In a single day, an additional storey is added to an existing townhouse in Ghent. The existing roof is removed and replaced by a CLT slab, on top of which a small room made of the same material is constructed, providing access to the new roof. The solid timber panels, composed of laminated wooden elements, are meticulously prepared and delivered fully prefabricated to the site. Thanks to the relatively low weight of timber, the intervention is fairly straightforward and has only a limited impact on the existing structure.