Brits Abroad By Ben Richardson Business reporter, BBC News in Sofia

Sofia has kept its charms despite years behind the Iron Curtain

James Flint is a property developer in Bulgaria who does not mince his words when talking about some of the would-be UK real estate investors jetting in.

"The way many of them act, there must be a locker at Heathrow where they check their brains in before boarding a flight," he says over a drink in a worn but prettily European quarter of Sofia.

"It's not rocket science, and it's an exciting time, but get it wrong and you will lose money," explains the Birmingham-born 35-year-old who lived in Spain before moving to the Balkans.

Signed up

Bulgaria is due to join the European Union on 1 January.

But while the UK government is preparing to bar entry to many workers from both Bulgaria and Romania, Brits themselves are going gaga over investment opportunities in the two former Eastern Bloc nations.

UK television programmes such as Channel 4's A Place in the Sun have been flagging up their potential. Magazines and newspapers have been filled with tales of Mediterranean coastlines and Alpine ski slopes - at a fraction of the cost.

We are in Sofia for a weekend break. We wanted to get a feel for what is happening over here Hayz Herdman and wife Dawn

The IPPR's research into Brits Abroad, revealed on the BBC's News website supports other findings that when it comes to property, the EU's newest members were gaining in popularity.

One British lender estimates that Bulgaria will account for a quarter of overseas mortgages broker business by 2020. Romania was named by A Place in the Sun as best place for a return - with claims of a 400% return on property over the coming decade.

Driving this expected boom, experts say, are budget airline flights, massive infrastructure spending, an increase in the local standard of living - and the expected take-up of the Euro.

Ground work

Walk up and down Vitosha Prospekt, Sofia's main shopping precinct, and it's not difficult to spot foreigners checking out the housing market.

NUMBER OF BRITS ABROAD Bulgaria 800 full time/ 10,000 part time Romania 4,500 full time/ 5,000 part time Hungary 5,200 full time/ 5,800 part time Source: IPPR

Clutching a guide book and watching his wife Dawn get her shoes polished is Hayz Herdman, a 33-year-old New Zealander who lives in St Albans, north of London. They have been investing in property for the best part of a decade.

"We are over for a weekend break - and one reason is we wanted to get a feel for what is happening over here," he said.

"I thought about buying out here about two years ago, but was a bit too apprehensive.

"Now, I am worried I've missed the boat on the big gains."

Both his fears - and the warnings of people putting up money before realising the risks - may be justified.

Landscape shift

Expected investment returns from Bulgarian properties have fallen from 116% in 2005, to about 35% in the first nine months of this year, according to property analysts Assetz.

The market is slowing because more new properties are becoming available, press reports of mis-selling and questions about the genuine desirability of some holiday locations.

Often, investors base their foreign buying on the idea that they will be able to rent out the property, covering mortgage and renovation costs.

You can still buy up Budapest's equivalent of Kensington and Chelsea for a fraction of the cost Gordon Cross, Budapest Lets

Many companies have been promising exceptional returns for anyone willing to invest in Bulgaria's rising property market.

The reality is often a lot less generous and depends on finding tourists, business people, students or locals willing to pay up and move in.

There are also questions over whether the rapid development of resorts such as Sunny Beach, on the Bulgaria's Black Sea coast, and Bansko in its mountains will attract or put off tourists.

Kremena Stankova works for a German tourist company that sells holidays to Sunny Beach. She says her job is being made harder by the development.

"People come to me and say 'We used to love it here because it was quiet and unspoilt, but now it's has become like another city'," the 32-year-old explains.

Major wobbles

One of the biggest problems for ex-pat investors in foreign housing markets is that the value of their property can be affected by local factors over which they have no control.

Nowhere is this more evident than in Hungary, which joined the EU in May 2004.

After an initial surge in property prices in the lead up to membership, values hit a plateau before dipping amid Hungary's economic problems. These problems not only weakened the currency, making joining the Euro less likely, they also sparked riots.

AVERAGE SALE PRICE OF BULGARIAN FLATS Sofia 750 - 1,100 euros/m2 Burgas 650 - 950 euros Varna 780 - 1,200 euros Plovdiv 400 - 650 euros Source: Foros

Gordon Cross is a former management consultant who develops property in Budapest with his girlfriend Kati.

He says Budapest's property market is underpinned by steady demand from foreign students coming to its world-class universities and by multinational firms setting up regional headquarters.

Even so, Mr Cross reckons that an annual yield of 7% is a good return for a flat in Budapest.

"If you are looking to make quick money then don't come to Budapest," he explains. "But if you are willing to take a long-term view, of say 10 years, then you are still getting a good investment."

"You can still buy up Budapest's equivalent of Kensington and Chelsea for a fraction of the cost. The key is to know exactly what you are buying."

Wide-eyed

And this is where many UK investors fall short, often buying unseen apartments from plans and trusting to luck that they are getting a good deal, says Assetz's managing director Stuart Law.

The secret is not to do anything here that that you wouldn't do at home James Flint, Sofiacasa

People buy because they expect prices to rise. This is not investment - but speculation, he warns. Better options exist, for those who know the local land and property markets.

"The secret is not to do anything here that you wouldn't do at home," says James Flint. "Know your market and do your research. Then buy a good quality property that you can market.