These are the 20 most expensive neighborhoods for renters in the US

Over the past decade, more and more people have been renting instead of buying homes. A survey from the Harvard's Joint Center for Housing Studies found that renter households soared by nearly 9 million from 2005 to 2015; and at the end of 2015, almost a third of US households lived in rental housing.

Much of this increase is driven by growth in suburban renters - as downtown areas have become less affordable for lower- and middle-income residents, many of them have been pushed to the suburbs, but still can't afford to buy homes.

And for most renters, their current situation isn't ideal. They would rather own their own home, and not pay incredibly high rents, but may have lost their house to forclosure during the recession or can't qualify for a mortgage.

But for a subset of the population - a mostly affluent subset - preferences are actually shifting towards renting. People want to live within walking distance or a short commute of work or school or nightlife. They don't want the suburbs, and they're willing to pay the high rent for it.

HomeUnion, an online real estate investment management firm, has released a list of the 20 most expensive neighborhoods or cities to live for these so-called "renters-by-choice."

Read on to see where rent is in the highest demand.