Housing and real estate are going through a period of systemic change that could reshape how we think about the sector in years to come.

What's happening: Prices in the largest U.S. cities have stagnated for the first time since 2011, mortgage applications are falling and even ultra low interest rates have not been enough to lure buyers back to the market, data shows.

What it means: "Mortgage interest rates in many cities aren't the major challenge for house buyers anymore," Claudio Saputelli, head of real estate at UBS Global Wealth Management, said in the asset manager's annual Global Real Estate Bubble Index.

"Many households simply lack the funds required to meet the banks' financing criteria, which we believe poses one of the biggest risks to property values in urban centers."

Buying a 650-square-foot apartment exceeds the budget of people who earn the average annual income in the highly skilled service sector in most world cities, per UBS.

Why it matters: It's the end of the boom, Saputelli and Matthias Holzhey, head of Swiss real estate investments, write. The exponential rise in housing prices combined with a lack of major wage gains for average American workers over the last 3 decades may have finally topped the fast-growing urban housing market.

Real prices in all 4 of 2016's top-ranking cities have fallen. On average they are down by 10% from their respective peaks.

"Owning residential property in global cities has been a sure road to wealth accumulation. However ... real price appreciation can no longer be taken for granted."

Details: Currently, the analysts see 7 cities at high risk of being in a real estate bubble, but more importantly they see a rethink of housing as an asset taking place across the world's developed economies.

While the U.S. housing bubble risk has receded as prices have stagnated, the eurozone is now at the greatest risk of a housing bubble, as ultra-low interest rates have helped push many of Europe's cities to price levels reminiscent of bubbles past, UBS analysts said in the paper.

Go deeper: U.S. mortgage rates rise while applications and home prices slow