In Kuala Lumpur, there are a few heritage schools that are more than 100 years old which have experienced significant infill developments since colonial era. This study evaluates the infill building structures and proposes a suitable design approach of infill development in heritage school. It focuses on the infill development theory, reviews on the physical aspect of heritage school buildings as well as related local policies and guidelines. In order to achieve the research purpose and objectives, the study uses the qualitative methodology. The studyfound that there are 2 infill design approaches, which is the complementary design approach and contrast design approach and both can be used as long as compatible and in harmony with the existing heritage building and site. Through site observation survey, it was found that although infill development at St John’s Institutions and Maxwell Secondary Schools adopted the contrast approach, the outcome were different. Infill development at St John’s Institutions was compatible and in harmony, while at Maxwell Secondary School was theopposite. Therefore, this study suggests improvement on the existing infill structures in the heritage school, either through image restoration or transfer of facilities to future development. Other recommendation include the government providing infill development guidelines for heritage site, encouraging private sector to participate in heritage school conservation and development, and controlling the height of new development within 100 meter radius from heritage buildings.

The urban historic district is one of the man-made places with strong genius loci through its cultural heritage character and values. Architectural heritages are the core element constituting its urban fabric character. However, the emergence of infill buildings that intervene in the urban historic fabric with their conspicuous contrast faç ade architectural design threatens the genius loci of the urban historic districts. Therefore, this paper aims to systematically review the contextual architectural design criteria of infill building faç ade in urban historic districts. Using the content analysis method, this paper extracts the previous scholars' studies on heritage conservation guidelines, contextual infill building faç ade design approaches and the design criteria for the contextual infill building faç ade design in urban historic districts to answer the highlighted issues. In an urban historic district, the contemporary architectural intervention, especially the infill building faç ade design, must critically consider and respond to the existing urban fabric that has long been characterized by the place's genius loci to sustain its cultural heritage character and values. The infill building faç ade design must appropriately be articulated by balancing "compatibility" and "differentiation" elements in its architectural design as well as consider creating a "bond" and having family resemblance with the existing urban fabric of the historic district.