Javanese traditional house layout in Kotagede Yogyakarta Indonesia: between change and continuity

Change and continuity in traditional architecture have always been interesting topics for discussion and study, because in a dynamic environment both affect each other and continue to occur. Traditional house architecture contains design concepts that have been passed down from generation to generation and become a heritage. Many changes and continuity have occurred, especially in the spatial layout of the house that need to know for conservation purposes. This study was conducted in the old settlement of Kotagede, a heritage district in the southeast of Yogyakarta, Indonesia. The aim of the research is to identify and document changes and continuity of the spatial layout of Javanese traditional houses of Kotagede district that influence its sustainability. Eight traditional houses that represent Javanese traditional houses in Kotagede were selected as case studies. Interviews with the owners and do drawing of the house plans in the early and current periods were carried out to find out the scheme of changes and do not change from the spatial layout. Qualitative and quantitative analysis were carried out by describing and discussing the schemes of changes, including function, zoning, hierarchy, and space access in the early and current periods; and Radar Chart is applied to find more measurable variations and levels of spatial changes. This study found three level of spatial layout changes (low, medium, and high levels) with variety of changes, including the loss of space, the addition of new spaces, and modifications of existing spaces. The form of change has affected the change in other elements, which are access or circulation of space, space hierarchy, and symbolic values of space. Changes in space layout occur due to the need for new functions in space, land limitations, lifestyle changes, and earthquake disasters. Continuity still exists in the basic concept of linear forms of spatial layout, even though the symbolic value of space no longer exists. There is also continuity in the use of house spaces that is adaptive to current needs, and the character of traditional Javanese architecture is maintained. Good management and public awareness of the importance of architectural conservation of traditional residential buildings are necessary to maintain a balance between change and continuity.