Finally built myself a nice 3D printer enclosure from IKEA cabinets.
Basic idea is to take a shallow (20cm) and a deep (40cm) cabinet frames and to stagger the bottom/top panels and wall panels, making a nice single-piece 60cm cube. A bit more info with a short how-to and a few ideas and nuances.
That would have been even easier, but looks like those cabinets are not sold in US or Canada. (Search turns up hardware and/or other storage cabinets)