Singapore property prices surged 50 percent between 2007 and 2011, driven partly by foreign buying. While developers reacted to the rise by ramping up homebuilding, the market now faces oversupply.

Nomura analysts Min Chow Sai and Paul Lin said a surge in the number of apartments expected to be put up for sale next year will curb house-price increases and some developers may even have to slash prices.

They expect the number of homes due for completion next year could reach 42,309, including 24,551 public-housing units built by the government. This compares with the estimated 21,859 units completed this year and the average annual housing demand of just under 20,000 units since 2001.

"While we have been highlighting supply risk for some time, we believe 2013 could mark the beginning of the "Day of Reckoning"," they said in a report published on Tuesday. "Coupled with tougher restrictions on home purchases imposed by the government, we expect developers to offer more discounts and incentives in 2013 to move inventory."

To cool the housing market, Singapore's government has introduced a number of measures in recent years such as higher taxes for overseas buyers. In October, it set a cap on the tenure of a home loan.

The latest measures on home loans have already had a noticeable effect, with private property sales in the primary market plunging 26 percent in October from the previous month, according to official data.

(Read more: Why a Slump in Deals Won't Hurt Singapore Home Prices)

Sai and Lin said they see increased inventory risk for residential developers and recommend investing in those developers with low inventory risk such as City Developments, UOL Group and Keppel Land .

Watch Out, Hong Kong

In Hong Kong, where house prices have climbed 20 percent so far this year on record low mortgage rates and an inflow of foreign money, affordability may become a serious issue, Nomura analysts Paul Louie and Zita Qin said in a separate report published on Wednesday.

This year's sharp rise in house prices follow a 60 percent increase over the past decade.

While other analysts are forecasting further gains in 2013, Louie and Qin say this is unlikely because income growth seems to be slowing along with the economy.

Hong Kong's economy expanded 1.3 percent in the third quarter from the same period last year. While this is better than expected, the government revised its full-year 2012 economic growth forecast to 1.2 percent from 1-2 percent, down sharply from a 4.9 percent expansion in 2011.

Meanwhile, private median household income rose by 7.1 percent year-on-year in the second quarter, but this is much slower than the 12 percent annual increase in incomes in the same period last year, the Nomura analysts said.

Slideshow: The World's Hottest Real Estate Markets

"Having peaked out at 14.8 percent year-on-year in December 2011, the household income growth rate has slowed for two quarters already," Louie and Qin said. "Can home prices keep going up? While this is possible, it is not probable."

They expect house prices to rise only 5 percent over the next 12 months at best.

"The combination of events that needs to take place for prices to continue going up means we are walking a real tightrope. We expect very muted growth for the next two years with home prices merely trending sideways," he added.

Hong Kong's housing market is among the most expensive in the world, partly driven by buyers from mainland China who account for 20 percent of total market transactions. To make housing more affordable to the broader population, the government has put in place a slew of policies since November 2010.

(Read more: Why Hong Kong's Property Crackdown Won't Dent Home Prices)

Despite the risks, some analysts still expect home prices to continue rising in Hong Kong and Singapore over the next 12 months.

Chua Yang Liang, head of Asia Pacific research for Jones Lang Lasalle, a real estate advisory firm in Singapore, said the liquidity created by aggressive monetary stimulus by the U.S. Federal Reserve and attractive mortgage rates will support prices.

Hong Kong ties its monetary policy and currency to that of the United States', therefore its interest rates tracks that of the U.S. Fed funds rate.

"There could be more market liquidity and a prolonged period of low interest rates," he said. "These factors could contribute to an upward bias towards capital values in the foreseeable future."

—By CNBC's Jean Chua.