And annual house price growth here is now less than half of what it was six months ago.

Confirming fears of a significant cooling of the province's property market, the Nationwide Building Society quarterly regional house price report shows that house prices here actually fell by 0.2% in the last three months of 2007. This is the first fall recorded in Northern Ireland for six years, it said.

According to statistics released this morning, the average house in Northern Ireland is worth £224,816.

The building society's researchers found that the province's property market saw the biggest slowdown in annual house price growth in the UK.

Last year started well when prices in Northern Ireland grew at an average annual rate of over 55% for the first six months. This slowed drastically when the growth rate dropped to an average of 24.2% by the end of the year.

But looking at the year as a whole the value of a property in Northern Ireland still increased by an average £120 per day.

The report warned that house price growth expectations will cool demand rapidly this year.

"Annual house price growth is now less than half that of six months ago. Indeed in the first half of 2007 prices in Northern Ireland grew at an average annual rate of over 55%," it said.

It also highlighted a "severe deterioration in affordability" as a major factor.

Fionnuala Earley, Nationwide's chief economist, said that despite the market slowdown, Northern Ireland still had the fastest house price growth in the UK over the whole year.

The research found that Belfast was the most expensive area to buy a property while the west of the province was the cheapest. The north east saw the strongest price growth while the west saw the weakest.