--- 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" --- Real Estate Rebate Team Licensed Broker NY & NJ · License: 10491211335 ## 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 #### 393 West END Avenue #PH, New York, NY 10024 Price$13,900,000 Space5 beds, 5 baths NeighborhoodUpper West Side BoroughManhattan [View 393 West End Avenue Penthouse](https://realestaterebatesnewyork.com/buy/newyorkcity/manhattan/10024/393-west-end-avenue-ph-PH-ny-10024) Courtesy of Corcoran Group The Landmark Penthouse at 393 West End Avenue. Listing courtesy of Corcoran Group through RLS at REBNY. The buyer is evaluating a $13.9 million acquisition plus an undisclosed completion budget, professional fees, contingency and carrying costs. Key asking-price, size and carrying-cost information for the penthouse at 393 West End AvenueMetric Current information Asking price Current information$13,900,000 Interior space Current informationApproximately 4,230 sq. ft. Private terrace Current informationApproximately 3,083 sq. ft. Combined private space Current informationApproximately 7,313 sq. ft. Asking price per interior sq. ft. Current informationApproximately $3,286 Reported common charges Current information$8,202 per month Interior delivery Current informationOffered before interior completion; sponsor-finished price upon request The penthouse asks $13.9 million for about 4,230 interior square feet and 3,083 square feet of terrace, with reported common charges of $8,202 per month. The finished-interior price is not disclosed. ## 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 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. Sponsor-finished delivery may reduce coordination risk only when the contract clearly defines price, specifications, completion standards, deadlines and remedies. Comparison of buyer-managed construction and sponsor-finished delivery for the penthouse at 393 West End AvenueIssue Buyer manages completion Sponsor delivers finished Design control Buyer manages completionHighest control over layout, finishes and team Sponsor delivers finishedControlled by negotiated plans, specifications and allowances Budget certainty Buyer manages completionLower certainty; buyer absorbs changes and overruns Sponsor delivers finishedPotentially clearer if the contract fixes price and scope Project management Buyer manages completionBuyer coordinates architect, consultants and contractor Sponsor delivers finishedSponsor or developer coordinates delivery Delay risk Buyer manages completionPrimarily borne by buyer Sponsor delivers finishedCan be shifted partly to sponsor through deadlines and remedies Warranty and defects Buyer manages completionSplit among contractors, vendors and designers Sponsor delivers finishedPotentially centralised if contract and warranties are clear Buyer-managed completion offers more design control but places more budget and execution risk on the purchaser. Sponsor delivery may provide greater certainty only if the contract clearly fixes the scope, price and deadline. ## 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. 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. Bar chart comparing interior price per square foot: penthouse asking price at approximately $3,286, Unit 11A at $2,444 and Unit 10A at $2,402.Detailed structured table for the chart: Price per interior square foot comparisonCategoryPrice per interior square footPenthouse asking$3,286 per sq. ft.Unit 11A closed$2,444 per sq. ft.Unit 10A closedLatest$2,402 per sq. ft. 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. This table can be scrolled horizontally.Selected closed sales at 393 West End Avenue compared with the current penthouse asking priceResidence Status Price Interior sq. ft. Price per sq. ft. (Highlighted row) 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 about $3,286 per interior square foot. Units 11A and 10A closed in 2025 at approximately $2,444 and $2,402 per square foot respectively. ## 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](https://realestaterebatesnewyork.com/buy/newyorkcity/manhattan/10024/393-west-end-avenue-ph-PH-ny-10024). 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. Private Advisory • Régis Roumila ## Have Questions Before You Buy? 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