Georgian brick townhomes of two to five stories on the 400 block of South Union Street, standing on ground excavated in 1989 as the site of Roberdeau's Wharf.
Harborside is one of the harder Old Town names to pin down on paper. It sits on the 400 block of South Union Street, a few blocks south of the foot of King, on ground Alexandria Archaeology excavated in 1989 as the site of Roberdeau's Wharf. It does not resolve cleanly in city records: the home count and the build years that circulate in listing copy did not trace back to a verifiable city source in August 2026. That shapes how you read every other number attached to this address, and it is why the documents come before the comparables here.
Brokerage listings describe roughly 63 townhomes here. The figure is worth having, but it comes from listing material, not a recorded plat, and the same caution applies to the construction dates quoted in marketing copy — neither was city-verified as of August 2026. That is not a reason to walk away; it is a reason to pull the governing instrument and the resale disclosure packet early, since those state the real unit count, the association's form and its charges. A search note too: Harborside names developments elsewhere in the Washington region, so anchor records and comparable sales on the 400 block of South Union Street, not on the name.
Before this ground held houses it held a wharf. Alexandria Archaeology excavated the Roberdeau's Wharf site here in 1989 — the same year Council adopted, on November 18, the Archaeological Protection Code that was folded into the zoning ordinance in 1992 and still puts city archaeologists in the path of ground-disturbing permits. That reaches owners, not only developers: a patio footing or a utility trench runs through the same review. It also separates this block from the neighbors it gets lumped in with: Ford's Landing sits over Keith's Wharf, site 44AX119; Robinson Landing yielded three 18th-century ship hulls and the 1854 Pioneer Mills site. Three adjacent addresses, three different wharves.
The houses are Georgian brick townhomes, and for a group this small the vertical range is notable: two to five stories. Floor plans, stair counts and usable space differ far more between two Harborside addresses than the shared name implies, so compare houses, not the community — and ask whether a given one has an elevator, where the mechanical equipment sits, and how the top floor is conditioned. Newer construction does not exempt the block from the Old and Historic Alexandria District. A Certificate of Appropriateness is required for exterior alterations visible from a public right of way, and a Permit to Demolish for removing or capsulating more than 25 square feet of material, seen or not. The 1993 design guidelines were being rewritten as of August 2026, with comment on the draft chapters closing September 2, 2026.
A block from the water, flood diligence outranks nearly everything else. Alexandria's current FEMA maps took effect January 11, 2024, and the mapped hazard area in Old Town reaches inland rather than stopping at the bulkhead; the city participates in FEMA's Community Rating System at Class 6, which it says earns up to a 20 percent premium discount. Nuisance high-tide flooding is a separate problem, arriving through the waterfront outfalls on clear days. The city's answer changed course in 2026: after the National Park Service denied the Waterfront Park pump station in February, Council voted June 13, 2026 to advance an enhanced gravity storm sewer alternative, including raising bulkhead and shoreline to elevation 6. The July 2026 test pits were dug north of here, on Union between King and Prince. Nothing was under construction as of August 2026; construction is targeted for summer or fall 2027. Get the elevation certificate and a bound flood quote before releasing a contingency.
Residential permit parking governs this street, so the first question is whether a specific house includes off-street parking — that answer changes the daily math more than any other feature. Permits are issued only to full-time residents of the district and priced per vehicle at $55 for the first, $75 for the second and $250 for each one after, and they do not override the citywide 72-hour rule. Alexandria City Public Schools runs one comprehensive high school, Alexandria City High School, on its King Street and Minnie Howard campuses. Surrounding southeast Old Town blocks, Ford's Landing among them, are zoned Lyles-Crouch Traditional Academy and George Washington Middle School for 2026-27, but assignment follows the address, not the neighborhood name — verify it in the ACPS Attendance Zone Locator. All current as of August 2026.
Harborside sits within Old Town Alexandria — that guide covers the zoning, permitting and site constraints that apply across the wider area.
Artur can confirm what applies to a specific address here — lot, zoning, association documents and school assignment — before you write an offer.
