South Florida apartment rental rates grew 10 percent to 15 percent in the last two years and are likely to keep trending upward in 2014. But industry watchers say that’s not necessarily good news for building owners.

Broward rates grew 2 percent to 3 percent in the last quarter, according to data from Franklin Street Real Estate Services. And in the fastest-growing infill locations, such as downtown Miami, average rents reached $2.25 per square foot—up 29 percent from about $1.75 two years ago.