* Region's house prices soar over past decade
* Low interest rates and tax perks encourage buyers
* Governments worried by booming market
* Graphic: http://tmsnrt.rs/2k1TfAt
OSLO/STOCKHOLM/COPENHAGEN, Feb 20 (Reuters) - Joakim Bakka, a 29-year-old shop worker, was so desperate to get into Norway's booming housing market that he was prepared to borrow money at 13 percent for a deposit to buy a home.
It would have been risky but he felt he had no choice. Bakka, from the Norwegian city of Drammen, is not alone in considering such drastic steps.
Scandinavians are taking increasing risks on housing as prices have soared over the last decade, fuelled by low interest rates and tax perks that have encouraged people to buy homes rather than rent.
Household debt levels have risen sharply, worrying governments that have tried without success to cool the market.
"Even though my partner and I have full-time jobs, we were not able to find enough cash for a deposit, so as an emergency solution, we applied for a consumer loan of 100,000 crowns ($12,000)," Bakka told Reuters.
"In the end we did not have to use it, as we managed to get a loan from a communal public bank at about 3 percent. But it was not difficult at all to get a consumer loan."
House prices show no signs of slowing. In Norway they grew 12.4 percent year-on-year in January after a record high of 12.8 percent in December. Swedish house prices rose 9 percent year-on-year in January.
In Denmark, prices of owner-occupied flats have risen between 50 and 75 percent in Copenhagen since 2012, according to mortgage lender Nykredit, compared with 37 percent outside the capital.
Sofie Borbiconi, 29, is a radio host looking to buy a flat in Copenhagen.
"It is crazy. When we visit flats, we have to queue in long lines to get in," she said. "You have to use unconventional measures," she added, although she preferred to keep them secret.
Governments are concerned. Denmark tops the OECD list of developed nations with the most household debt relative to disposable income, with Norway third and Sweden fifth.
The International Monetary Fund has said Sweden's high household debt levels could stifle other areas of the economy.
"Swedish housing prices are historically high, implying downside risk to consumption, even as housing shortages lower the risk of a major decline," the IMF said in September.
Both Denmark and Sweden have seen house prices collapse before. In 2008, the global crisis punctured a Danish housing bubble, triggering a local banking crisis that wiped out over a dozen lenders.
Swedish house prices fell 20 percent in two years in the early 90s, contributing to the nationalisation of what is now the region's biggest lender, Nordea, which has since been re-privatised.
While high prices are encouraging new homebuilding in some parts of Scandinavia, easing upward pressure on prices, the shortage of housing, notably in Sweden, and high demand due to immigration is expected to keep prices high.
"What is special in Sweden is that we have negative rates and very, very strong growth. We are one of the few countries that has that or has ever had that," Erik Thedéen, head of the Swedish Financial Supervisory Authority, told Swedish radio last week. "This creates what I have called a greenhouse for growing debt."
Nevertheless governments have been trying to calm the market. Norway in 2015 reduced the amount of money housebuyers can borrow from banks to 85 percent from 90 percent of the purchase price.
This year the government introduced new rules, including capping borrowing at less than five times a householder's income and stipulating that buyers of second homes in Oslo must have a deposit of at least 40 percent compared to 15 percent elsewhere.
In June, Sweden banned interest-only mortgages.
Denmark has proposed new tax rules that should reduce swings in housing prices from 2020 onwards, something the central bank and economists have called for since a freeze on house taxes was imposed in 2001.
But the measures have had little impact.
"People got very scared when the bank rules were changed last year. But now we sell flats at record prices and lots of people show up at viewings," said Fredrik Flodin, a real estate agent in Stockholm.
Norwegian home building is set to reach a 38-year high of 38,000 homes, up from a previous estimate of 33,000.
Snorre Storset, the chief executive of Nordea in Norway, said some buyers were hit by rules restricting mortgages to five times their incomes.
"But the underlying demand is so strong that we don't believe prices will stop rising in the short term," he told Reuters.
Ultimately, raising interest rates may be the only tool left for central banks. But none of them can, partly because rates are low internationally and partly because they want to prevent their currencies from appreciating.
In Norway, the central bank expects rates to stay at their current record low of 0.50 percent, "in the period ahead" to help sustain a weak economic recovery, despite an overheating housing market.
In Sweden, the Riksbank says urgent measures are needed to cool housing prices. Still, its key deposit rate is set at a negative 0.50 percent, with more cuts possible as it fears a global recovery could be tripped up by Brexit, slower growth in Europe and a more protectionist United States.
In Denmark, the central bank has left its key deposit rate at a negative 0.65 percent since February last year. Its top priority is maintaining the country's three-decade-old currency peg against the euro and so it dislikes anything that might push up the crown too much.
"Over the past year I have sold three parking spaces: one for 1,050,000 crowns, one for 900,000 crowns and one for 850,000 crowns," said Jonas Lind, a real estate agent in Stockholm.
"This is unheard of, and I have been in the business for eight-and-a-half years. People see this as a good investment, because it is cheap to borrow money and they can rent these spaces out."
(Additional reporting by Stine Jacobsen in Copenhagen, Terje Solsvik and Gwladys Fouche in Oslo; writing by Gwladys Fouche; editing by Giles Elgood)