Variation orders are a frequent occurrence in the construction phase of Malaysian building projects. Increased construction time and costs are inevitable when variation orders appear. The aim of the current research is to identify the effectiveness of a "cost and time model" in controlling variation orders during the construction of residential projects in Malaysia. The model was derived from a literature review, which also examined how case studies and data have been utilised to identify the causes and effects of variation orders. These were analysed using multiple linear regression analysis. Three independent variables were identified as significant positive causes, while two dependent variables were determined to be the effects of a variation order. The independent variables signify the owner’s changes to the scope of work, construction materials and procedures, as well as their modifications to the specifications. The cost and duration of the project is the dependent variables. The model developed was found to be suitable in practice and the authors propose its application in the early stages of residential construction projects to control the occurrence of variation orders in such projects in Malaysia.