Owners of properties worth more than about $182,000 will soon pay a new graduated tax, the first major fiscal reform since President Oscar Arias took office in May 2006.

Approved by lawmakers late last week, the tax will raise an estimated ¢9.7 billion (about $18 million) a year to fund the state's efforts to rebuild substandard housing, according to an estimate by the Legislative Assembly's budget analysis department.

The bill, which still must be signed by Arias, imposes an annual 0.25 percent tax on properties worth between ¢100 million ($182,000) and ¢250 million ($454,500). So a person owning a $200,000 house would pay an additional $500 a year in property taxes.

The new property tax increases with the property's value, up to a 0.55 percent levy on properties worth more than ¢1.5 billion ($2.7 million).

An estimated 6,500 properties will be affected by the new tax, the government said.

The taxes must be paid in the first 15 days of each year. Properties belonging to the government, public institutions, churches and non-profit organizations are exempt.

The revenue will go to the National Housing Mortgage Bank (BANHVI), which offers grants to poor families looking to rebuild their homes and neighborhoods.

About 40,000 families live in substandard housing in Costa Rica, according to BANHVI spokeswoman Susan Otárola.