Enhancing off-site manufacturing through early contractor involvement (ECI) in New Zealand

Procurement strategies that enable early contractor involvement (ECI) in design may enhance off-site manufacturing (OSM) by overcoming previously identified barriers to its uptake. Involving constructors during the design stage can reduce the risk of design buildability issues, and standardising traditionally bespoke ECI processes may help overcome cultural resistance to unfamiliar OSM technology. Following literature review and using case studies, document analysis and legal doctrine, a two-stage ECI conceptual process model for New Zealand is proposed. This was tested and refined following feedback at a conference. The model comprises a first-stage pre-construction contract and a second-stage standard-form construction contract. Key process variables are considered with solutions to provide collaboration and transparency while maintaining competitive fixed pricing across the supply chain. Legal doctrine analysis is used to distinguish between design buildability obligations and design codes compliance. The model contributes towards the development of a standard form for pre-construction contracts.