| What it is |
Demolishing the existing building and constructing a new one from the ground up — the existing structure is removed and replaced entirely. |
Changing the building's primary use — most commonly office or hotel to residential — within the existing structure, using City of Yes and 467-m incentives. |
Upgrading and re-tenanting the building while keeping its existing use and structure — value comes from better operations, not a new building or new use. |
| Zoning requirements |
Must conform to current zoning or obtain a rezoning. As-of-right teardowns require only DOB permit review. Sites needing variance or rezoning add 12–18 months. |
City of Yes for Housing Opportunity (adopted December 2024) expanded as-of-right conversion eligibility to most buildings constructed before 1991, citywide. 467-m (FY2025 NY State budget) provides property tax exemptions for qualifying conversions with 25%+ affordable units. Note: 421-g expired in the late 1990s and is not available to any current project. |
Usually proceeds as-of-right because the use does not change. Landmark buildings require LPC approval for exterior changes. |
| Typical cost |
Highest — roughly $400–700/SF for new NYC construction plus demolition. |
Lower than ground-up — roughly $200–500/SF — but varies sharply with floor plate depth, window line, and plumbing. At 150 West 85th Street, buyers cited conversion feasibility as a primary reason for passing. |
Lowest — roughly $50–200/SF depending on scope. |
| Typical timeline |
Longest — roughly 3–5 years total including demolition plus a 2–4 year build. |
Medium — roughly 18–36 months — often faster than ground-up because the existing structure is reused. |
Shortest — roughly 6–18 months depending on scope. |
| What type of buyer pursues each |
Ground-up developers, institutional builders, and merchant builders with deep capital and patient timelines. |
Conversion specialists and residential developers using 467-m and City of Yes. At 150 West 85th Street, conversion/user bids ($18–20M) exceeded ground-up bids ($13–15M) by 20–35%. |
Value-add investors and owner-users seeking near-term income improvement. |
| When it applies to an owner |
A teardown maximizes value when the existing structure adds little, blocks a larger as-of-right building, and the lot's FAR is significantly underused. |
Conversion maximizes value when an obsolete commercial building has a structure and location suited to residential, the 467-m and City of Yes incentives apply, and the conversion premium over ground-up is real. |
Renovation maximizes value when the building's bones are good, modest capital unlocks higher rent, and the existing income value exceeds both land value and conversion value. |
| How it affects value or owner decisions |
A teardown realizes the lot's full buildable potential — the right path when the existing structure contributes little to value and FAR is significantly underused. |
A conversion repurposes an underperforming building into a higher-value use. At 150 W 85th, conversion bids ran 20–35% above ground-up bids. |
A renovation improves the income the existing building produces — the right path when modest capital reliably translates into higher rent. |
| Common misconception |
Some owners assume demolition is always wasteful — but an existing structure can be a liability worth removing when it blocks a far larger as-of-right building. |
Many owners assume any office building can be converted. Deep floor plates, limited light and air, and plumbing constraints make many infeasible. Strong candidates were built before 1991, have floor plates under ~10,000 SF, and windows on multiple sides. 421-g is sometimes cited — it expired in the late 1990s and is not available. The current program is 467-m. |
Some owners assume renovation is always the safer choice — but renovating a functionally obsolete building can sink capital into an asset the market will not reward at a higher rent. |
| Key question an owner should ask |
An owner should ask: "Is my existing structure worth more gone than kept, and does my lot's FAR support a significantly larger building?" |
An owner should ask: "Do my floor plates and window line make conversion feasible, and do 467-m and City of Yes apply to my building?" — see [Adaptive Reuse vs. Ground-Up Development]. |
An owner should ask: "Will capital expenditure actually raise rent and occupancy enough to pay for itself, and is this building more valuable as a development site?" |
| What the wrong choice costs |
Tearing down a conversion-eligible building forfeits 467-m incentives and the 20–35% premium conversion buyers pay over ground-up bids. |
Attempting conversion on a building with deep floor plates can strand hundreds of thousands in design and soft costs before the project is abandoned as infeasible. |
Renovating a building that is more valuable as a development site means improving an asset a developer will demolish — capital spent on renovation earns no return in that scenario. |
