From the conference paper : "The authors examined how to improve the total (onsite and offsite) labour productivity of production and assembling of fast retrofitting concepts in the Netherlands. The authors analysed the collected data of two NetZero energy renovations in which the initial process were quite traditional. In the first case the labour productivity can increase spectacularly by prefabricating the roof. In the second case the providers modernized the process by working in multi-disciplinary teams. No evidence have been found that working in a multi-disciplinary team can increase the labour productivity but the time for realization did decrease."