The Netherlands is facing a severe housing shortage. Newly build constructions are generally viewed as the go-to solution. Alternatively people can make more intensive use of existing constructions. Floor addition is viewed as a promising endeavor to increase the utilization of existing constructions. With their light weight characteristics biobased materials lend themselves very well for this purpose. This paper explores the economics of factory produced biobased floor addition. A literature study has been executed, as well as a Co-Creation sessions held with a construction team consisting of a project developer, a social housing agency and this paper’s author as an action researcher. In the session it has been explored how an integral approach could lead to cost reductions. During the sessions a budget review was held including various scenarios where the floor addition housing unit was approached as a biobased product instead of a traditional project. For many production processes a learning rate is observed, meaning that costs are reduced at a constant rate for each doubling of production. The general construction sector is not experiencing such a learning rate, however modular production in factories does seem to exhibit a building cost reduction potential of between 15% and 20%. While at the moment (2025) factory produced biobased floor additions seem to be more expensive than traditional building, they theoretically show the potential to bring overall construction costs down with anywhere between 15% and 39%. Amongst other reductions, product thinking can reduce financing costs and lower inflation adjustments, leading to this increased saving potential. More research, as well as actual projects are needed to verify the preliminary findings of this paper.