Browsing by Author "Ramachandra T"

Now showing 1 - 6 of 6
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    Application of green retrofit technology: A systematic review
    (1/01/2020) Weerasinghe A; Ramachandra T; Rotimi JOB
    Green retrofitting is a valuable approach for upgrading existing buildings towards sustainable performances. However, the lack of knowledge about the true cost effects and potential savings of green retrofits distracts building proprietors from paying those retrofits. Therefore, the current study reviewed fourteen studies available in the extant literature and identified twenty-eight different green retrofits incorporated into various buildings with their cost effects and saving potentials through a subsequent desktop study. The results indicated that the majority of green retrofits offer savings related to energy consumption, CO2 emissions, cooling load, and operating costs. Moreover, energy-saving lighting modifications are widely done in most buildings, while solar collectors, photovoltaics, and low-emission double glazing are used less often due to the long payback period and increased cost of implementation. Alternatively, the use of retrofits with lower costs and high savings, like BMS, lighting controllers, and boiler efficiency improvements, offsets the above setbacks. Furthermore, the highlighted retrofits include green roofing, bicycle parks, CO2 sensors, and air tightening retrofits, which also save energy. Rainwater harvesting absorbs carbon dioxide and runoff water, where implementing subsystem-level water meters, appliances with low flow rates, and greywater recycling save and recycle the portable water. Accordingly, the study promotes the effective implementation of green retrofits in future buildings.
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    Causes of payment problems in the New Zealand construction industry
    (University of Technology Sydney (UTS) ePress, 2015) Ramachandra T; Rotimi JOB
    Payment delays and losses persist in the construction industry and continue to be a key concern to industry practitioners. Therefore an exploration of the key causes of payment delays and losses is undertaken in this study with the ultimate objective of seeking mitigating solutions. The study adopted a survey approach using an online questionnaire, administered to practitioners from the New Zealand construction industry, comprising consultants, head contractors and subcontractors. The data obtained was analysed using inferential statistical techniques, including comparing means and factor analysis. Factor analysis enabled clustering of the inter-related causes of payment delays and losses in order to find reduced number of causes. Accordingly, the study found that payment problems mainly relate to contractual issues, financial strength of industry players, disputes, short-comings of payment processes and ‘domino effects’. Among them, the financial strength of critical industry players was considered central to payment problems. The study concludes that any solution to these problems must address these primary causes, as a rational starting point. Thus procuring a feasible form of financial security at the outset of a project, and the pre-qualification of the financial status of critical project participants, were found to be significant in the mitigation of construction payment risks
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    Comparative Life-Cycle Cost (LCC) study of Green and Traditional Industrial Buildings in Sri Lanka
    (Elsevier, 2021) Weerasinghe AS; Ramachandra T; Rotimi JOB
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    Effects of green retrofits: A case of industrial manufacturing buildings in Sri Lanka
    (1/01/2019) Weerasinghe AS; Ramachandra T; Nawarathna A
    The impact of built environment on the global warming, greenhouse gas emissions and natural resources depletion is staggering. Consequently, existing built environment will have very high responsibility in dealing with global issues, unless the rate of green retrofitting is amplified. Existing buildings are accountable for 39% of energy use and 35% carbon dioxide emissions, whereas, green retrofitting can achieve 40%-60% energy saving, which contributes 20%-30% carbon emission reduction. Nevertheless, the building owners are less willing to pay for retrofits due to high initial cost and identifying the most cost-effective retrofits for a particular project is still a major challenge. The current study therefore analyses the costs and saving implications of various green retrofits incorporated into an industrial manufacturing building in Sri Lanka. The study used mixed methods in data collection where professionals involved in green retrofits industrial manufacturing buildings were interviewed to identify the green retrofit technologies implemented and the reasons for selection of those green retrofits and subsequently a detailed costs and saving potential analysis of green retrofits incorporated in the selected green retrofit certified industrial manufacturing building was performed using Net Present Value and Simple Payback Period. The analyses show that the use of retrofits related to energy, indoor environmental quality and water are at a significant level in industrial manufacturing buildings in Sri Lanka. Moreover, the implemented retrofit projects indicate the financial viability of green retrofits with positive net present values and simple payback period of less than 5 years. Considering the lifetime financial returns of those retrofits, each indicates significant benefits compared to initial investment. Therefore, the success of these actual retrofit scenarios would enable to identify the most appropriate retrofits based on the potential expenses and returns involved, and thereby assist building investors to incorporate most feasible retrofits into their existing buildings.
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    Implications of sustainable features on life-cycle costs of green buildings
    (1/09/2020) Weerasinghe AS; Ramachandra T
    The green buildings seem unattractive to developers who prioritize fast investment returns, due to costs attributed to implementing sustainable features and consequently, only 19% of existing buildings are certified for green, globally. Furthermore, green buildings are aimed at achieving a minimum sustainability level in certification. Therefore, the current study aims to investigate the significant sustainable features and the implications of those features on green buildings' life-cycle costs. The study involved a preliminary investigation to find the significant sustainable features implemented. Subsequently, two green buildings were carefully selected, and a detailed analysis was performed. The data relating to the green building construction, operation and maintenance costs were collected and analysed using Net Present Value. The features have varying degree of contribution to sustainability in terms of the achievement of allocated points in the rating system. The certified buildings have achieved over 75% of allocated points in terms of water efficiency and sustainable sites features, while the achievement level of other features is below average level. Further, highly achieved features are more economical in terms of their less contribution to construction and maintenance costs. On the other hand, the features with lower achievement in certification, contribute significantly to construction and maintenance costs, while providing higher savings during operation. Therefore, the current study recommends, green building investors to select the most suitable features for a given construction based on their respective contributions to the life-cycle cost of green buildings.
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    Towards sustainable commercial buildings: An analysis of operation and maintenace (O&M) costs in Sri Lanka
    (Emerald Publishing Limited, 14/09/2020) Weerasinghe AS; Ramachandra T; Rotimi JOB
    Purpose Rising energy costs and increasing environmental concerns are catalysts for introducing sustainable design features in buildings. Incorporating sustainable design features in commercial buildings cannot be overstated because it could confer benefits to the investor (owners) and occupants. This study aims to develop a model that could aid in the prediction of operation and maintenance (O&M) costs from the knowledge of building-design variables. There is little evidence that design variables influence the O&M costs of buildings. Therefore, this study investigates the relationship between design variables and O&M costs in commercial buildings with the intent of developing a cost model for estimating O&M costs at the early design phase. Design/methodology/approach The study was approached quantitatively using a survey strategy. Data for the study were obtained from 30 randomly selected commercial buildings in the CBD in Colombo, Sri Lanka. Pareto's 80/20 rule, correlation and regression analysis were performed on the data to prove the statistical relationships between the buildings' O&M costs and their design variables. Findings The study found that 12 significant O&M costs elements contribute to about 82% of total O&M costs. Repairs and decoration had a strong correlation with building shape. Furthermore, the regression analysis found that O&M costs values were primarily dependent on the building size (the gross floor area and height of the buildings). The gross floor area and height handled over 73% of the variance in the O&M costs of commercial buildings in Sri Lanka. Originality/value These findings are a useful insight into the principles for design economies that could contribute to more sustainable commercial buildings.