Prefabricated volumetric modular building construction is an emerging technology in many countries used to develop the construction industry through its value-added benefits. The adoption of these novel technologies in the Sri Lankan construction industry has been relatively slow compared with other developing countries, delaying the development of the construction industry and the attainment of the added benefits of these technologies. Therefore, this study aims to identify the suitability of modular construction for the Sri Lankan construction industry via a survey and case study. A questionnaire survey was developed and distributed to assess and identify the benefits of implementing the concepts and constraints in Sri Lanka. Then, the construction cost of a proposed single-story house delivered through conventional and modular practices was compared. The survey results showed that introducing a modular concept to the industry is suitable and would benefit the Sri Lankan construction industry. Further, survey participants believed that the economic benefits brought in by modular construction are significantly more important than environmental and social benefits when selecting modular construction. The case study on a single-story affordable modular house showed a 32% reduction in total construction costs and a 36% reduction in labour costs compared to conventional house construction. Further, costs for total modular construction and labour were 32% and 36% less than those of conventional construction costs and labour costs. Moreover, a 16% reduction in embodied energy was observed when compared with conventional construction. Therefore, the modular concept could be used to construct affordable houses and will be cost-effective with the correct choice of material.

The limited knowledge of the behaviour of modular buildings subjected to different loading scenarios and thereby lack of design guidelines hinder the growth of modular construction practices despite its widespread benefits. In order to understand the robustness of modular building systems, a case study was carried out using the numerical analysis method to evaluate the robustness of ten-storey braced frame modular buildings with different modular systems. Two types of modules with different span lengths were used in the assessments. Then, three different column removal scenarios involving (1) removal of a corner column, (2) an edge column, and (3) an interior column were employed to assess the robustness of modular building cases considered. The forces generated in the elements in close proximity to the removed column were verified to assess the robustness of each building case analysed. The results showed that the change in damping ratio from 1% to 5% has no significant influence on the robustness of the modular building cases considered, where the zero-damping leads to collapse. Corner column removal has not considerably affected the robustness of the braced modular building cases studied. The axial capacity ratio of columns is 0.8 in dynamic column removal in the building subjected to corner column removal, while in interior column removal capacity ratio reached up to 1.2, making it the most vulnerable failure scenario. Doubling the span of the modules (from 2.5 m to 5 m) has influenced the robustness of the buildings by increasing the axial forces of columns up to 30% in the interior column removal scenario. Thus, this study highlights that proper guidelines should be made available to assess the robustness of modular building systems to effectively design against progressive collapse.