Muppentry.

Definition: woodworking project completed ineptly by person or persons of limited ability or intelligence. Or both. Derived from combination of "muppet" and "carpentry".

Examples (both from the same road, spotted on the same day!):

1. When your kitchen faces the main road, it's not always a good idea to have your kitchen sink facing out the window, especially when some muppet puts the worktop about 10" higher than the windowsill. From the outside it creates a very odd impression, as the window is divided in two - the view into the room, and the view of the plumbing beneath the kitchen sink... Or if you have to do all this, at least get some curtains to hide your embarrassment!
2. When you buy a new garage door, make sure you have an idea of how to fit it, or you know someone else who does. If you can't work out how to do the "up and over" thing, it's probably not normal practice to stick regular hinges on each side, and then cut it down the middle with a chain saw!

Feel free to post your own examples - keep us all smiling!