Offsite construction techniques continue to receive considerable attention in academic/research discourse. Whilst discourse in seminal literature critique the positive and negative aspects of offsite; on balance, the benefits outweigh the barriers, especially when fully integrated and managed. From a project management perspective, the techniques applied to construction projects typically commence in determining the project’s work breakdown structure (WBS). Whilst the WBS is applicable to offsite deliverables, reflecting site-based construction activities and concomitant dependencies with the manufacturing processes, there are slight discrepancies in processes, and equally, some areas of repetition and duplication. This mismatch has a fundamental impact on integration, creating pockets of confusion, where less seamless (sub-optimal) synergy between offsite and onsite works is lost. This is an acknowledged challenge. There is, therefore, a real need to retain the product breakdown structure, whilst ensuring a seamless interface with the onsite works is maintained. This is a challenge. Whilst the WBS-matrix has been implemented in the project management domain to bridge the ‘products’ and ‘activities’, this arrangement has not yet been developed for offsite building construction projects. This paper reports an on-going research project set up to implement WBS-matrix for offsite construction projects. Two cases of recently completed offsite construction building projects were studied to analyse current practices – to inform the way forward to further develop the WBS-matrix. Findings from this research provide clear guidance for practitioners involved in offsite construction projects; particularly on the development of the WBS-matrix for manufacturing deliverables/activities in order to more effectively manage offsite construction projects.