GARDEN CITY, N.Y. (CBSNewYork) – Notifications in the mail about new property tax assessments is causing sticker shock for some Nassau County residents as the first major overhaul of property values in the county in nearly a decade rolls out.

Unfreezing the tax rolls means half go down, but the other half will go up, reports CBS2’s Carolyn Gusoff.

Letters were sent to all 380,000 Nassau County homes in the first property reassessment in eight years. The letters contain the new property value but not the impact on taxpayers’ payments.

“They more than doubled my assessment,” said resident Jack Lyons. “Right now, I don’t understand how they did that.”

County Assessor David Moog says a follow up letter will contain each homes tax impact and a new website, “Ask The County Assessor,” will enable residents to compare neighbors’ values or make an appointment at new outreach centers to ask questions.

The following satellite office locations will be open Monday through Thursday from 9:30 a.m. to 5:15 p.m.:

  • Christopher Morley Park in Roslyn.
  • Eisenhower Park Administration building in Westbury.
  • Public Safety Center at 1194 Prospect Ave. in Westbury.
  • Nickerson Beach Adminstration Building in Lido Beach.

“The properties are valued fairly close to what the sales of the properties are out there,” said Moog.

County Executive Laura Curran said the overhaul was needed because for years the county’s been locked into indefensible, inaccurate assessments.

“We are hemorrhaging money because of it, that is why we are in the fiscal crisis we are in, so fixing the assessment is key to getting our fiscal house in order,” she said.

The timing is tough to take as the federal tax code eliminates much of the property tax destructibility.

“Seniors on a fixed income, single parent households, working families – if they see a sizable tax increase, and some of them definitely will, it could be enough for some of them to say, ‘I’ve had enough, I’m out of here,’” said Nassau County legislature presiding officer Richard Nicolello.

ALSO SEE: Why The Nassau County Assessment As Necessary

“It’s an awful lot to swallow at once and I wasn’t expecting it, and then got a letter today saying my valuation of my house had almost doubled,” said Garden City resident Joe Donovan.

Double the valuation does not mean double the taxes. The impact varies per home.

Curran is asking the state to allow a five year phase of the new tax assessments to soften any blow.

Homeowners will still have the right to grieve but the county officials believe this time, they got it right.

The county claims it isn’t making any money on the reassessment, which does not add any revenue to county coffers.