A photo caption with a Nov. 19 Real Estate article on researching old houses incorrectly said that the Marquis de Lafayette had once rented a house at 1629 16th St. NW. The renter was a descendant of the Revolutionary War general. Also, an accompanying article incorrectly said that the Historical Society of Washington, D.C., had put together a research guide with the Washingtoniana Division of the D.C. Public Library. The guide was created by Matthew Gilmore when he was at the division; the society was not involved. (Published 11/30/2005)

The handsome gray building at 1629 16th St. NW was built in an architectural style known as Richardson Romanesque, popular in the late 19th century and characterized by massive stone construction and deep-set arched doorways. Inside, five upscale condominiums offer all the 21st-century amenities the Washington professional could want: elevator, high ceilings, granite counters, Sub-Zero fridges, gas fireplaces and sleek faucets.

Listing the condos at $450,000 to $2.5 million, developer Ken Taylor wanted to offer potential buyers something else: a sense of history.

Well-off, educated home buyers often think historical background "adds a different level of intrigue to the property," he said. "The more information we have to give them, the more they like it."

Seven blocks away, the owner of a red brick rowhouse on 13th St. NW is also curious. Scott Pomeroy has lived there for 17 years and is fixing his house up. He already had some sense of his home's past; for example, he knew that years ago the building had been divided into medical offices, because of its proximity to Children's Hospital. But he wanted to know more.

Both men consulted a professional architectural historian, Paul K. Williams, whose company, Kelsey & Associates, has been researching historical buildings in the Washington area since 1991.

But Williams and other experts say any homeowner who wants to delve into a house's history can make use of a wide range of publicly available resources. Matthew Gilmore, who maintains a Web site on District history, has taught classes on researching houses for the D.C. Preservation League and says most of his students are new homeowners.

Maps, deeds, building permits, census data, and many other records are on file in different jurisdictions throughout the area; libraries and historical groups can provide guidance that, combined with persistence and some luck, can lead a house to yield its secrets.

Research starts with a walk through the house, looking for clues. Variations in stone or brickwork could signify an old window, or an old staircase, or an old fireplace, and give a sense of what might be in the building's past.

The house on 16th Street held relatively few clues, Williams said; it had been too thoroughly remodeled over the years. So he took the next step all researchers should take -- going to the local library or historical society. In the District the primary source of information is the Washingtoniana room at the Martin Luther King Jr. Memorial Library at 901 G St. NW.

There, Williams consulted old maps to pin down the property's square and lot numbers, the legal definition of any property in the District. Being south of Florida Avenue, the 16th Street building still had the square number assigned in the original design by Pierre L'Enfant. Other parts of the District have been renumbered, but those numbers can be tracked over time by checking subsequent maps.

Williams then looked up the property in the library's archive of microfilmed building permits. From them, he learned that the house's first owners, Henry N. Manney and his wife, Anteinetta, had it built in 1887 for the then-steep sum of $15,000. It was designed by architect Robert I. Fleming, and the builder was Frank N. Carver. The house was 50 feet deep by 28 feet wide, with an ornate slate and tin roof and a facade in the front to give the illusion it was taller than it was.

Subsequent permits, also on file, revealed the house's carriage house, now the fifth condo, was built in 1904 as servants' quarters. The pieces of the house's history were starting to fall into place.

To find out who Manney was, Williams went to the city directory, also available on microfilm in the Washingtoniana room. City directories, available in many urban areas, list residents, not necessarily owners; some people listed may be renters. Some directories are organized by street as well as by last name. They often give residents' occupations, which can point to other resources.

Manney's listing revealed he was in the Navy. So Williams went to military Web sites, where he learned that Manney became a captain and later moved to San Diego -- without Anteinetta, from whom he had apparently been divorced. He eventually became a city councilman there.

Continuing his research in the Washingtoniana room, Williams went to census reports. These show the number of people in every house; their names, ages and relationships; whether servants lived on the property or whether there was a mortgage on the house; and so on. "All the names that you can just get out of a directory sort of come to life," Williams said.

To find data on a particular property, he said, the researcher needs to identify it on census maps. (The 1930 census is the most recent one for which personal data is available; for privacy reasons, the federal government does not make specific data public until 72 years after it is collected.) The maps, which divide the District into enumeration districts, are old and sometimes hard to read, so some guesswork may be required to find the right roll of microfilm containing the census report.

Other maps also help in piecing together a sense of the building's occupants and use. Available at Washingtoniana, and many historical agencies, are maps that the Sanborn Fire Insurance Co. began publishing in the mid-19th century. Because the company was trying to determine and document the risk of fire, these maps noted how close structures were to one another, what materials they were built from, and what they might be likely to contain. These maps can sometimes also be found online, often through university or local libraries.

Property deeds, at the Recorder of Deeds, at 515 D St. NW, showed transfers of property. Histories and biographies in the library stacks fleshed out the picture.

Eventually, Williams learned that the 16th Street house was sold in 1896, to Mr. and Mrs. John C. O'Donnell. O'Donnell had no job listing and may have been retired. In 1917 a steam heating system was installed. The carriage house, behind the main building, was home to three or four servants over the years. By 1920, the house was being rented. One tenant was the Count de Chambrun, a French colonel and descendant of Revolutionary War hero Gen. Marquis de Lafayette who was serving as a legal adviser in the French Embassy.

At some point -- probably during World War II, when Washington was flooded with government workers seeking temporary housing -- the house was turned into a boardinghouse. "It was kind of your patriotic duty to take your big house and convert it," Williams said. In 1978, it became an apartment building. And then it went condo.

Unlike the case with the 16th Street houses, an initial walk through 2035 13th Street revealed many clues to the building's past.

For example, Williams could tell the whole block was built in groups of three to five houses because the pattern of the brick facade indicates the bricks were laid across several buildings at a time.

In the front bedroom on the second floor, a line on the wall showed that the ceiling used to be lower. In the basement there were indications of where a staircase used to descend.

With Williams's aid, Pomeroy and his fiancee, Lydia Charles, were preparing to start the search for their home's past life.

"We're looking forward to the mystery being unraveled," said Charles.

Williams agreed: "I love a good mystery," he said.

In addition to using maps, directories, and microfilmed records, Williams pointed out other sources of information that might be useful. For example, since the house is located down the street from the old Children's Hospital, it might show up in photographs of the hospital in old histories, newspapers or magazines. Similar possibilities would exist for a house near an old church, school or public building.

If a building had a prominent owner, photos of it may have run in newspapers or newsletters. The stature of a District resident listed in the census or city directory can be ascertained through books available at Washingtoniana, including archival copies of "Who's Who in the Nation's Capital" and "Prominent Personages of the Nation's Capital," also available at libraries.

Homeowners often hope to find facade drawings and floor plans in old records, Williams said, but in the District, at least, these are rarely available.

There are other holes in information available. The 1890 census records for the District were destroyed in a fire. People lied to census enumerators. Some buildings went up without permits. And records can get lost or not properly recorded.

Finally, Williams warned, be careful about clues or what you think you know about your house. In the 1920 and 1930s, for example, the popularity of Colonial Williamsburg inspired a trend to build houses to appear older than they were. In Georgetown, in particular, he said, some homes of that era were built in the style of 1840s with salvaged materials.

If the search seems daunting, a local historical society or library staff might be able to point to someone who does the research for a fee. Richard Guy Wilson, a professor of architectural history at the University of Virginia, suggests checking universities for an American studies or historical preservation programs; while students generally won't research your house for free, they might not charge as much as a professional.

Despite the difference in exterior color, the bricks of Lydia Charles and Scott Pomeroy's home line up with those of the adjacent house, showing they were built at the same time.The exterior of the newly renovated condo building at 1629 16th St. NW. Research found that the building dates to 1887, and once was rented by the Marquis de Lafayette. Architectural historian Paul K. Williams, left, and Scott Pomeroy examine brickwork in back of Pomeroy's 13th Street home. Historian Paul K. Williams studies the framework of the Pomeroy home on 13th Street NW.