Need a garage or land to build one

[Escort2dr]

Currently live in a detached house with integral garage and bugger all space to build another garage; I had some stupid idea that I could either buy a bit of land locally and have a garage built, or buy just a garage on its own.

Question is, are there any specific websites that list this sort of thing (e.g. there are if you want to buy woodland)? Tried the estate agents but nothing forthcoming.