---
title: "393 West End Avenue PH: Real Cost of a White Box"
description: "393 West End Avenue’s penthouse asks $13.9M unfinished. Review construction risk, terrace value, carrying costs and buyer protections."
url: "https://realestaterebatesnewyork.com/guides/393-west-end-avenue-penthouse-white-box-real-cost"
source: "Real Estate Rebate Team"
datePublished: "2026-07-29"
dateModified: "2026-09-03T18:44:12.509Z"
---

# 393 West End Avenue Penthouse Asks $13.9M Unfinished: What Is the Real Cost to the Buyer?

New Developments · By Régis Roumila · July 29, 2026

The full-floor Upper West Side penthouse offers 4,230 interior square feet and a 3,083-square-foot wraparound terrace, but its white-box delivery shifts construction cost, carrying time and execution risk to the purchaser.

![The rooftop penthouse addition and wraparound terrace at 393 West End Avenue. Listing image courtesy of Corcoran Group through RLS at REBNY.](https://realestaterebatesnewyork-bucket.nyc3.cdn.digitaloceanspaces.com/08daac8c-a5b8-4fc3-8cf2-2860e7c316c6.jpg)

*The rooftop penthouse addition and wraparound terrace at 393 West End Avenue. Listing image courtesy of Corcoran Group through RLS at REBNY.*

## The asking price is only the beginning

The Landmark Penthouse at 393 West End Avenue is asking $13.9 million for approximately 4,230 square feet of interior space and 3,083 square feet of wraparound terrace. It occupies the entire top floor and is being offered before interior completion.

That makes the advertised price only the first line of the buyer’s budget. The purchaser must also account for architecture, design, construction, professional fees, contingency, carrying costs and the time required before the residence can be occupied.

The penthouse’s greatest advantage is the ability to create a highly personalised home. That same flexibility is also the source of its largest financial and execution risks.

## The Landmark Penthouse at 393 West End Avenue

The active RLS listing is asking $13.9 million for a full-floor, five-bedroom penthouse with approximately 4,230 interior square feet and 3,083 square feet of private outdoor space. The residence may be purchased before interior completion or delivered through a sponsor-managed completion programme at a price available upon request.

- [393 West END Avenue #PH, New York, NY 10024 — $13,900,000, 5 bed, 5 bath](https://realestaterebatesnewyork.com/buy/newyorkcity/manhattan/10024/393-west-end-avenue-ph-PH-ny-10024)

### 393 West End Avenue penthouse at a glance

The residence combines a full-floor interior with an unusually large wraparound terrace, but the purchase price does not include a disclosed finished-interior package.

| Metric | Current information |
| --- | --- |
| Asking price | $13,900,000 |
| Interior space | Approximately 4,230 sq. ft. |
| Private terrace | Approximately 3,083 sq. ft. |
| Combined private space | Approximately 7,313 sq. ft. |
| Asking price per interior sq. ft. | Approximately $3,286 |
| Reported common charges | $8,202 per month |
| Interior delivery | Offered before interior completion; sponsor-finished price upon request |

**The buyer is evaluating a $13.9 million acquisition plus an undisclosed completion budget, professional fees, contingency and carrying costs.**

*Source: Current RLS listing RLS20102795 — Property taxes and the sponsor’s finished-delivery price are not stated in the Directus listing record and must be independently confirmed.*

## White-box freedom can mean transferred risk

Régis Roumila believes buyers should look beyond the language of customisation:

“Sponsors often believe that delivering a penthouse in white-box condition gives the buyer freedom, but in reality it usually transfers the construction cost, delays and execution risk from the sponsor to the purchaser.”

Even where permits or conceptual plans already exist, a luxury completion may require an architect, interior designer, contractor, expeditor, project manager and specialist consultants. During that period, the buyer may also be paying common charges, taxes, financing expenses, insurance and professional fees while the home remains unusable.

Change orders, material substitutions, coordination issues and construction delays can alter both the budget and the move-in date.

## One possible full-floor layout

![Floor plan for the full-floor penthouse at 393 West End Avenue showing interior rooms and wraparound terrace](https://realestaterebatesnewyork-bucket.nyc3.cdn.digitaloceanspaces.com/d6bc9bef-b920-4580-8fb5-6dbedfa32f96.jpg)

*Penthouse floor plan supplied with the active RLS listing. Buyers should verify approvals, dimensions and the current construction scope.*

The supplied floor plan shows five bedrooms, multiple entertaining areas and direct access to the wraparound terrace. Buyers should confirm which plans are approved, which are conceptual and what modifications remain possible under the offering plan, building rules, Department of Buildings requirements and historic-district controls.

### Buyer-managed completion versus sponsor-finished delivery

The two routes allocate design control, budget certainty and construction responsibility differently.

| Issue | Buyer manages completion | Sponsor delivers finished |
| --- | --- | --- |
| Design control | Highest control over layout, finishes and team | Controlled by negotiated plans, specifications and allowances |
| Budget certainty | Lower certainty; buyer absorbs changes and overruns | Potentially clearer if the contract fixes price and scope |
| Project management | Buyer coordinates architect, consultants and contractor | Sponsor or developer coordinates delivery |
| Delay risk | Primarily borne by buyer | Can be shifted partly to sponsor through deadlines and remedies |
| Warranty and defects | Split among contractors, vendors and designers | Potentially centralised if contract and warranties are clear |

**Sponsor-finished delivery may reduce coordination risk only when the contract clearly defines price, specifications, completion standards, deadlines and remedies.**

*Source: Buyer-advisory framework based on Régis Roumila’s professional perspective — This comparison is a negotiation framework, not a guarantee that either delivery method will be cheaper or faster.*

## Régis would keep a 15% to 20% contingency

Régis recommends that a purchaser maintain meaningful reserves above the initial construction estimate:

“I would recommend a contingency of at least 15% to 20% above the initial construction estimate, and possibly more for a highly customised luxury project.”

This is Régis’s professional planning framework, not a fixed industry rule. The appropriate reserve depends on how complete the plans are, the reliability of contractor pricing, imported materials, custom millwork, technology systems, terrace work and the degree of design change requested by the buyer.

A low initial bid is not necessarily the lowest final cost. The buyer should distinguish between a preliminary estimate, a detailed construction budget and a guaranteed or capped contract price.

## Calculate the total effective cost, not only the purchase price

A serious comparison with a finished Upper West Side penthouse should include every cost required to reach occupancy:

- Purchase price and closing costs

- Architectural and interior-design fees

- Engineering, expediting and permit costs

- General contractor and construction-management fees

- Kitchen, bathrooms, millwork, lighting and audiovisual systems

- Terrace landscaping, irrigation, furniture and permitted improvements

- Insurance and lender requirements during construction

- Common charges, property taxes and financing costs during the project

- Temporary housing or opportunity cost while the residence is unusable

- A contingency reserve for changes, delays and unforeseen conditions

The sponsor’s finished-delivery proposal should be compared against the same complete budget, not merely against the contractor’s base construction estimate.

## Why many luxury buyers prefer a finished residence

Régis notes that many buyers at this price level are senior executives, entrepreneurs or other professionals with limited time to manage a major renovation:

“With a white-box apartment, the buyer has no choice: they must undertake a full construction project before the residence is usable.”

A completed apartment gives the buyer the option to move in and change selected finishes later. A white-box residence requires decisions on nearly every visible and technical component before occupancy.

That does not make white-box delivery unsuitable for every buyer. It may appeal to someone with a trusted design team, a highly specific vision and the willingness to accept a longer, less predictable path to occupancy. The discount or negotiating terms should compensate for that burden.

## How should 3,083 square feet of terrace be valued?

The terrace is one of the penthouse’s defining features, but outdoor space should not be valued at the same price per square foot as conditioned interior space.

“I would generally begin by valuing it at approximately 20% to 30% of the interior price per square foot, with adjustments for views, privacy, access, layout and usability. Because the terrace is exceptionally large, the additional outdoor square footage should be valued at a lower marginal rate.”

This is Régis’s valuation framework, not a formal appraisal rule. A buyer should also investigate wind exposure, privacy, drainage, waterproofing responsibility, irrigation, landscaping restrictions, structural loading, terrace-door access and whether heaters, kitchens, pergolas or other improvements are permitted.

The 3,083-square-foot terrace equals approximately 73% of the reported interior area. Its value depends on how much of that space can be used comfortably and legally—not only its total measurement.

### Price per interior square foot comparison

The penthouse is asking a premium compared with selected completed sales in the same building. The difference reflects full-floor positioning, scale, terrace space and penthouse characteristics, while also excluding the cost of interior completion.

| Category | Price per interior square foot |
| --- | --- |
| Penthouse asking | $3,286 per sq. ft. |
| Unit 11A closed | $2,444 per sq. ft. |
| Unit 10A closed | $2,402 per sq. ft. |

**The penthouse asks approximately $840–$884 more per interior square foot than the selected 2025 closed sales before accounting for the cost of finishing the residence.**

*Source: Directus building-sales records and current RLS listing — The comparison is contextual only and is not a formal appraisal analysis. The penthouse figure represents an asking price, not a closed transaction.*

### How the penthouse asking price compares with selected closed sales in the building

Completed apartments in the same building provide useful context, but they are not direct penthouse comparables because they lack the same scale, full-floor privacy and outdoor space.

| Residence | Status | Price | Interior sq. ft. | Price per sq. ft. |
| --- | --- | --- | --- | --- |
| Penthouse | Current asking price | $13,900,000 | 4,230 | $3,286 |
| 11A | Closed January 2025 | $5,950,000 | 2,435 | $2,444 |
| 10A | Closed February 2025 | $5,850,000 | 2,435 | $2,402 |

**The penthouse asks materially more per interior square foot than the selected completed four-bedroom sales, reflecting its full-floor position, larger scale, views and terrace—but the buyer must still add the cost of interior completion.**

*Source: Directus building-sales records and current RLS listing — The closed sales are contextual references, not formal appraisal comparables. Duplicate historical feed records were excluded, and the penthouse figure is an asking price rather than a closed sale.*

## What should be negotiated with the sponsor?

Régis believes the cleaner outcome is a finished residence or a precisely defined completion package:

“Ideally, the sponsor should deliver the penthouse finished or offer a clearly defined completion package with an agreed budget, detailed specifications, a firm completion deadline, warranties, delay protections and an escrow holdback.”

The buyer’s attorney and construction advisers should consider:

- Approved plans and a detailed written scope of work

- Specified materials, appliances, fixtures and finish standards

- Allowances and who pays when selections exceed them

- Substitution rights and approval procedures

- A fixed or capped price where achievable

- Milestone dates and a final outside completion date

- Inspection rights and an objective completion standard

- Punch-list procedures and warranties

- Delay remedies and carrying-cost responsibility

- An escrow holdback until agreed completion obligations are satisfied

The exact protections will depend on the offering plan, purchase agreement and the sponsor’s willingness to negotiate.

## The correct comparison is finished cost versus finished cost

Régis summarises the buyer’s decision this way:

“The correct comparison is not simply the $13.9 million asking price. A buyer should compare the total effective cost of purchasing and completing the penthouse, including construction, professional fees, contingency, carrying costs and time, with the price of a finished penthouse at 393 West End Avenue or a comparable Upper West Side luxury condominium.”

The penthouse may ultimately deliver something difficult to reproduce: a full-floor home, four exposures, large-scale outdoor space and a personalised interior in a restored pre-war condominium.

But customisation has value only when the budget, timeline and contractual responsibility are understood. The purchase is not merely an apartment acquisition. It is also a development project.

## Sources and methodology

Current property details and images come from the RLS at REBNY listing for 393 West End Avenue Penthouse, represented by Douglas Brown Brown and the Noble Black team at Corcoran Group. Real Estate Rebate Team does not represent the seller.

Current listing: 393 West End Avenue Penthouse on Real Estate Rebates New York.

Same-building sales information comes from Directus building-sales records. Selected closed sales are used for context only and are not presented as formal appraisal comparables.

The 15% to 20% contingency range and the 20% to 30% initial terrace-valuation range are Régis Roumila’s professional frameworks. Actual construction costs, completion times and property values depend on plans, specifications, market conditions and professional analysis.

This article is independent buyer commentary, not an appraisal or legal, architectural, engineering, tax, financial or investment advice. Buyers should independently verify all figures and consult their attorney, architect, engineer, contractor, accountant, insurance adviser and lender.

---

**Have Questions Before You Buy?** Whether you are just starting your search or ready to make an offer, connect directly with Régis for high-level guidance, custom market reports, or to discuss the Buyer Commission Share.

[Schedule a consultation](https://realestaterebatesnewyork.com/contact)