A global property consultant says there are worrying signs that Dubai could be facing another economic bubble.

In its annual report on real estate trends in the United Arab Emirates, Jones Lang LaSalle pointed to a number of concerns, including unsustainable growth in property costs and speculative buying following Dubai's win to host the world fair in 2020.

The group says that the rise in residential property prices last year was "irrational." Property prices in Dubai jumped by more than 22 percent last year and rents by 17 percent.

But unlike the 2009 financial crisis that rocked Dubai, the investment and advisory firm says the market is "smarter" this time around. The group says investors are more cautious and regulations have improved.