Browsing by Author "Madushika, UGD"

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item: Conference-Full-text
Carbon footprint analysis of construction activities in Sri Lanka: an input-output table
(Faculty of Architecture Research Unit (FARU), 2021-12-03) Gunathilake, S; Ramachandra, T; Madushika, UGD
The construction industry is one of the major contributors that emits carbon into the environment. When considering the carbon emission in the local context, even though there are Input-Output Tables (IOTs) that applies to all types of industries in Sri Lanka, there seems to be limited focuses on IOTs specifically relating to the construction activities which is vital for the need due to its outstanding contribution to the carbon footprint of Sri Lanka. Hence, this study aims to calculate the carbon footprint construction activities in Sri Lanka using IOT with a bottom-up approach. The required data were extracted from published documents of Survey of Construction Industry by Census and Statistics, and The Inventory of Carbon and Energy (ICE) database of UK. Carbon footprint of construction activities were calculated using IOT with a bottom-up approach. The analysis revealed that the road and railway sector have the highest contribution of 48% to the monetary value of the construction industry meanwhile it accounts for 44% of the highest carbon emission to the atmosphere in the year 2020. Subsequently, activities related to non-residential residential, and utilities contribute to 20%, 15%, and 12% of total carbon emission respectively. In terms of construction materials, cement-based activities (59%) were the highest contributor while rubble and metal-based (23%), and iron and steel-based activities (17%) were next level contributors to the carbon emission due to construction. The analysis concluded that the as the initiatives, public sector projects including road and railway sector and utilities should integrate more sustainable construction practices as they are responsible for more than 50% of carbon emission.
item: Conference-Full-text
Economic performance of green walls: A systematic review
(Ceylon Institute of Builders - Sri Lanka, 2022-06-24) Madushika, UGD; Ramachandra, T; Geekiyanage, D; Sandanayake, YG; Waidyasekara, KGAS; Gunatilake, S
Green walls are becoming an interesting solution to address the potential issues due to loss of greenery in the urban built environment. Even though green walls offer numerous benefits, the application pace of this concept seems slow in many parts of the world including Sri Lanka, which could be primarily due to the perception that the construction of green walls may involve additional costs compared to conventional walls and due to lack of awareness of its performance. This has driven the recent researchers to investigate the economic performance of green walls. However, those studies are limited to given local contexts, thus, the knowledge is scattered. Therefore, this paper aims to explore the economic performance of green walls in the global context collectively using a systematic review towards understanding the differences. Filtering the search for the period of 2010 to 2022 offered 15 out of 103 research articles suitable for the analysis. The cost data extracted shows high variability related to different characteristics of green walls, building envelopes, and climatic conditions. According to the review, the maintenance stage accounts for the highest portion of the Life Cycle Cost (LCC) in any type of green wall. The direct green façade is the cheapest option with lowest LCC compared to the indirect and living wall types while the living wall is the expensive type due to presence of more components. The review further confirms that in most instances, the economic benefits of green walls; increase property value, façade longevity, tax incentives, and energy-saving tend to offset the cost of green walls. It is expected that this collective review outcome would better guide the decision-making process of green wall implementation in a given context.
item: Conference-Full-text
Enhancing value engineering application in the Sri Lankan building construction industry : a framework
(2021-07) Sandupama, AVPU; Ramachandra, T; Madushika, UGD
The concept of value engineering (VE) is used to optimise the cost, time, quality, and functional performance toward achieving the best value for client money. However, the application of VE in construction industries is limited as there are differences in the use of the VE concept to developing economies, application of cost-oriented procurement systems, and lack of a practically applicable framework. In the local construction context, VE is practiced in an ad hoc manner. Therefore, the current study aimed to develop a framework including a tailored approach to enhance the VE application in the building construction industry. A qualitative approach was adapted to solicit views of twenty-two (22) construction professionals who involved in the six (6) high-rise building construction projects and practiced the VE concept. Views of professionals were synthesised using content analysis and finally developed a framework including a tailored VE approach. The findings conclude that cost and time as the main value criteria which motivate the VE application. Further, VE application in the construction industry is initiated mostly in the construction stages while professionals’ preference is laid on the initial project phases. Consequently, the contractor change proposal was identified as the sound approach to deliver VE since motivations emerge during physical construction. Finally, a tailored VE approach was developed considering concept design, developed design, and construction stages with related VE motivations to enhance the VE application in the Sri Lankan building construction context in a simplified manner.
item: Conference-Abstract
Operational energy saving in buildings : a comparison of green vs conventional wall
(2021-07) Madushika, UGD; Ramachandra, T; Zainudeen, N
The green wall concept has been introduced as one of the solutions to reduce energy demand for ventilation requirements while improving the natural vegetation in dense urban areas. Past studies revealed that the energy-saving of green walls can vary substantially, from 35% to 90% across countries such as United Kingdom (UK), Canada, Russia, Greece, China, Saudi Arabia, India, and Brazil. Given these differences in energy saving of green walls due to climatic conditions and other reasons, direct application of such findings to the Sri Lankan context is questionable. Therefore, this study aimed to assess the thermal performance of green wall applications in Sri Lanka through a case study analysis of an indirect green façade with a comparative conventional wall. The required data were extracted through on-site temperature measurements from different points of both the exterior and interior wall surfaces of each building in different time intervals per day for a period of fourteen days spanning from October to November. The analysis shows that the green walls contribute to 21% - 36% of temperature difference compared to the conventional wall. Eventually, this results in 0.06 kWh of energy-saving per m2 of wall area, and thereby green walls contribute to the 80% energy saving for ventilation requirements. Hence, the study recommends that the use of green walls can be considered as one of the energy efficiency solutions while improving natural vegetation in tropical climatic cities and absorbing other benefits of green walls.
item: Article-Full-text
Significant Factors Affecting The Life Cycle Cost Elements Of A Building
(2021-12) Samaranayake, J; Ramachandra, T; Madushika, UGD
Life Cycle Cost (LCC) is a vital decision-making tool for realization of investments. However, it is often challenging to forecast the LCC of a building as it comprises of several elements which are influenced by a range of factors. Hence, this study was carried out to identify the significant factors affecting LCC elements of buildings. Twentyfour (24) factors and ten [10] significant LCC elements identified through a comprehensive literature review were presented to thirty-four [34) experts reached through a purposive sampling method. A questionnaire survey was conducted to collect their views on the significance of those factors while a weighted mean was used to determine the relative significance and thereby identify the level of influence of each factor on the respective LCC elements of buildings. The study concluded that the [6) six most significant factors include: plan shape of the building, size of the building, number of occupants, quality of materials and equipment used, the function of the building, and technology used. Further delving into analysis indicates that all 24 factors influence the construction and maintenance management cost elements at different significant levels. Further, the highest number of elements [8 out of 10), such as construction, utility, administration, services management, cleaning, external work, repair and replacement, and maintenance management are highly influenced by the function of the building. Next to the function, lifetime of the building highly influences the six LCC elements such as construction, utility, administration, services management, repair and replacement, and maintenance management Similarly, every LCC element is influenced by each factor in different levels and further discussed in this study. Hence, the study recommends that cost practitioners should give due consideration to highly influencing factors to optimise the LCC of a building during its early life cycle phase.
item: Conference-Full-text
Study of green roof application in Sri Lanka
(Ceylon Institute of Builders - Sri Lanka, 2023-07-21) Kodituwakku, D; Ramachandra, T; Madushika, UGD
Green roofs are one of the green practices, having widespread use in the European and Asian regions due to their numerous benefits. However, country like Sri Lanka is yet to experience its optimum potential application. Thus, this study investigates the application of green roofs in Sri Lanka in terms of current status of its application, role in the green rating systems and implementation barriers to enhance its application in Sri Lanka. Initially, a preliminary survey, followed by semi-structured interviews with green roof construction professionals was conducted where the collected data were analysed using descriptive data analysis techniques. Amongst the identified set of applications, residential and commercial buildings are the most common building types with the extensive and semi-intensive green roof types. Although the most commonly used rating systems of GREENSL® and LEED have various provisions, a very few out of number of buildings surveyed have incorporated green roofs. According to the green roof construction professionals, the application is limited in the Sri Lankan buildings due to fourteen (14) key barriers. Amongst those barriers, higher initial and maintenance costs, poor awareness of the public on the concept and lack of clients’ willingness on the concept are the mostly identified barriers by the interviewees. Hence, the study recommends taking necessary actions to mitigate the barriers in order to enhance the green roof applications on the Sri Lankan buildings to optimise the multiple benefits if offers.
item: Conference-Abstract
Waste heat generation and potential recovery systems used in Sri Lankan hotels
(2021-07) Lakshan, N; Ramachandra, T; Madushika, UGD
The waste heat recovery concept can be used as a solution to optimise energy consumption while reducing the waste heat in energy generation systems. However, its application in Sri Lankan hotels is still in the infancy stage even though the hotel sector accounts for high energy consumption. Therefore, this research aimed to assess the amount of waste heat generated from the different sources in hotel buildings and thereby identify the most appropriate waste heat recovery systems to the hotel buildings in Sri Lanka through a comparative case study analysis of three similar natured hotel buildings. The required data to perform waste heat calculation were extracted through document reviews and site visits. This study identified the three main waste heat generating sources in hotel buildings: HVAC condenser out, boiler exhaust, and kitchen exhaust. The analysis shows that the condenser out of the HVAC system is the highest waste heat generating source which accounts for an average of 41,823GJ per year while boiler exhaust and kitchen exhaust generate the waste heat of an average of 11,000GJ and 8GJ per year. It is further found that the quality of waste heat generated from the boiler exhaust is higher than the condenser out of the HVAC system and kitchen exhaust. Hence, this study concludes that the boiler has the highest potential of using the waste heat recovery system than the condenser out of the HVAC.