Sivakumar Palaniappan

The life cycle energy of a building consists of construction energy, operational energy and demolition energy. Construction refers to initial construction as well as recurring maintenance and repair work. Initial construction represents manufacturing of construction materials, transportation and site related on-site construction processes. Only a few studies focused on life cycle energy use of Indian residential buildings. However, the energy use due to on-site construction processes is either ignored or not modelled with adequate level of detail at present. This paper presents a case study on life cycle energy analysis of a residential development consisting of 96 identical apartment-type homes located in Southern India. Energy use due to transportation of materials and construction equipment use at site are quantified. Sensitivity analysis is carried out to study the influence of building service life and monthly electricity use per home on the relative significance of construction energy and operational energy. The construction energy is found to be a significant component of life cycle energy of residential buildings with partial or no air-conditioning. Further, reduced building service life period and increased energy efficiency achieved in the operational phase makes the construction energy as important as the operational energy with respect to life cycle. © 2014 Elsevier B.V.

Cement is one of the most widely used materials in construction. This study presents a process-wise evaluation of energy use and CO2 emissions for clinker, Ordinary Portland Cement (OPC) and Portland Pozzolana Cement (PPC) using the principles of life-cycle assessment. Two cement plants located in India are considered as typical case studies. The gate-to-gate system boundary condition is considered. The energy use for clinker is found to be 3990 and 3626 MJ/ton for case studies 1 and 2, respectively. The associated CO2 emissions for clinker are 849 and 868 kg CO2/ton. The energy use for OPC is 4015 and 3821 MJ/ton for case studies 1 and 2, respectively. The related CO2 emissions are 802 and 855 kg CO2/ton. The energy use for PPC is 3077 and 2733 MJ/ton for case studies 1 and 2, respectively. The associated CO2 emissions are 606 and 595 kg CO2/ton. It is observed that the energy use and CO2 emission of PPC are at least 20% less compared to OPC. The results are compared with five geographical regions across the world.

Evaluation of embodied energy and embodied carbon of construction materials and processes will enable construction industry stakeholders to consider sustainability as a design criterion in the planning phase. This would help in choosing appropriate building plan, materials and construction methods and technologies to minimize the life cycle energy.A comprehensive inventory database that is updated at regular intervals is needed to facilitate the above evaluation. The construction sector contributes to about 8% of India’s GDP. Significant growth is expected in the Indian construction industry in the next decade. There is a strong need for economic growth with optimal use of natural resources. Methodologies used for creating the embodied energy database in other countries needs to be simplified before these are applied in India. This study presents a process flowchart that can be used to create a simplified method for embodied energy measurement considering user requirements and resource constraints.

This paper quantifies carbon emissions due to on-site equipment use in the post-tensioned slab foundation construction process of production homes in Phoenix Arizona. The construction activities performed during post-tensioned slab foundation construction, trades/sub-trades/vendors and the list of construction equipment used for every activity are identified. Data collection involved field visits to several subdivisions, interviews with trades, quantification of use time and the fuel use rate for each equipment as well as the fuel type used for every construction activity. Emissions from fuel consumption were quantified using the guidelines provided by the U.S. Environmental Protection Agency. Analysis of emissions indicates that the concreting trade, the plumbing trade and the grading sub-trade are the three most significant trade components. Activities 'set floor', 'plumbing', 'pour floor' and 'backfill and grading' are the four most significant construction activities. Emissions of on-site equipment use are in the range of 4 to 15% of emissions due to transportation. This study is useful for home builders, trade contractors and vendors involved in production home building construction to measure emissions of on-site construction processes, identify significant construction activities and trade components and plan for improvement. © 2012 ASCE.

Significant amount of resources such as materials, energy, water, and land are consumed during the design, construction, operation, maintenance, and end-of-life phases of buildings. There is an increased focus on reducing the environmental footprints associated with buildings. Green building ratings are used as practical tools for implementing sustainability in construction projects. There are several green building rating tools used across the globe. In India, three green building ratings are used, namely the U.S. LEED, IGBC LEED, and Green Rating for Integrated Habitat Assessment (GRIHA). The certification levels vary across green building ratings. For example, the U.S. LEED rating ranks buildings at "Platinum", "Gold", "Silver", and "Certified". Similarly, the GRIHA rating ranks buildings at "5 Star", "4 Star", "3 Star", "2 Star", and "1 Star". This study examines the relationship between certification levels and sustainability indicators of GRIHA certified green buildings in India. Sustainability indicators such as the energy performance index (EPI), energy use reduction, and water use reduction are considered. The analysis is based on the data collected for 45 GRIHA certified green buildings. This study presents some insights on the relation between certification levels and sustainability indicators of green buildings.

Green building rating schemes are used in industry practice as a practical tool for sustainable development. Green building ratings facilitate conservation of natural resources and reduction in environmental impacts while satisfying the user requirements. The credit structure, indicators, level of certification, priorities allocated to environmental, economic and social aspects of sustainable development vary widely among the green building schemes used in different countries. This study presents a comprehensive comparison of credit structure and indicators of ten green building rating schemes that are widely used in North America, Europe and Asia. Green building schemes namely Green Globes, LEED USA, BREEAM, DGNB system, GRIHA, IGBC system, BEAM Plus, Green Mark, CASBEE and Green Star are considered. The comparison is performed at six different levels. The extent to which the sustainable development objectives are met in these schemes is evaluated. Further, this study examines the credit structuring of the two Indian green building schemes – GRIHA and the IGBC system, identifies the areas of improvement and proposes a framework for the next-generation green building scheme that could be adopted in India. The findings of this study are beneficial to improve the effectiveness of green building rating schemes in India.

The Government of India is on a mission to meet the housing needs of all in the society by 2022. This implies that about 27 million houses are expected to be constructed in the next 5 to 10 years. As of today, 5.1 million houses have been sanctioned under the Pradhan Mantri Awas Yojana. Houses for Economically Weaker Section (EWS) group and Low Income Group (LIG) represent a major portion of this initiative. Construction of millions of houses is expected to generate large demand for materials and energy at the national level. There is a need to evaluate alternate materials, construction methods and construction plans to conserve materials and energy use at the aggregate level. This study presents a review of various housing initiatives undertaken in India, housing technologies and evaluation criteria that are used to choose an appropriate technology. Further, a discussion on sustainability aspects of low cost house construction is presented.

The building life cycle consists of production, on-site construction, operation and demolition phases. The energy use due to construction (i.e. materials and on-site construction) represents a significant component of life cycle energy in case of naturally ventilated or partially air-conditioned buildings. Earthmoving is one of the major parts of construction processes and it involves the use of heavy equipment. This study presents the influence of technological, operational and site related parameters on the performance of earthmoving operations using five case studies. The energy use due to ‘excavation’ and ‘excavation and transport of soil’ is in the range of 14–89 MJ/cu.m. and 19–135 MJ/cu.m. respectively. The choice of equipment selection and its influence on the time (duration), cost, energy use and emissions of earthmoving operations are presented using trade-off analysis. It is observed that the cost of transporting soil could be higher than the excavation cost if the truck is not utilized effectively. A procedure for incorporating sustainability metrics into earthmoving operations during the planning phase is presented. The practical application of this work in industry practice is also demonstrated. The findings are expected to be useful for construction planners in decision making including sustainability metrics.

The consumption of cement in India and other emerging economies is expected to increase because of the continuing push towards development of housing and infrastructure. The increasing production of cement and utilization of concrete are bound to have a major impact on sustainability. The present work proposes a framework for sustainability assessment, in terms of the CO 2 emissions and energy demand, that can be adopted in cases where suitable databases are not readily available. Case studies for cement manufacture have been considered in South India, with different system boundaries such as ground-to-gate, gate-to-gate and CSI. The assessment made using data from the plant and other sources highlights the benefits of using supplementary cementitious materials (SCMs) in terms of reducing the impact of cement and concrete. More importantly, limestone calcined clay cement shows considerable promise in terms of reduction in CO 2 emissions and energy demand in both cement and concrete, with more improvement in higher grade concrete.

The use of cooperative cranes can improve the cost effectiveness of heavy lift operations. However, the complexity in developing a reliable lift plan prevents the widespread use of cooperative crane lifts. The availability of a computer-aided planning system can improve planning efficiency and reliability. Path planning is an important subtask of the lift planning process. This paper presents work done to develop a computer aided path planner for two crane lifts. Two heuristic search methods, hill climbing and A*, were implemented for automating the path-planning task. Search space was represented using the concept of configuration space. The effectiveness of the search methods was evaluated by solving three problems with increasing levels of complexity. The formulation of these problems was based on the type of movement of cooperative cranes (in synchronous or asynchronous manner) and the presence of trapping space. It was found that while the hill climbing approach found feasible paths in a few seconds or minutes, these paths were far from optimal in situations containing trapping space. In contrast, the A* search resulted in near optimal paths, but the execution time was of the order of hours. © ASCE.