When you’re picking a condo unit for the first time, you may run into floor plans described as being “dual-key”. You’ll also notice they tend to cost more than other equivalent-sized units, but are advertised with benefits like “avoiding extra stamp duties” (a sales pitch that has resulted in no end of confused first-time buyers). Now there are some real, solid advantages of picking dual-key units; but don’t assume they’re better just because they’re more expensive. The benefits of a dual-key unit are situational: What’s a dual-key configuration?

We’ve covered this to some extent in the previous part of this guide, on understanding floor plans. But to quickly recap: a dual-key unit typically refers to a unit with two separated sections: a larger main unit, and a smaller subunit. There’s usually one shared foyer, with a different door for each unit. In some cases, a dual-key unit can also consist of a double-storey unit...