Yep your right they are usually 59.5 or 60 in width standard. It's the space that's eh problem, it actually isn't quite straight so gets slightly narrower as it goes in? It's really infuriating that the builders did that! We can't find a machine that will fit unless I get a compact machine but then it's only a 3KG drum - which is tiny! And a lower speed spin. So we are going to have to move the drawer section of the units and swap with a narrow cupboard that I have things like vases in as it's tall and thinner.
Royal PITA but the builder person is coming Friday to look, he'll hopefully fix it!!