The DC row house dictionary.
Every term, in plain English.

A listing says "bay-front Victorian with English basement and C of O." Half of that sentence may not mean what you think, and one part of it is a legal document.

Here is every term in alphabetical order, then the floor plans and the styles. Where a term has a history, I give it. Where it has a rule, I name the agency that sets it.

A

Alley dwelling

A small house built facing an alley inside a city block, rather than on a street. DC effectively stopped new alley construction in 1892, Hoagland writes, and about 108 alley dwellings survive in the old city.

Areaway

A sunken space at the front or back of a house that reaches the basement door from outside, with steps down from the sidewalk or yard.

Assessment

The value the DC Office of Tax and Revenue puts on a property each year for property tax. It is not the sale price: DC row houses regularly sell above or below it.

Assessment Cap Credit

A DC credit that limits a homesteaded property's taxable assessment to a 10% rise per year. A buyer keeps the seller's credit only for the half-year of the purchase.

B

Back building

A narrower rear wing behind the main part of the house, usually holding the kitchen, with a bathroom or bedroom above.

Balustrade

A railing made of a row of short posts, called balusters, topped by a rail. Seen on porches, stoops and rooflines.

Bay window

A section of the front wall that projects outward, with windows on three sides. A January 1871 law let bays project four feet past the building line, Hoagland writes, and by 1877 bays of two stories or more had to be masonry.

Bay-front

A row house whose front has a projecting bay, usually the full height of the house. The dominant DC row house front from the late 1870s to about 1905.

Belt course

A horizontal band of brick or stone across the front wall, often at a floor line. Also called a string course.

Bracket

A decorative support under the roof edge or a window top. A row of brackets under the cornice marks an Italianate front.

Brick bond

The pattern the bricks are laid in. Running bond shows only the long sides. Common bond adds a row of brick ends every few rows. Flemish bond alternates long sides and ends in every row.

Brownstone

A reddish-brown sandstone used for fronts, steps and trim. Less common in DC than in New York; most DC fronts are brick.

Building line

The line, set by the city, that the front wall of a house sits on. Bays, porches and steps may project past it into public space, within limits.

C

Cast-iron stair

An exterior stair of cast iron leading to a raised front door, common on Victorian fronts.

Certificate of occupancy (C of O)

A document from the DC Department of Buildings confirming that a building's use meets zoning and the construction codes. Renting an English basement under an occupied house requires one. Search past certificates by address in the Department of Buildings eRecords.

Chimney and flue

The chimney is the brick stack. The flue is the passage inside it. Many old flues are unlined or closed off.

Condo unit

One unit inside a row house that has been divided into separately owned units. You own the unit and a share of the common elements, which can include the roof and the facade. See fee simple.

Conversion

A row house the DC assessor records as divided into units, under use code 024 (fewer than five units). The city records 6,577 row houses this way.

Coping

The cap along the top of a parapet or party wall that keeps water out of the wall.

Corbeling

Brick laid in courses that step outward, one beyond the other. In DC it was the cheap, fireproof way to build a decorative cornice, Hoagland writes.

Cornice

The decorative band along the top of the front wall, where the wall meets the roof.

Cresting

A decorative iron railing along the top of a roof or bay.

D

Dentils

A row of small, evenly spaced blocks under a cornice, like a row of teeth.

Door surround

The frame and trim around a front door: the casing, any columns or pilasters, and what sits above.

Dormer

A small window that sticks out of a sloped roof, with its own little roof.

Double-hung window

A window with two sashes that slide up and down past each other. The standard window in a DC row house.

Dumbwaiter

A small hand-pulled lift between floors, for food and dishes. Late-19th-century houses with a basement kitchen used one, Hoagland writes.

E

End of row

The house at the end of a row, with one shared wall instead of two. Period ads called it a "corner house," Hoagland notes. The MLS lists it as "End of Row/Townhouse."

English basement

Today: a lower level a half-story below the street, often with its own entrance, frequently rented as a separate unit. Renting it as a unit requires a certificate of occupancy and a Two-Family Rental license. A century ago the term meant something else, Hoagland writes: a house plan with the entrance at street level and the parlor on the floor above.

F

Fanlight

A half-round or half-oval window above a front door, often with glass set in a fan pattern.

Fee simple

Full ownership of the land and the whole building. Over the last two years, about one in eight of DC row house sales were condo units, and the rest fee simple. See condo unit.

Finial

A small pointed or rounded ornament at the top of a tower, gable or post.

Flat arch

A straight window or door top made of wedge-shaped bricks or stones. Also called a jack arch.

Flat roof

The standard DC row house roof since the 1850s, when tin roofing replaced gables, Hoagland writes. It is not truly flat: it slopes gently away from the street to drain.

Frieze

A flat horizontal band just below the cornice, often decorated.

G

Gable roof

A roof with two sloped sides that meet at a ridge. On early DC row houses the ridge runs parallel to the street.

Gutter and downspout

The channel along the roof edge that catches rain, and the pipe that carries it to the ground or the drain.

H

Half-timbering

Dark wood strips set into a light wall surface, in the manner of old English houses. On DC row houses it is decoration, not structure.

Heart pine

Dense wood from the center of old-growth longleaf pine, used for floors in many 19th-century houses.

Historic district

A neighborhood the city has designated, where exterior work that needs a building permit is reviewed by the DC Historic Preservation Office. Review turns mostly on what can be seen from the street; painting and ordinary maintenance generally need none. Work in Georgetown also goes to the U.S. Commission of Fine Arts.

Homestead deduction

A DC deduction that takes $91,950 off a principal residence's assessment for tax year 2026, a saving of $781.58. You apply for it once you live there.

Hood mold

A projecting molding over a window or door that throws rainwater clear and frames the opening. Common on Italianate fronts.

I

Interior row

A house with neighbors on both sides, sharing two party walls. Period ads called it an "inside house," Hoagland notes.

Iron fence

The low iron fence many row houses carry along the front of the parking, often original to the house.

J

Joist

One of the parallel beams that hold up a floor. In a DC row house the joists usually run from party wall to party wall.

K

Keystone

The wedge-shaped center stone at the top of an arch, often carved or made larger for show.

L

Light court

The narrow open space beside a back building. It lets daylight and air reach the middle rooms of the house.

Lintel

The beam, often stone, set across the top of a window or door opening.

M

Mansard roof

A roof with a very steep lower slope, often slate, usually with dormers. On a row house it often appears only on the front.

Membrane roof

The covering on most flat roofs today: a continuous sheet of rubber, modified bitumen or plastic, in place of the original tin.

Mortar

The material between the bricks. Older DC houses were built with soft lime mortar. Hard modern cement mortar can damage old brick, so repairs should match the original.

O

Oriel

A bay window that starts above the ground floor, supported from below by brackets or corbeling. DC's building rules first named it in 1887, Hoagland writes.

P

Pane count

How listings describe a window: "six-over-six" means six panes in the upper sash and six in the lower.

Parapet

The part of the front wall that rises above the roof line, hiding a flat roof from the street.

Parking

In DC, the strip of public land between the sidewalk and the front of the house, often planted as a front yard. The owner maintains it but does not own it. The arrangement dates to the late 1860s, Hoagland writes.

Parking pad

A paved space off the alley at the back of the lot for one or two cars. Some row houses have a rear garage instead.

Party wall

The shared wall between two row houses. DC's first building regulations, in 1791, set rules for building it and made the second builder pay the first half its cost, Hoagland writes.

Pediment

A low triangle, or a curved shape, over a door, window or the top of a front.

Pilaster

A flat, shallow column set against a wall, framing a door or the corners of a front.

Plaster and lath

The original wall finish: plaster spread over thin wood strips, before drywall.

Pocket doors

Doors that slide into the wall instead of swinging open, often between a front and back parlor.

Porch front

A two-story row house with a full-width front porch, built from 1906 into the late 1920s. Builders sold it as "Colonial."

Pressed brick

A dense, smooth, sharp-edged brick made in a mold, used on the fronts of better houses from the late 19th century.

Q

Quoins

Blocks of stone or brick at the corners of a building, set to stand out from the wall.

R

Radiator and boiler

Hot-water or steam heat: a boiler, usually in the basement, heats water that runs to radiators in each room.

Rear yard

The open part of the lot behind the house, usually reached from the back door and the alley.

Repointing

Removing worn mortar from the joints and replacing it with new mortar.

Roman brick

A long, thin brick, used on some fronts around 1900. Hoagland cites Bloomingdale rows of 1902 with Roman brick fronts.

Roof hatch

A small door in the roof, reached by a ladder, for getting onto a flat roof. Also called a scuttle; DC's 1877 building code lists it, Hoagland notes.

Rooflet

The short strip of mansard roof, in tile or slate, across the top of many porch-front houses. It is decoration, often with little or no usable space behind it.

Round arch

A window or door top shaped as a half circle. A mark of Romanesque Revival fronts.

Row house

A house joined to its neighbors by shared walls. Hoagland's definition is stricter: a house with neighbors on both sides. The word itself rarely appeared in print before 1910, she writes.

S

Sash

The frame that holds the glass in a window. A double-hung window has two.

Segmental arch

A window or door top shaped as a shallow curve, less than a half circle. Common on 19th-century brick fronts.

Shutters

Hinged panels beside a window. On many DC fronts they were added later and do not close.

Side hall

A hallway along one side of the house, from the front door to the stairs, with the rooms beside it. Houses narrower than about 16 feet usually had none, Hoagland writes.

Sidelights

The narrow windows on one or both sides of a front door.

Skylight

A window in the roof. On porch-front houses, skylights light the second-floor bathroom, Hoagland writes.

Sleeping porch

A screened or windowed porch, usually at the back on the second floor, for sleeping in hot weather. Standard on porch-front houses of the 1910s and 1920s, Hoagland writes. Many have since been enclosed as rooms.

Spalling

Brick or stone whose face is flaking or breaking off, usually from water getting in and freezing.

Square

DC's legal term for a city block. Every property's tax ID starts with its square number.

SSL

Square, suffix and lot: the ID DC uses for every property in its tax and land records.

Standing-seam metal

A metal roof of long panels joined by raised seams. Common on mansards, porches and bays.

Stoop

The steps up to a front door on a raised first floor, with a landing at the top.

T

Tower or turret

A rounded or many-sided bay that rises above the roof line, usually topped with a pointed or domed roof.

Town house

The same building as a row house. "Town house" replaced "row house" in mid-century marketing, Hoagland writes, to shed the older word's reputation.

Transom

A window above a door, or above a window, that lets in light when the door is closed. Inside older houses, transoms over bedroom doors also moved air.

U

Use code

The DC assessor's code for how a property is used. 011 is a single-family row house, 023 a flat, 024 a residential conversion of fewer than five units.

W

Winder stair

A stair that turns using wedge-shaped steps instead of a landing. Early narrow row houses fit one into the corner of a room, Hoagland writes.

Y

Year built

The year the DC assessor records for a house. When it does not know, it enters 1900, so treat a recorded 1900 as "1900 or earlier." Building permits from 1877 to 1949, at the National Archives and the DC Public Library's People's Archive, can settle it, Hoagland notes.