Not sure about your climate Leigh, but here in the US, states in the north, mostly all have cellars, due to the winter frosts. Sometimes the ground will freeze up to 4' deep, which isn't good for a concrete slab. If a foundation requires more than 6-8' deep, (or more) and you have an excavator digging it, you might as well dig out the insides, to give more space under the house. (As you mentioned, for utilities such as a furnace, and other benefits). I can't imagine living in a house W/O a cellar, but I've been in the north most my life. My woodshop occupies most of my little cellar here.