823 Classon Avenue (The Prospect)

The plan describes one building of seven floors and a cellar. The cellar holds the parking, reached by a ramp; one space at the base of the ramp is reserved for accessible parking. The ground floor is almost entirely the community-facility unit — about 4,154 square feet with 38 feet of street frontage and two entrances — around the residential lobby, elevator, stairs and the skylit recreation room.

The residential floors follow the plan's layout. On floors two and three, five apartments per floor, from about 490 to 1,100 square feet. The two larger lines on two and three, A and B, have terraces: 2A about 685 square feet, 2B about 250, and 3A and 3B reach private terraces by a stair one level down. Floors four through six carry four apartments each, 611 to 1,100 square feet, most with balconies of roughly 80 square feet. The seventh-floor duplexes each include a mezzanine level. The plan states the city prohibits using mezzanine space as a bedroom, and it lists the mezzanines at a 5-foot dropped ceiling. Price them as storage and flex space, not as bedrooms.

The plan also discloses lot-line windows in several second- through fourth-floor apartments, including 2A, 3A, 3B, 4A and 4B. They are inoperable and could be closed up at the owner's expense if the neighboring lot is built to their height. For those lines, the windows are light a buyer cannot count on permanently.

The Prospect is a small, professionally managed condominium with a single passenger elevator on DOB's device records. The façade has been through two inspection cycles: the Cycle 8 report, filed in 2019, rated it "safe with a repair and maintenance program," and the Cycle 9 report, filed in 2023, rated it safe. The DOB/ECB violations on record are resolved.

The community-facility unit is separately owned. DOB records a 2014 alteration, signed off in 2016, to occupy it as a day care center and day nursery. Under the offering plan the community-facility owner may seek certificate-of-occupancy and zoning changes and may subdivide the space without the board's consent, and must keep the space heated to protect the residential floors' pipes. The plan anticipated a separate commercial tax abatement for that unit, and the Department of Finance records carry a separate exemption on it.

The offering plan's special risks include the environmental history of the original building. A Phase I and Phase II assessment found leaking fuel-oil tanks in the old basement; the soils were excavated and the state Department of Environmental Conservation closed the matter. The same assessment found that former gasoline storage tanks had not significantly affected on-site soils but that it was unknown whether they had been properly closed. The plan summarizes this; buyers with concerns should read the full section and ask the board what, if anything, has been done since.

Recent sales

Recent closings at this building, from The Roebling Research Library. Prices are the transfer amounts recorded with the NYC Department of Finance; apartment-level detail is checked against the building’s own file in The Roebling Research Library before publishing.

Market read. Most recent trades (2026 to date) cleared a median $1,444/sf (floor-adjusted) across 2 sales. Floor-adjusted means each sale is restated to a constant mix of floors, so the figure can differ from the plain median of the sales listed above. Median listing discount 2.3% from the last ask — a recurring negotiation gap worth pricing into any offer or listing strategy.

Sales sourced from NYC Department of Finance recorded transfers (BBL 3-01178-7502; each condominium apartment is its own tax lot). Apartment-level facts (line, condition, asking-price context) curated and cross-verified in The Roebling Research Library. Not all transactions cross-verify with ACRIS records — sponsor and LLC purchases sometimes record at stipulated values rather than market price; square footage from recorded condo declarations and offering plans.

Underwrite the full tax bill. The exemption covers only 20 percent of the increase in assessed value this year and ends June 30, 2027. The 2027/28 bill is the one to plan around; ask for the unit's Notice of Property Value.

Know what the mezzanine is. On the seventh floor, the plan's mezzanine levels are not legal bedrooms.

Check for lot-line windows. If the unit is one of the lines the plan lists, assume those windows could be closed if the neighbor builds.

Read the community-facility terms. The ground-floor owner has rights to change use and subdivide without board consent. Understand how its share of the common charges and its use affect the residential floors.

Parking is for owners only. A space must be owned with a residential or community-facility unit. Confirm availability and the 12-versus-14 discrepancy between the roll and the plan.

Present the tax change up front. Buyers will ask about the 421-a. State that it ends in June 2027 and give the full-tax estimate; it removes the question.

Lead with outdoor space. The terraces on two and three and the seventh-floor roof terraces are the building's main distinction. Measure and photograph them.

Use the location the plan uses. The offering plan describes the building as one block from the Brooklyn Museum and the Botanic Garden.

If you're considering 823 Classon Avenue, also evaluate:

• 225 Eastern Parkway — The Traymore, the prewar condominium across Lincoln Place with frontage on Classon Avenue; the older-building alternative on the same corner
• 255 Eastern Parkway (The Woodrow Wilson) — prewar condominium conversion on the Parkway between Classon and Franklin
• 475 Sterling Place — 45-residence condominium two blocks north with deeded parking and a 25-year 421-a running into the 2030s; the tax contrast
• 488 Sterling Place — 25-residence, seven-story 2021 condominium with deeded parking and no 421-a; the closest match on scale
• 856 Washington Avenue — 26-unit 2017–18 condominium near Eastern Parkway; newer, similar size
• 892 Bergen Street — ten-story 2010 condominium between Classon and Franklin with a 25-year 421-a; the same vintage on a longer tax term
• 111 Montgomery Street — 163-unit 2018 condominium at the Botanic Garden edge; the large-building alternative