The interest in prefabricated building modules is constantly growing due to the increasing possibilities of analysing extensive data sets in computers and the popularity of BIM technology. The ability to manage the position, size and properties of many different elements make it easy to create and evaluate complete modular models at the design stage. Benefits of prefabrication include, among the others, decreased cost, minimisation of environmental impact, and reduced labour on-site. However, making structures and buildings suitable for prefabrication puts additional responsibility on the designer, who needs to choose the modular system, partition the structure and prepare detailed schedules. The article refers to digital control over modular design in the context of the increasing complexity of structures. It focuses on methods and tools that either reduce the designer’s labour or provide him with information that can be used to optimise the structure in terms of efficiency or cost. The article organises the existing trends and presents three experiments on algorithmic control of modular structures to outline the differences in computational methods suitable for particular technologies: masonry, steel, glass and timber construction. The research illustrated in the article was undertaken in response to the need to develop construction technologies in line with the sustainable development trend.