Here [0] is one I took a while ago. One of the reasons for building this toy was to have an Emacs device with a physical keyboard to use while commuting.
I love custom handheld computer projects like this.
Few years ago I wanted to build one as a hobby/toy project with parts that are more or less easily available. So I did [0]. Instead of using a pre-made keyboard I used simple push buttons and instead of specialized keyboard controller I used an Atmega328P. Most of the components are through-hole and easy to solder. Anyway, the couple of the handhelds I built are sitting in a drawer at home, but it was fun building it nevertheless.
Depends where in Europe. I'd say in Northern Europe, especially in Scandinavia wood is more frequently used when building homes.
In other places the roof structure is often made of wood. And although technically it's not part of the building, concrete forms used for foundation/walls are mostly made of OSB/plywood.