This sort of plotline is catnip to many readers. Basically, it takes the protagonists and places them in a situation in which they feel trapped (literally or figuratively.) Because they are caught in close quarters, very close in some cases, the characters are forced to learn about each other very quickly and romance develops. Sometimes they have to work together to get out of their circumstances. Sometimes they’re “stuck” for quite some time and might even have to share sleeping quarters. (Don’t we all love that part?)
Forced proximity romances don’t always take place in quarters as tight as wonky elevators. Many of us have enjoyed stories in which the characters are snowed in somewhere cozy. Being snowed in isn’t such a hardship when you’re stuck with a sexy love interest in a quaint log cabin…one that has a roaring fire. Some of these romances are fun and flirty with low stakes, but others are full of suspense. Imagine you’re on the run, with bad guys hot on your heels. Your car has just broken down in the middle of nowhere, and your only option for help is to approach the mysterious house at the end of a winding road. Luckily for you, the owner of that house is a hottie, a former Marine, and is more than willing to shelter you for a few days.
Do you see where I’m going with this? Close proximity tends to heighten the emotions in a romance. The protagonist is compelled to make split-second decisions about the other person sharing those cramped quarters. Because these romances often take place over a shorter span of time than others, the characters must confront difficult truths earlier in the relationship. Frustration and fear can develop, but so can curiosity and lust. And we all know what happens once lust kicks in!