Sometimes in the nation's capital, getting answers to the simplest questions can be the biggest challenge.

The Washington Examiner recently requested from the General Services Administration data on the 10 cities with the most vacant federally owned or leased property.

As the government's housekeeping agency, GSA is the logical place to seek such information because it manages the Federal Real Property Profile, which it describes as "the federal government's only database of all real property under the custody or control of executive branch agencies."

But the information sought by the Examiner on those 10 cities is not available in the FRPP, according to a GSA spokesman.

The FRPP was created in 2004 as a central source for information on condition, use, operating costs and other data intended to help the federal government manage its property.

But the database is full of inaccuracies, according to the Government Accountability Office, including moldy and flood-damaged buildings reported in good condition, empty structures reported as occupied, and official operating costs that differ wildly from what it really costs to maintain property.

There has been "some progress ... in obtaining data about federal real property, the government still continues to lack consistent, accurate, and useful data that could support strategic decision-making about federal real property," GAO said in a recent report.

The FRPP's unreliability is one of the greatest challenges in managing the government's property, David Wise, director of physical infrastructure at GAO, told the Examiner.

"Property 101 is, kind of, to know what you have and how it's being used," Wise said.

The GAO's Feb. 5 report found the FRPP is also unreliable when it comes to structures other than buildings like landing strips and parking garages.

The GAO reviewed property belonging to the the departments of agriculture, energy, interior, transportation and veterans affairs, which together manage an estimated 83 percent of federal civilian structures.

Some decrepit properties were listed as being in good condition or as having no operating costs if they were bound for disposal, so the agency could free up money to put toward other structures, according to GAO.

Others weren't located where they were listed, and in one case a facility listed as a single structure was actually several, GAO said.

The FRPP's problems have a variety of causes, beginning with the fact that data is reported differently from one agency to another. Some, for example, group roads together and list them as one road, while others report each individually.

And because various agencies report the data differently, the numbers can't be compared across the entire government.

"This kind of variation undermines the reliability of both the aggregated agency and FRPP data," the GAO report said.

Several congressional hearings last year focused on these problems.

“These findings raised concern that the FRPP is not a useful tool for describing the nature, use, and extent of excess and underutilized federal real property," GAO told subcommittee of the House Committee on Oversight and Government Reform last April.

"Because key data elements are not reported uniformly, they can have no collective meaning when amassed in a single database," the GAO said in a June 2012 report on which its April 2013 testimony was based.

At least 3,000 civilian buildings sit empty or barely used around the country, according to the database.

Excess buildings costs taxpayers about $1.6 billion annually, but often take years to get rid of, according to GAO.

A long list of bureaucratic rules for disposing of such property, plus faulty data about it, have landed the government's real estate portfolio on GAO's "high risk" list for several years running.

GAO designates programs "high risk" if they are vulnerable to fraud, waste, or mismanagement, or they are most in need of reform.

The GSA is "aggressively" helping agencies get rid of their unused property, including holding auctions, filling vacant buildings with tenants and proposing new uses for unused space, according to spokesman Dan Cruz.

The agency has helped dispose of 28,121 acres of excess land since 2010, Cruz said.

"There is still more that needs to be done, and GSA is actively working with all federal landholding agencies to identify unneeded assets and move them into the disposal process," he said.

The GSA manages the FRPP, but the rules governing data collection are determined by the Federal Real Property Council, which includes GSA and other landholding agencies.

The FRPC is chaired by the White House Office of Management and Budget, which referred questions about the FRPP to GSA.

The council is working on standardizing data reporting so the FRPP is more reliable for buildings and structures, Cruz said.