Buying at The Harper.
Use the closing record, not the brochure.

The Harper is an operating, substantially sold Upper East Side condominium with three sponsor residences publicly available. That gives a buyer something early launches cannot: a real closing record, occupied-building observations and same-line evidence against which to test the remaining asks.

Building context

The Harper is at 310 East 86th Street between First and Second Avenues. IGI USA developed the project, ODA designed the architecture and interiors, and CORE handles sales. The official residence program emphasizes two- through four-bedroom homes, many with outdoor space; the amenity program includes an attended lobby, fitness center, children’s playroom, maker and music studios, screening and game rooms, rooftop lounges, a pet spa, bike room and optional storage.

Current sponsor availability and carrying costs

The official availability page displayed the three residences below on October 16, 2026. The monthly figures combine the published common charge and real-estate-tax estimate. Asking price per square foot uses interior area only; private outdoor space should be valued separately.

The public inventory page is a snapshot, not a complete Schedule A. Ask for a dated list of available, in-contract, closed, sponsor-retained and recently released homes, plus any storage being offered. Reconcile every tax and common-charge number with the current amendment and unit statement.

The closing record is the strongest value signal

Public closing records show active sponsor closings throughout 2026. Among the useful observations, 15C—also 2,650 square feet—closed at $6 million after a $6.25 million ask, or roughly $2,264 per square foot. Residence 11C now asks $5.975 million, almost the same nominal price and interior rate, so the buyer should isolate the floor, exposure, outdoor area, layout and closing-cost differences rather than rely on a building average.

For the smaller three-bedroom segment, 19C closed at approximately $4.134 million for 1,892 square feet, while 18A closed at $4 million for 1,813 square feet and 19A closed at $3.6 million for 1,636 square feet. Several reported closings were at or modestly below the last ask; that supports a real market while also showing that sponsor pricing was not uniformly nonnegotiable.

Those transactions are evidence, not automatic adjustments. Obtain the executed contract context available to the parties, confirm whether transfer taxes or other sponsor costs shifted to the buyer, and compare light, floor, balcony, exposure, finish and timing. A closing price can conceal credits or buyer-paid charges that change the net economic result.

Reconcile the legal project with the marketplace description

The New York Attorney General database identifies 310 East 86th Street Condominium under plan CD200176. The plan was accepted February 19, 2021 and became effective November 28, 2023. A July 2026 amendment increased the stated offering price to $260.509 million.

The Attorney General page is internally inconsistent on unit count: its building-information table shows 68 residential, three commercial and 24 storage units, while the first amendment says there are now 63 residential, three commercial and 24 storage units. Marketplace sources also use 63 residences. Counsel should establish the controlling current count from the plan, Schedule A, declaration and amendments, and confirm the purchased unit’s percentage interest, common-element allocation, voting rights and storage treatment.

• How does the 68-unit Attorney General summary table reconcile with the first amendment’s 63-unit statement?
• What did the latest Schedule A change about price, taxes, charges or status?
• What commercial units exist, how are expenses allocated, and what uses are permitted?
• Has a permanent certificate of occupancy been issued for the residence and relevant common areas?
• Which sponsor-control rights remain and when does owner control begin?

Move from projected operations to actual operations

The building is occupied and has a substantial closing history, so buyers should request more than a first-year sponsor budget. Review available financial statements, current budget, arrears, reserve balance, insurance, service contracts, staffing and any owner assessments. Compare actual costs with plan projections and identify subsidies or expenses that have not yet reached a normal run rate.

Specialized amenity rooms can be useful, but each has operating and replacement costs. Ask how programming for the maker and music studios is funded, what the rooftop kitchens require, whether storage is licensed or deeded, and how the retail condominium’s utilities, insurance and façade obligations interact with the residential condominium.

Price each remaining residence by its own attributes

For 20C, compare the $2,246 interior rate with recent 1,800- to 2,000-square-foot closings and quantify the value of its high floor and balcony. For 11C, start with the 15C closing and adjust for floor, view and 129-square-foot balcony. For Penthouse B, do not apply the $2,697 rate to 832 square feet of outdoor area; use a separate outdoor-value range based on privacy, access, configuration, exposure, utility and ongoing maintenance.

Then normalize buyer-paid costs. A sponsor contract may shift New York City and State transfer taxes, sponsor legal expense, working capital, superintendent residence contributions or other items. Compare net acquisition cost with nearby new development—including 255 East 77th Street, 200 East 75th Street and The 74—and with renovated Yorkville or Carnegie Hill resale.

Underwrite competition from inside and outside the building

A purchaser closing while sponsor inventory remains may compete with the sponsor at resale. The sponsor can control release timing, presentation and concessions, while an individual owner may have a different cost basis and urgency. Request the release strategy and identify any similar unlisted or retained homes before assuming three public listings represent all future supply.

The Harper’s durable arguments are modern layouts, substantial family-size inventory, outdoor space in many lines, amenity breadth and direct access to the Q train. Its resale test is whether a future buyer will pay the required premium for an 86th Street avenue-adjacent location when comparing established operations, actual taxes and newer product elsewhere on the Upper East Side.

Confirm buyer-broker compensation before contact

The official inquiry form asks whether a prospect is represented by a broker, and current RLS-syndicated sponsor listings carry offer-of-compensation language. The public pages reviewed on October 16 did not expose a numeric rate for 20C, 11C or Penthouse B. That supports broker participation but does not prove a percentage, duration, eligibility rule or who ultimately funds it.

Before the buyer or anyone acting for the buyer contacts the sales office, obtain written registration, procuring-cause and unit-specific compensation terms. Reconcile those terms with the buyer-representation agreement and state any possible buyer obligation. Compensation can change and should never be inferred from a prior closing or another residence.

Questions for CORE, management and buyer’s counsel

1. What is the dated status of every legal and marketed residence, including retained or released inventory?
2. How does the 68-unit Attorney General summary table reconcile with the 63-unit amendment and marketplace description?
3. Which closing is the sponsor’s best comparable for this residence, and what buyer-paid costs affected it?
4. What do current operations, reserves, insurance and arrears show versus the first-year budget?
5. Which punch-list, warranty, common-area or certificate items remain?
6. How are retail, storage, façade and shared-system costs allocated?
7. What written registration and compensation terms apply to this residence today?

Build a residence-specific decision file

For each finalist, record ask, proposed price, interior and outdoor value, common charges, current taxes, mansion tax, title and financing costs, sponsor-shifted expenses, storage and written credits. Attach the floor plan, current Schedule A, relevant amendments, comparable closings and the sales team’s written answers. The objective is one auditable net-cost and risk comparison.

The Harper buyer FAQs

What is currently available at The Harper?

The official page showed 20C at $4.25 million, 11C at $5.975 million and Penthouse B at $6.85 million on October 16, 2026. Confirm current status and request the complete dated inventory schedule.

Is The Harper a new-development condominium?

Yes. The Attorney General record identifies a new-construction condominium under plan CD200176, accepted in 2021 and effective in 2023.

Why does the Attorney General record show 63 and 68 residences?

The record’s building-information table shows 68 residential units, while the first amendment says there are now 63 and marketplace sources use 63. Counsel should identify the controlling current count; the guide does not assume the reason for the database conflict.

What is the best comparable for 11C?

Residence 15C is a useful same-size starting point: it closed at $6 million for 2,650 square feet. Adjust for floor, exposure, balcony, contract timing and complete buyer-paid costs.

Does the sponsor pay the buyer’s broker?

Current public listing language contemplates an offer of compensation, but no numeric unit-specific rate was public in the sources reviewed. Confirm registration, amount, eligibility and any buyer obligation in writing before contact.

What should be compared outside the building?

Compare active sponsor homes at 255 East 77th Street, 200 East 75th Street and The 74, plus renovated resale that solves the same bedroom, outdoor-space and monthly-cost need.

Availability, pricing, taxes, common charges, compensation and building status can change. Verify all facts in current sponsor materials, filed plans and amendments, written brokerage terms, unit tax records, financial statements and professional diligence.