Chapters by Waqas Ahmed Mahar
Drafts by Waqas Ahmed Mahar
Papers by Waqas Ahmed Mahar
In the first phase of the PhD, an inventory of the existing housing stock is made. Due to the unsatisfactory law and order situation, a safety questionnaire was distributed online to identify the safe areas for the housing survey. The areas identified as safe were complemented with areas in which university students and staff, who helped with the housing stock survey, live, to get more representative data. Then 215 houses were surveyed in 32 residential areas of Quetta by filling in the questionnaire, taking pictures and drawing sketches.
In the survey, demographic information, data on the energy consumption and systems, construction types and material use is gathered. Three common structural systems are identified, i.e. R.CC frame, brick masonry and sundried bricks. For each structural system, the main materials for the construction and finishing of walls, roof and floor are inventoried.
The most common housing type is R.C.C frame structure for all income groups, with a plot size depending on household size and income. In phase-II, this type of houses will be further analyzed in detail for their energy performance, environmental impact, construction patterns, water and energy consumption and the household characteristics. In phase-III, a sustainable house concept has to be developed taking into account all the information collected in phase-I & II. It will be further validated by simulations of energy, comfort and water performance and discussion with experts and future occupants.