By Eric Berman, REALTOR® | The Eric Berman Team at Compass
TL;DR:
Multi-family properties are valued on income rather than on comparable sales, which changes what a seller should do before listing. Buyers divide net operating income by a market capitalization rate — so improving documented income or reducing documented expenses raises the value by a multiple rather than by the dollar amount. Roughly, at a 6% cap rate, $500 a month of additional documented rent adds around $100,000 to value. That's the mechanism, and it's why undocumented income is worth nothing at the negotiating table. The other item that decides outcomes in Port Washington: whether the certificate of occupancy matches the number of units actually being rented.
How Buyers Actually Value the Property
This is the piece the standard advice leaves out, and it changes everything a seller does beforehand.
A single-family home is valued by comparison — what similar homes recently sold for. A multi-family property is valued primarily on what it earns. Buyers calculate net operating income: annual rental income less operating expenses, excluding mortgage payments. Then they divide that figure by a market capitalization rate to arrive at value.
The arithmetic has a consequence sellers rarely exploit. Because value equals income divided by a rate, every dollar of documented annual income adds a multiple of itself to the property's value. At a 6% cap rate, an additional $6,000 per year in documented rent adds roughly $100,000 in value — not $6,000.
That works in the other direction too. An expense that can be reduced or eliminated has the same multiplied effect.
Two qualifications that matter. Documented is doing real work in that sentence — a buyer's underwriter works from leases and tax returns, not from what the seller says the units could rent for. And market cap rates vary with property type, condition, location, and interest rates, so the multiplier isn't a fixed number.
The practical instruction: before listing, look at whether below-market rents can be brought closer to market within the constraints of existing leases and applicable law, and whether any operating expense is avoidable. Those changes are worth far more than cosmetic work.
The Documentation Buyers Actually Need
Given how valuation works, the file matters as much as the building.
Rent roll — every unit, current tenant, rent amount, lease start and end dates, and security deposit held. Leases for every occupied unit, including any amendments or side agreements. Two years of operating expenses, itemized: property taxes, insurance, utilities the owner pays, water and sewer, maintenance, snow removal, landscaping, and any management fee. Schedule E from the last two tax returns, which is what an underwriter will actually rely on. Capital improvement records — roof, boiler, electrical service, windows — with dates and costs. Vacancy history, honestly stated.
A complete file supports the asking price. An incomplete one invites the buyer to assume the worst and price accordingly, which is the same outcome as having lower income.
One caution worth stating: represent income accurately. Overstating rents in marketing material creates problems when the leases are produced during due diligence, and the correction happens with the seller's credibility already damaged.
Who Can Buy It — the Four-Unit Line
The number of units determines the buyer pool more than anything else about the property.
One to four units qualifies for residential financing. That means conventional mortgage products, potentially government-backed programs for an owner-occupant, and access to the entire pool of buyers who intend to live in one unit and rent the others. Owner-occupant buyers frequently pay more than investors, because they're buying a home rather than a return.
Five units and above is commercial. Different underwriting — the lender evaluates the property's income rather than primarily the borrower's — different terms, typically larger down payments, shorter amortization, and a much narrower buyer pool consisting almost entirely of investors.
For a Port Washington two- or three-family, this is favorable: the property competes for both investors and owner-occupants, which is the widest possible audience. Marketing should reach both, and they respond to different things. Investors want the numbers. Owner-occupants want to understand the living arrangement, the separation between units, and what their effective housing cost would be after rental income.
The Certificate of Occupancy Question
Here is the item most likely to derail a Port Washington multi-family sale, and it's specific to this property type.
The certificate of occupancy has to match the number of units actually being used. A property legally certified as a two-family but operating as a three-family — a converted basement, a finished attic apartment, a separate entrance added at some point — is a serious problem at sale.
The mechanics: after contracts are signed, the buyer's attorney orders municipal searches. The certificate on file states the legal use. If the property is being marketed and operated differently, that gap appears in writing. A lender will generally not finance a use the certificate doesn't support, the income from the unpermitted unit can't be counted toward valuation, and resolving it means either legalizing the unit or discontinuing its use.
Which office holds the record depends on the address. The peninsula spans several incorporated villages — Baxter Estates, Manorhaven, Flower Hill, Sands Point, and Port Washington North among them — plus unincorporated areas under the Town of North Hempstead, each with its own building department. The breakdown of which rules apply where sorts out the jurisdictions, and the full picture of how permit and certificate issues resolve covers what each costs.
Some jurisdictions also impose rental registration or permit requirements on multi-family properties. Whether one applies to a specific address is worth confirming with that village or town directly.
Do this before listing. A certificate mismatch discovered during due diligence, with income already represented in the marketing, is considerably worse than one addressed beforehand.
Tenants: What a Seller Actually Controls
The standard advice presents three options — sell occupied, deliver vacant, or a hybrid. The middle one requires correcting, because a seller frequently cannot deliver vacant at will.
The lease survives the sale. A buyer takes title subject to existing tenancies, at the same rents and terms, through the stated end dates. Closing changes nothing about them.
Ending a month-to-month tenancy requires statutory notice that scales with how long the tenant has occupied the unit — 30 days under one year, 60 days at one to two years, 90 days at two or more. Fixed-term leases run to their end dates and can't be shortened unilaterally.
Early vacancy requires negotiation. A written surrender agreement, drafted by an attorney, with consideration and a firm vacate date. Sometimes tenants accept readily; sometimes they don't, and a seller who has promised vacancy to a buyer without having secured it is exposed. The full treatment of selling with tenants in place covers notice requirements, showing access, and security deposit transfer.
Which approach maximizes value depends on the numbers. Strong tenants at market rents with documented payment histories are an asset to an investor and support the income-based valuation. Below-market rents with long-tenured tenants may actually reduce value to an investor while appealing to an owner-occupant who plans to live in one unit anyway.
The Tax Side Is Different Too
Selling an income property triggers considerations that don't apply to a primary residence, and they should be discussed with a CPA before a closing date is set.
Depreciation recapture. Depreciation claimed during ownership — or deemed claimed whether it was actually taken or not — is recaptured on sale, taxed federally at a maximum 25% rate on unrecaptured Section 1250 gain. For a property held twenty years, that's a substantial figure.
The primary-residence exclusion generally doesn't apply, or applies only partially where the owner occupied one unit. Allocation between the residential and rental portions is a CPA question.
A 1031 exchange is available. Unlike a primary residence, an investment property can be exchanged into another investment property to defer gain. It requires identifying replacement property within 45 days, closing within 180, and using a qualified intermediary — the seller cannot take receipt of proceeds at any point without disqualifying the exchange. That structure has to be arranged before closing, not after.
The broader treatment of how a sale is taxed covers the underlying mechanics.
A Worked Example
Consider a composite case — a Port Washington two-family near the Manorhaven line, both units occupied, held for eighteen years.
The upper unit rented at $2,100 against a market closer to $2,700; the lower at market. The owner's instinct was to spend $15,000 on cosmetic updates.
Running the valuation arithmetic redirected that. The upper unit's lease had four months remaining. Renewing at $2,600 added $6,000 in annual documented income, which at a 6% cap rate translated to roughly $100,000 in value — against zero cost. He waited the four months.
He also checked the certificate of occupancy, which certified two units. The basement had a kitchenette installed by a prior owner but wasn't being rented, so no mismatch existed. Confirming that before listing removed a question a buyer would otherwise have raised.
He assembled two years of Schedule E filings, both leases, an itemized expense summary, and capital improvement records for a 2019 roof and a 2021 boiler.
The property drew both investor interest and an owner-occupant buyer. The documentation supported the asking price rather than inviting discount, and the four-month wait was worth more than the renovation would have been.
Where to Start
Confirm the certificate of occupancy matches the units in use, and find out which village or town holds the record. Assemble the documentation file — rent roll, leases, two years of expenses and Schedule E, capital improvements, vacancy history. Look at whether below-market rents can move within the constraints of existing leases and applicable law, since income improvements are worth a multiple of themselves. Talk to a CPA about recapture and whether a 1031 exchange fits. Decide the tenant question honestly, understanding that vacancy requires negotiation rather than a decision.
Sellers wanting a starting read on value can begin with a quiet look at present figures, though an income property needs analysis beyond a standard estimate.
The Honest Bottom Line
Multi-family sells on numbers, and the numbers respond to different inputs than a single-family sale does. Paint helps at the margins. Documented income moves the value by a multiple.
The two things worth doing before anything else both cost little. Confirm the certificate of occupancy matches reality, because a mismatch discovered during due diligence is the most expensive surprise in this property type. And look hard at whether documented income can be improved before listing, because that arithmetic is more favorable than any renovation.
Sellers wanting to work through what a specific property supports, with no pressure attached, are welcome to start that conversation whenever it suits them.
This is general information, not legal, tax, or investment advice. Valuation methods, certificate of occupancy requirements, tenancy law, and tax treatment all turn on specific facts. Consult a licensed New York real estate attorney, a CPA, and the governing village or town about your circumstances.
FAQs
How is a multi-family home valued differently from a single-family?
Primarily on income rather than on comparable sales. Buyers calculate net operating income — annual rental income less operating expenses, excluding mortgage payments — and divide by a market capitalization rate to reach value. The practical consequence is that documented income improvements add a multiple of themselves: at a 6% cap rate, an additional $6,000 in annual documented rent adds roughly $100,000 in value. Documented is the operative word, since a buyer's underwriter works from leases and tax returns rather than from stated potential.
What documents do buyers want when selling a multi-family?
A rent roll listing every unit with tenant, rent, lease dates, and security deposit held. Leases for every occupied unit including amendments. Two years of itemized operating expenses covering taxes, insurance, utilities, water and sewer, maintenance, and any management fee. Schedule E from the last two tax returns, which is what underwriters rely on. Capital improvement records with dates and costs. And an honest vacancy history. A complete file supports the price; an incomplete one invites the buyer to assume the worst.
Does the certificate of occupancy matter for a multi-family sale?
It's the most consequential document in this property type. The certificate must match the number of units actually in use — a property certified as a two-family but operating as a three-family creates a serious problem. The buyer's attorney orders municipal searches after contracts are signed, and the gap appears in writing. Lenders generally won't finance a use the certificate doesn't support, and income from an unpermitted unit can't count toward valuation. Which office holds the record depends on which Port Washington village or town governs the address.
Can I deliver a multi-family property vacant at closing?
Not at will. The lease survives the sale — a buyer takes title subject to existing tenancies at the same rents and terms through their stated end dates. Ending a month-to-month tenancy requires statutory notice scaling with occupancy length: 30 days under one year, 60 days at one to two years, 90 days at two or more. Fixed-term leases run to their end dates. Early vacancy requires a negotiated written surrender agreement, and a seller who promises vacancy without having secured it is exposed.
What taxes apply when selling a multi-family property?
More than on a primary residence. Depreciation claimed during ownership — or deemed claimed whether taken or not — is recaptured on sale at a maximum federal rate of 25% on unrecaptured Section 1250 gain, which is substantial on a long-held property. The primary-residence exclusion generally doesn't apply, or applies only partially where the owner occupied a unit. A 1031 exchange is available to defer gain into another investment property, requiring identification within 45 days, closing within 180, and a qualified intermediary.
By Eric Berman, REALTOR® | The Eric Berman Team at Compass
Eric Berman | Long Island & Queens Associate Broker | Compass
1468 Northern Blvd, Manhasset, NY 11030
(917) 225-8596 | eric@ericbermanre.com | theericbermanteam.com
