A model for implementing product modularity in buildings design Cecilia Gravina da Rocha Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil, and Hana B.C. El Ghoz and Sidnei Jr Guadanhim Universidade Estadual de Londrina, Londrina, Brazil Abstract Purpose – The purpose of this paper is to examine the fundamental underpinnings of product modularity and how these can be adapted to construction and its specificities (e.g. one-off products delivered by temporary supply chains) to create a model to design modular buildings. Design/methodology/approach – This research adopts a design science research approach. Explanation I (substantive theory devising based on the analysis of an artefact ‒ a low-income housing project) is used, followed by Solution Incubation (a model to implement product modularity in buildings design). Findings – The model allows product modularity to be implemented at distinct levels (i.e. building, systems and components) at a single stage (building design), different from manufacturing where each level is considered at a distinct stage. This is in line with the project investigated: modularity was considered for house layouts, roof types and gable formats. Practical implications – The model provides a hands-on tool for practitioners to design modular buildings. The low-income project is also extensively detailed: three-dimensional models, floor plans and conceptual diagrams (outlining how fundamental underpinnings were applied at each level) are presented. There is a lack of comprehensive accounts such as the one presented here to demonstrate the application of product modularity in real-world projects. Originality/value – This paper identifies and adapts the fundamental underpinnings of product modularity to construction, and it details how these were applied to a low-income housing design at distinct levels. Based on these two endeavours, a model to implement product modularity in buildings design is proposed. Keywords Design, Design management, Platform Paper type Research paper 1. Introduction Modularity, which refers to the partitioning of a system into smaller parts, has been examined in manufacturing for several decades. When applied to products, modularity refers to the partitioning of the product into chunks and the definition of interfaces among these chunks (e.g. Ulrich, 1995; Baldwin and Clark, 1997). Indeed, product modularity and related notions, such as off-site construction (OSC) and pre-fabrication, have been recently examined. Boyd et al. (2013) identified industry drivers and constraints for OSC in Australia, whereas Tam et al. (2015) evaluated best practices of pre-fabrication implementation in Hong Kong. Li et al. (2014) examined the waste reduction in China yielded by pre-fabrication. However, some studies focused on operational implications of OSC (i.e. time and cost) by adopting multi-skilled labor (Arashpour et al., 2018) or autonomous production tracking system (Arashpour et al., 2015). Finally, a review on the integration of OSC and BIM and a bibliometric study on OSC (Hosseini et al., 2018) have been carried out. Product modularity has also been used to increase value by providing customized houses or units (in apartments) that meet dwellers requirements (e.g. Hofman et al., 2006; Barlow, 1999; Barlow and Ozaki, 2003; Frutos and Borenstein, 2003). It has also been applied to simplify the production flow in customized apartments building projects (e.g. da Rocha et al., 2016; da Rocha and Kemmer, 2013). In spite of these studies and the recent investigations of OSC and pre-fabrication, what constitutes a module in the construction sector remains unclear (Gosling et al., 2016; da Rocha and Kemmer, 2018). Gosling et al. (2016) examined what was a module in fifteen construction projects and Engineering, Construction and Architectural Management Vol. 27 No. 3, 2020 pp. 680-699 © Emerald Publishing Limited 0969-9988 DOI 10.1108/ECAM-02-2019-0096 Received 27 February 2019 Revised 10 July 2019 26 August 2019 Accepted 29 August 2019 The current issue and full text archive of this journal is available on Emerald Insight at: www.emeraldinsight.com/0969-9988.htm 680 ECAM 27,3