Combined Unit Sales - Decombination Risk and Legal Reversal Requirements

Overview

Combined units - apartments created by merging two or more adjacent units - present unique challenges for sellers. If the combination was performed with proper building and DOB approvals, the combined unit can be sold as a single apartment with an updated certificate of occupancy. If the combination was performed without proper permits (a common scenario in older NYC buildings), the seller faces the risk that the buyer's attorney or lender will require legal separation back to the original configuration. This decombination risk can derail transactions, reduce the buyer pool, and force costly remediation.

Key Strategy

Verify legal status completely before listing. If the combination is properly documented, market the unit as a single apartment with full documentation available to buyers' attorneys from day one - this eliminates due diligence delays. If the combination is unpermitted, evaluate the cost and timeline of retroactive legalization versus selling at a discount that reflects the buyer's remediation cost. In many cases, investing in retroactive permits before listing produces a better net outcome than absorbing a buyer's discount demand.

What To Do

Before listing, verify four critical items: (1) DOB approved the combination with appropriate permits, (2) the co-op or condo board approved the alteration, (3) the certificate of occupancy was amended to reflect the combined configuration, and (4) the tax lot (for condos) or share allocation (for co-ops) was adjusted. If any approval is missing, obtain cost estimates for retroactive legalization. Have your attorney prepare a documentation package showing the legal status - make this available to buyer's counsel immediately upon request. If the combination is unpermitted, disclose this upfront and price accordingly rather than risking a deal collapse during due diligence.

Common Mistakes

Listing a combined unit without verifying its legal status, leading to mid-transaction discoveries that kill deals. Assuming the combination is legal because the building allowed it years ago - board verbal approval without a written alteration agreement is insufficient. Failing to update the certificate of occupancy even when DOB permits were obtained. Not disclosing the unpermitted status, which surfaces during the buyer's title search and creates adversarial negotiations.

Frequently Asked Questions

What is decombination risk when selling a combined apartment?

If your combined apartment was merged without proper DOB permits or board approval, the buyer's attorney or lender may require legal separation back to the original configuration - or refuse to proceed entirely. Before listing, verify DOB permits, board alteration agreements, certificate of occupancy amendments, and updated share allocations or tax lots. Missing any of these can severely narrow your buyer pool.

What happens if I combined two apartments and want to sell?

If your combination was done without proper board and DOB approval, you may need to legally reverse it before selling - which can cost tens of thousands of dollars and delay your sale by months. Even properly approved combinations can complicate sales because the buyer's lender and managing agent must confirm the legal status. Get a certificate of occupancy review and board documentation before listing.

Should I legalize my unpermitted combination before listing?

In most cases, yes - retroactive legalization before listing produces a better net outcome than absorbing the buyer's discount demand. Buyers pricing in decombination risk typically over-discount by 20-40% more than the actual legalization cost. Get estimates from an architect and expediter for DOB permits, then compare that cost against the expected price reduction if you sell as-is with disclosed permit issues.

Can a buyer's lender refuse to finance a combined apartment?

Yes - lenders require clear legal status before funding. If the certificate of occupancy does not match the current configuration, or if the combination lacks DOB sign-off, most lenders will decline to fund the loan. This restricts your buyer pool to all-cash purchasers, significantly reducing competition and likely producing a lower sale price. Resolving the legal status before listing opens financing to all buyer types.

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This article provides general educational information only. It is not legal, tax, financial, insurance, compliance, housing, brokerage, or professional advice. Rules, tax rates, obligations, enforcement practices, and market conditions vary by property, building, contract, municipality, and jurisdiction, and they change. Sellers should consult a qualified attorney, CPA, or other appropriate professional before making decisions based on their specific situation.