Here are some articles by Nuki, which were published in the international scientific journal Science Direct. If you wish to receive a copy of the full text article, you may contact us or go to the links as indicated at the bottom of each article.

Indonesian residential high rise buildings: a life cycle energy assessment

Authors: Nuki Agya Utama and Shabbir H Gheewala

The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok, Thailand

Available online on 30 July 2009 at Elsevier Science Direct's Energy and Buildings: an international journal devoted to investigations of energy use and efficiency in buildings

Abstract

This study evaluates the effect of building envelopes on the life cycle energy consumption of high rise residential buildings in Jakarta, Indonesia. For high-rise residential buildings, the enclosures contribute 10-50% of the total building cost, 14-17% of the total material mass and 20-30% of the total heat gain.

The direct as well as indirect influence of the envelope materials plays an important role in the life cycle energy consumption of buildings. The initial embodied energy of typical double wall and single wall envelopes for high residential buildings is 79.5 GJ and 76.3 GJ respectively.

Over an assumed life span of 40 years, double walls have better energy performance than single walls, 283 GJ versus 480 GJ respectively. Material selection, which depends not only on embodied energy but also thermal properties, should, therefore, play a crucial role during the design of buildings.

Keywords: Building envelopes; High rise; Tropical climate; Embodied energy; Life cycle energy

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Life cycle energy of single landed houses in Indonesia

Authors: Nuki Agya Utama and Shabbir H. Gheewala

The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok, Thailand

Available online 9 May 2008.

Abstract

Building enclosures contribute 10–50% of the total building cost and 14–17% of the total material mass. The direct as well as indirect influence of the enclosure materials plays an important role in the building life cycle energy. Single landed houses, the typical houses in Indonesia, have been chosen for this study. The life cycle energy of the house enclosures and energy consumed during their life spans shows intriguing results.

The initial embodied energy of typical brick and clay roof enclosures is 45 GJ compared to the other typical walls and roof material (cement based) which is 46 GJ. However, over the 40 years life span of the houses, the clay based ones have a better energy performance than the cement based ones, 692 GJ versus 733 GJ, respectively. The material selection during the design phase is thus crucial since the buildings have at least 40–50 years’ life span.

Keywords: Building envelope; Embodied energy; Houses; Indonesia; Life cycle energy

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Influence of material selection on energy demand in residential houses

Authors: Nuki Agya Utama and Shabbir H. Gheewala
The Joint Graduate School of Energy and Environment, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand

Available online 12 September 2008.

Abstract

Utilizing local materials for improving the energy demand in the single landed houses in Indonesia is very promising, since it also entails less cost during production and transportation. Many possible scenarios have been proposed towards this end such as improving building craftsmanship, using double walls with cavity, double walls with bamboo in between and introducing less transparent glass.

The scenarios are tested in terms of the additional initial investment in terms of energy and cost and the benefits accrued for life cycle energy and cost. Energy and cost payback are computed to evaluate each scenario and a framework proposed for quick screening of building materials.

Keywords: Building fabrics; Environmental performance; Material properties

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Self-sufficiency in the provision of Indonesian construction materials

Authors: Nuki Agya Utama; Robert Kodoatie
p. 956-963
10th DBMC International Conference on durability of building materials and components, 2005

Abstract

In line with the plan of the Indonesian government to build and develop the infrastructure as well as building a million houses for middle low incomers, the provision of local construction material is strictly prerequisite. The purpose of building up the infrastructure (i.e. roads, dams, power plants, drainages and ports) in addition to mass houses is providing the job opportunity and increasing the public services demand.

The use of sustainable construction materials in Indonesian construction business is still considerably low, whereas the use of local material is rare. Business purposes with economical benefit considerations remain to be the major issue in the local construction firm. Java as the most developed region in Indonesia customarily supplying woods for construction purposes from the tropical rainforests of Borneo and Sumatra, even though the use of these material are more durable but in the other hand its energy consuming and lack environment awareness.

Furthermore its construction sand materials had been largely taken from the beach area, which brings about a number of serious environmental degradation. Likewise the construction material for Borneo, Sumatra and Eastern Indonesia most of the advanced production for material supplies such as cement, pre-fabricate concrete, steel and finishing material are mostly coming from Java region. This article aims to generate the knowledge vis-a-vis the possibility of self sufficiency and sustaining its construction material durability within local construction firm throughout the country.

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