Subdividing a Brooklyn Warehouse: A Landlord's Framework for Turning One Vacant Floor Into Several Leased Units

A 24,000-square-foot warehouse floor sits empty in Sunset Park for nine months, and the owner's broker keeps bringing back the same conclusion: there is no single tenant out there who wants the whole thing. That conclusion is usually right, and it is usually where the conversation stops, because the next question — should I divide it into smaller units instead — sounds like a construction project, not a leasing decision. It is both, and treating it only as construction is how owners talk themselves out of the highest-return move available on an underleased industrial building.

The Question Division Actually Answers

Large-format industrial demand in the five boroughs has been shrinking for a decade, not because industrial activity is disappearing but because it has moved. Users who need 50,000 or 100,000 square feet under one roof — third-party logistics, big-box last-mile distribution — have largely relocated to purpose-built facilities in New Jersey, on Long Island, or in the outer reaches of the boroughs where clear heights, column spacing, and truck courts are built for that scale. What is left actively looking for space inside Brooklyn is a different tenant entirely: makers, contractors, food production, auto and trade services, last-mile delivery operators working out of smaller footprints, and self-storage-adjacent users who need 2,000 to 6,000 square feet, not 24,000.

Dividing a floor is not a renovation for its own sake. It is matching the building's product to the demand that is actually in the market this year, the same way an office owner re-prices a 4,000-square-foot floor as four 1,000-square-foot units. The question is not "can I divide this" — almost any industrial floor can be demised. The question is whether the revenue gain justifies the cost and the added management, and that only gets answered by running real numbers, not by instinct.

What Dividing a Warehouse Actually Costs

Industrial division carries costs an office conversion does not. Demising walls in a warehouse typically need to meet a fire-rated separation, which is a different (and pricier) build than a drywall partition in an office floor. Each new unit generally needs its own electric submeter, and older industrial buildings frequently need a service upgrade before submetering is even possible. Loading access is the hardest constraint: a floor with one curb cut and one dock door can serve one tenant's trucks without conflict, but two or three tenants sharing that same access need a scheduling agreement, a widened apron, or a second point of access — and if the building's certificate of occupancy classifies the space for single-tenant use, multiplying occupants can trigger a change-of-use filing with the Department of Buildings before a single new lease gets signed.

On a typical 24,000-square-foot Brooklyn warehouse floor being split into four 6,000-square-foot units, a realistic budget runs $35,000 to $55,000 per demising line for fire-rated separation, egress corridors, and individual electric service, plus $40,000 to $70,000 for loading-access improvements if the existing curb cut and apron cannot support multiple daily truck schedules without conflict. Before any owner commits to construction, I want a filed DOB pre-application or a zoning consultant's sign-off confirming the certificate of occupancy supports the new configuration, because discovering a CO problem after the walls are up is the single most expensive mistake I see on these projects.

The Revenue Case, Run Side by Side

Here is where division earns its cost. A single 24,000-square-foot tenant on that Sunset Park floor is realistically priced at $19 to $22 per square foot NNN in the current market — call it $20.50, or roughly $492,000 in annual base rent, and that number assumes the owner can even find one credit tenant willing to take the whole floor, which is the real bottleneck. Divided into four 6,000-square-foot units, the same floor targets the smaller-user segment that is actually transacting, at $27 to $32 per square foot — call it $29.50, or $177,000 per unit, $708,000 across all four.

That is a 44% increase in gross rent roll before subtracting construction costs, financed against demand that genuinely exists rather than demand the owner is waiting on. Against a combined demising and access budget of roughly $300,000 for all four units, the incremental $216,000 in annual rent pays that back in under a year and a half, even before accounting for the fact that four separate tenants diversify the owner's credit risk instead of concentrating it in one lease.

A vacant 24,000-square-foot floor is not a pricing problem waiting for the right broker. It is often a product the current market does not want built the way it is built.

The Risks Division Introduces That a Single Lease Doesn't

None of this is free of tradeoffs, and I tell owners the downside as plainly as the upside. Four tenants mean four lease negotiations, four renewal dates to track, and four relationships to manage instead of one — a meaningfully heavier operating lift for an owner without on-site management. Tenant mix matters more in a divided industrial building than almost anywhere else in commercial real estate: a metal fabricator running equipment at 7 a.m. and a food-production tenant needing a clean, low-vibration environment do not coexist well on the same floor, and getting that wrong shows up as complaints and early move-outs, not just an awkward pairing.

Financing is the other real constraint. Lenders underwriting industrial collateral often prefer the predictability of a single, long-term NNN lease to a credit tenant over a multi-tenant rent roll that looks, on paper, more like a mini self-storage operation than a stabilized industrial asset. That does not make division the wrong call — the revenue case above is usually strong enough to outweigh it — but it does mean an owner planning to refinance soon after completing the work should walk a lender through the plan before starting construction, not after.

When Division Doesn't Make Sense

Division is not the right answer on every vacant floor. A building with a single curb cut and no room to widen it, on a block where truck staging on the street is not realistic, often cannot support more than one or two tenants regardless of how the interior is demised. A deep, single-span floor plate with structural columns only at the perimeter can be expensive to demise into anything smaller than large sub-blocks, eroding the cost advantage that makes division work elsewhere. And a floor that already carries an existing tenant paying at or above market on a lease with several years left is usually better left alone; the math on breaking a performing lease to chase a divided-unit premium rarely clears the bar once broker costs, buildout, and lease-up risk on four new tenants are counted honestly.

I ran this same analysis for an owner of a 16,000-square-foot warehouse in East New York the year before the Sunset Park engagement, and the answer came back the opposite way. The building had a single curb cut shared with an adjacent property under an old easement, no room on the block to stage a second truck queue, and a floor plate with columns spaced tightly enough that anything smaller than three roughly equal bays would waste rentable area on structure and circulation. Three tenants at that size would have barely covered the demising and access cost within the lease term, and the owner still would have inherited the scheduling conflict the shared curb cut created. I recommended holding the building as a single-tenant listing, re-pricing it against current large-block comps instead, and it leased whole within four months. Running the numbers both ways, not assuming division is always the answer, is what makes the recommendation worth trusting either direction.

A Sunset Park Case Study

The floor described above was a real engagement. A 24,000-square-foot single-story warehouse bay in Sunset Park, part of a two-building industrial property, had sat vacant for eleven months after the prior tenant — a furniture wholesaler — relocated to New Jersey. The owner had two brokers run it as a single-tenant listing at $21 per square foot with no serious offers in eight months. I brought in a zoning consultant first, who confirmed the certificate of occupancy allowed multi-tenant industrial use without a change-of-use filing, which removed the biggest risk from the plan before any construction commitment.

I demised the floor into four 6,000-square-foot units, added a scheduled loading-dock system so each tenant had a two-hour daily window rather than open access, and marketed directly to the last-mile delivery and light-manufacturing tenants active in the submarket rather than waiting for a large single user. This is the analysis I run before recommending construction on any vacant industrial floor, not after the walls are already up. Three of the four units leased within four months at an average of $29 per square foot; the fourth leased two months later to a cabinet fabricator at $28. Combined annual rent came in at $702,000 against the $492,000 the single-tenant listing had failed to produce for nearly a year, against a construction cost of roughly $290,000 that the new leases paid back in nineteen months.

How I Run This Decision for an Owner

I start with the demand side, not the construction side: what size units are actually transacting in this submarket this year, at what rent, and how deep is that pool compared to the pool of tenants who want the whole floor. Only once that comparison shows a real revenue gap do I bring in a zoning consultant to confirm the certificate of occupancy supports the new configuration and a contractor to price demising, egress, and loading access on the specific floor plate, because a generic cost estimate is not good enough to make a six-figure decision on.

From there the math is straightforward: incremental rent against construction cost, a realistic lease-up timeline for four smaller units instead of one, and a plain conversation about the added management the owner is taking on. Division is not always the answer, but on a floor sized for demand that stopped showing up years ago, it is very often the only path back to full income — and it is a decision that pays for itself faster than most owners expect once someone runs the actual numbers instead of guessing at them.

Related reading: Bronx Warehouse Leasing: How to Structure NNN Terms and Grow NYC Building Income Without Paying a Broker. If you want this analysis run on your own building, that is what my fixed-fee reports cover.