Building airtightness is an important parameter to improve the energy efficiency of buildings. By means of a literature study, as well as the use of empirical data on the specific leakage of more than 300 dwellings, this paper provides insights in the relationships between building airtightness and eight individual variables. A total leakage construct was one of the adopted variables to distinguish cases. Correlational analyses, as well as ANOVA tests show that year of construction, total leakage, roof type, construction method and construction typology have significant relationships with building airtightness, but regression analysis suggests that only the year of construction and the total leakage influence the airtightness. Two-way ANOVA tests show that both have a significant interaction on building airtightness, in terms of specific leakage rate. Considering that the year of construction is related to multiple other variables influencing the airtightness of a building and the number of individual leakages and their sizes can only be assessed after completion, both variables cannot yet help us to estimate the specific air leakage of an object in advance

Nowadays, sustainability has become an important issue in any development project, including area development. Thishappen because the area development requires space, in this case land. As people developing land, it damages theenvironment. It means there will be less balance between built environment and natural environment. This calls forconcern in urban sustainability. One of the ways to restore the balance is to reduce as much land as possible to be builtby maximizing the space. This paper will explore the multiple space use in terms of mixed-use development in differentlevel and also assess mixed land use implementation, which include the concept of diversity in urban sustainability

The purpose of this study was to investigate the natural ventilation potential in an apartment unit in a high-rise building. A corner unit of a two-bedroom apartment was selected for this study, where single-sided and cross ventilation occurred in the unit. This study employed a CFD simulation to model the indoor airflow of an apartment unit in West Jakarta. The units were modelled and simulated using CFD with a RANS k-ε turbulence model. The results were validated with the readings from the field measurements that had been conducted. Based on CFD results, the window position influences indoor airflow. In the case of cross ventilation, a windward opening is more beneficial, while in single-sided ventilation, a leeward opening creates more indoor airflow. Therefore, it is recommended that the characteristic of window design be considered in the early design stage not only to improve indoor air quality but also to maintain privacy and safety measures.

During the last decade, greenery aspect in the building envelope starts to increase their presence in the building design. Vertical greenery system became the one of alternatives that potential to energy-saving in the building. However, in tropical area, researches related to vertical greenery system are enigmatic since reducing heat in tropical area are crutial for maintaining space in comfort condition. In this study, a comparative thermal analysis between green facade and green wall will present. A model called house miniature set up with climbing plans as model of green facade. While for green wall, data measurement was conducted in the office building with green wall as building envelope. The results showed a high potential for energy savings during peak time in the afternoon for green wall (1.5%) and green facade (1.3%) in comparison to the bare wall. While for interior facade are 2.6% for green wall and 2.2% for green facade. Effect of vertical greenery also found in the outdoor air temperature around greenery system. Results show at the hottest time of the day, the green wall and green facade reduced outdoor temperatures by 3.0°C and 1.2°C, respectively. Based on the analysis, compared to green facade, the cooling effect produced by green wall is faster. Possibility, the substrate properties in the green wall also help to decrease temperature. The reduction can be due to the foliage density as the leaves of green wall is denser than leaves in green facade.

Heritage buildings are one of the main concerns in urban development planning and they consequently affect the building code as well. Such concerns were found in many redevelopment projects in a sizeable number of countries aside from Europe and Asia. Strategies, decisions, ways and dilemmas were approached and other points were used as lessons for other projects with similar or even quite different contexts and sizes worldwide. Although Semarang has a specific regulation that protects its heritage buildings, the awareness of the local government and people is still not adequate. This research showed that strategic planning was that was implemented in heritage buildings in some other countries made the buildings become more useful and conserve their authentic value. By studying different cases from different countries, this paper also presented the strategies in regards to heritage building. Suggested also in this paper, that stakeholder’s involvement is crucial in decision-making process.

Historical environment must be conserved due to their contribution toward cultural, social, economic and aesthetic values. They transfer the emotion, thought and backgrounds of social live to modern societies. As one of oldest settlements, Semarang Chinatown gives great influence toward Semarang City and has endless historical values. Old Chinese settlement is very thick with Chinese culture. It becomes the primary source of physical characteristics in this historical environment. However, physical and visual problems come along with the rapid economic growth in Semarang Chinatown. The old buildings that still remains in Semarang Chinatown are in deficient condition and losing their shapes. Moreover, modernization and economic growth influence the change building facade. Several old buildings were replaced with new buildings that tend not to adopt Chinese Architecture style. Consequently, it changes the value of the buildings and the value of the historical environment.