Purpose: The purpose of this study is to focus on identifying building elements with design defects and established the relationship between design defects and difficulties in carrying out maintenance works.Design/methodology/approach: A total of four cases have been selected covering primary‐ and secondary‐level for both National and National‐type schools (commonly known as vernacular schools). Interviews with school management were carried out throughout the study to assess the common design defects in the buildings.Findings: A list of the design defects that have caused high maintenance cost was tabulated. It could be concluded that the most common design defects are building façade and missing slot underneath the floor slab which led to more defects.Research limitations/implications: Only four schools in Penang, Malaysia were involved in this study. Data were gathered from the school management and maintenance personnel. No data have been obtained from the designers because difficulties in tracing the designers record since the school age are more than 20 years.Practical implications: The study recommended that expert maintenance personnel shall be employed in the design stage to minimize design defects in school projects which in turn minimize the cost of building maintenance.Social Implications: Safety and health of the students could be affected if there is no accurate measures being adopted to overcome the issue.Originality/value: A very limited study has been carried out with regards to design maintenance for school buildings in Malaysia.

This research aims to utilize Coal Furnace Bottom ash (CBA) and Oil-Palm Boiler Clinker (OPBC) as fine aggregate in concrete mix proportions. They are solid wastes from power plant and Oil Palm industry, respectively. Since these by-products do not have any primary use and are pure waste, an opportunity to use them as aggregate in concrete industry not only is economical but also will be an environmental friendly opportunity leading towards a more sustainable production chain. CBA and OPBC sands had similar grading to normal sand but have lower density and higher water absorption. In a high strength concrete, normal sand was replaced up to 25% with either CBA or OPBC. Test results showed that although water absorption of these wastes was more than normal sand but the slump value of concrete containing each of these wastes showed that these concretes had good workability. All mixes containing these wastes had slightly lower compressive strength at early ages and equivalent or higher compressive strength at later ages compared to control mix. The 28-day compressive strength of these concretes was in the range of 69-76 MPa which can be categorized as high strength concrete. In general, the performance of OPBC was better than CBA at 25% replacement level. However, it is recommended that at least 12.5% of total volume of fine aggregate in a high strength concrete is used of CBA or OPBC.

Purpose: – The purpose of this paper is to identify the most influential buildings elements in term of the cost for timber restoration works. Design/methodology/approach: – The research employed the case studies methods with questionnaires surveys. Two case studies were chosen and questionnaire surveys were distributed to contractors and consultation companies. The cost was identified based on the elemental cost analysis of historic timber buildings. Findings: – The restoration of historic timber buildings in Malaysia has grown rapidly, especially in the UNESCO world heritage sites, Melaka and Penang. Data obtained on the restorations of timber buildings show that the most influential elements were upper floors, roofs and walls. Termites’ invasions and the lack of building analysis were found to be the major issue in timber restoration works. In addition, the availability of timber material contributed significantly to the increase of cost for restoration works. Originality/value: – The cost for every element was identified and was used as a reference for new restorations projects of historical, timber buildings. This paper also highlighted the causes for the problems and the factors affecting the cost of timber restoration works. These data are useful information, especially for surveyors and contractors who are involved in the restoration of historic timber buildings. Maintaining or replacing these elements with other material can help to minimise the restoration cost of timber buildings in Malaysia.