As a result of the state's mistake, which officials acknolwedge, the city issued annual tax bills the past three years that were thousands of dollars lower than they should have been.
On Friday, after the state recalculated the value going back to 2009, Marci De Vries learned just how much in back taxes she and her husband will owe on the South Hanover Street property: $7,585.
"I feel like I got punched in the gut," said De Vries, who plans to appeal the retroactive 65 percent assessment increase. "This is unfair. They made the mistake. They didn't follow through. Now I have to pay for that?"
Across Baltimore, more than 300 properties have been combined in the past five years, records show. And now that an analysis by The Baltimore Sun has identified two cases where the state assessments agency failed to adjust a home's assessed value after a consolidation, officials say they're planning to conduct a review of other consolidations to ferret out any additional errors.
"This certainly would emphasize the fact [that a review] should be done," said Owen C. Charles, deputy director of the state Department of Assessments and Taxation.
The Sun confirmed the deficient assessments by comparing a list of consolidated properties obtained from the city to tax records. Earlier analysis of vacant properties and tax credits by The Sun revealed hundreds of other homes in Baltimore that have paid less than their share of annual property taxes – analysis done using data contained in tthe government's own files.
One challenge facing the assessments agency, officials say, is a shortage of staff. Assessors have so many accounts to juggle that they lack time for the kinds of visual checks that could reveal if, say, a home is being valued based on a portion of its actual size.
Charles said he doesn't know exactly what happened with the Hanover Street house owned by De Vries and her husband, Andrew Todtz.
"In this particular case, you're looking at a situation where the value [of both houses] simply wasn't combined," Charles said. The same veteran assessor was responsible for both mistaken assessments, he said.
In the first case, also in Federal Hill, the owner combined three rowhouses on East Montgomery Street. Yet for three years, the home's total value was calculated using the smaller footprint of just one of the houses, apparently because of a clerical error.
The owner of the Montgomery Street house, developer Blake Cordish, owes an additional $14,000 in property tax for the past three years, according to online city records. Cordish did not respond to a message seeking comment.
De Vries and Todtz say they were shocked to hear last week that the state is now putting their home's value at $583,000 — considerably higher than $352,100, where the assessment stood for three years, until The Sun's inquiry.
"We want to pay our fair share, but we don't want to be penalized for doing things the right way — or what we thought was the right way," said Todtz, co-founder of a construction company.
The couple says they paid their taxes and obtained all necessary permits to combine the homes into one residence. "We weren't trying to sneak or hide anything," said De Vries, who owns a web marketing firm.
Todtz says he even paid twice for a $729 city construction permit. In late 2008, the city issued a stop-work order because the zoning board had mistakenly approved the project without a hearing. Todtz was denied a refund, he says, forcing him to pay for a second permit after the board's final approval.
It was in 2008 that the couple legally consolidated the two brick rowhouses in the 1200 block of S. Hanover into a single parcel. Assessment records show that before the merger, the state valued one house at $351,600 and the other at $366,840.
The following year, one lot vanished from the tax rolls, having been absorbed by the other. Yet the combined lot received a new assessment of just $352,100, even though in the state's eyes the two homes had been worth a total of more than $700,000 as separate properties.
De Vries said they had noticed the drop. "We did check it out because it seemed weird," she said. But she said they were told by other property owners who'd been through consolidations that the new value is customarily well below the total value of the pre-existing parcels.
"We just thought it was normal," she said.
They also assumed the low assessment reflected the plummeting real estate market, as well as demolition they did to the back of one of the houses to make way for an addition.
But Charles, the assessments official, looked into the matter this month and discovered it was a mistake. He said the combined home's values have now been revised, dating back to the 2009-10 tax year. Their home's value is set to rise again, slightly, in the coming tax year.
Todtz says he has no objection to a higher assessment going forward. But he and his wife hope an appeal will succeed in rolling back the unexpected increases from past years.
De Vries and Todtz say they love their home, with its exposed brick walls, walk-in closet, expansive kitchen and 20-foot ceiling in the family room, where their 41/2- year-old son Jacob plays. The house is about 28 feet wide, with a large back patio.
The couple says the house is a testament to their desire to stay and invest in the city, rather than move to the suburbs like many young families. But the assessment shock has soured their mood.
"We're having second thoughts now," Todtz said.
About this series
"Taxing Baltimore" is a series of occasional articles examining Baltimore's property tax rate, the highest in the state. To see archived articles from this series as well as a searchable database and a photo gallery of the properties with the highest tax bills, go to baltimoresun.com.