And further to our bench-building carpentry efforts:
A cold frame.
Not wanting to waste the last scraps of floorboards or an old window found in an alcove full of junk at the last place, we built a cold frame for raising seedlings. While we don't need to keep our seedling safe from frost very often, we do struggle to keep them moist enough in baking heat, and this has helped with that. Currently it has marigold and bok choi seedlings to replace the ones that kept getting savaged by bugs when planted directly, and nasturtiums.
The construction of this was full of confused conversation about why the other person kept holding it upside down until we realised we were visualising very different interpretations of our verbally agreed upon plan. So it has an odd tilt in one part, but it still works a-okay.