Issue 105 – Combining Apartments for Greater Resale Value — When 1+1=3

Who hasn’t dreamed of having an extra room in their home? For some, that dream can become a reality by strategically buying two units and combining them into a larger living space.

This approach particularly appeals to the many people who love their current building and apartment. Buying a connecting unit — to either side, above, or below — can be incredibly beneficial because the owners can remain in their beloved residence while expanding their square footage. It allows them to capitalize on the place they’ve called home in creating a more expansive footprint.

Just imagine: Buying an adjoining unit means not having to change your commute or leave your memories behind. Your very identity might well be engrained in the dwelling. It also means avoiding the hassle of searching for another place to buy, dealing with the timing of selling an apartment to buy a bigger one elsewhere, and (importantly) enduring another stressful board interview! Adding onto your apartment is the most seamless way to increase precious living space with minimal disruption and change.

Of course, the above assumes a connecting unit is or will become available. Another, likely easier, option is to buy two units together in a new development in the preconstruction stage. This way, you can view the floorplans before the build-out has begun and discuss how best to combine the units with the developer. Namely, you can make the finishes consistent throughout, and the developer can ensure the plumbing and gas lines are efficiently integrated.

Whichever way you go about combining two units, there are a few significant drawbacks to keep in mind. A primary concern should be whether the size of the combined space will have enough value to justify this endeavor. You want to be sure the value is both immediate and increases over time so you can get a solid ROI when it is time to sell, even if that won’t happen for a decade.

For example, combining units might deprive the space of two highly desirable qualities: abundant natural light and impressive views. Or it might result in an awkward layout (more on this below). This value assessment can be complex when you hope to remain in your preferred building, but a place on, say, the third floor that doesn’t hold value would not be prudent.

Large entertaining and living spaces with sizable bedrooms that feel comfortable garner the most value. Specific examples include a great room with 13 to 28 feet of frontage, a luxurious primary bedroom with dual bathrooms, and a chef’s kitchen that becomes the heart of the home. The ultimate win? Integrating two corner units with panoramic views.

Other factors to consider before embarking on this endeavor include financing, building and city regulations, demolition and construction costs, and tax liabilities. You should also assess whether a precedent exists in your building, especially if it is a co-op. If not, doing a combination can be challenging and frustrating, causing much stress and expense. Because of “wet-over-dry” rules, you might be unable to add a bathroom or move the kitchen where you want. In addition, buildings may say that they will allow something only to reverse course after you’ve purchased the second unit.

An essential preliminary step is consulting with an architect and developing a firm plan. Do you want to add a smaller unit to an existing large one? According to a recent article in Brick Underground, duplexing up or down might prove more difficult because it involves building a new staircase requiring structural changes. Many boards will not approve this large-scale work.

You should avoid ending up with a Frankenstein apartment, meaning one that is put together haphazardly with no natural flow. A big no-no is a random hallway or weird entry that doesn’t fit into the fuller space. Ditto an apartment that feels like a maze, where you can’t tell which way to go.

Another potential pitfall is that unless you file with the city as a single-family residence, meaning just one permit for the entire space, the carrying cost can be slightly higher than you’d prefer because you are incorporating an additional unit into your original space.

Finally, although it is wonderful to avoid the general upheaval of moving, the labor and construction fees can be exorbitant, notably if you have updated your present apartment and the add-on unit may have done some renovations along the way. Labor fees can really become a factor if the condition of the apartment is not on the same level. It can be even more expensive if the combination requires plumbing upgrades and matching the flooring and finishers, some of which may have been discontinued. It gets even more complicated when you must file plans with the DOB and deal with your building’s architectural requirements, such as knocking down support walls or creating a duplex.

The ultimate advice is to do your due diligence. Always and proactively read the alteration agreement with a fine-tooth comb, looking for rules that would preclude completing your combination. Find out ahead of time if the building is supportive of this type of change. Ask any neighbors who have undergone this kind of renovation.

One additional note: Depending on the scope of work, you may have to move into a short-term rental and put items into storage, or at least have limited use of your everyday space, for a period.

The overarching goal is cohesion throughout, making every area as functional and aesthetically pleasing as possible. The rooms should be right-sized and have a clear purpose—is it a bedroom or a study? They also need to be carefully organized, or your home will feel discombobulated.

The bottom line is that combining two — or even three! — units can be a massive boon for anyone interested in increasing living space and resale value if they know what to look out for and what to avoid. This single step can create an architectural masterpiece and a genuinely unique home.

Issue 127 – The Price Isn’t the Price

A new calculation is changing what a New York apartment is actually worth. For decades, NYC real estate has been obsessed with price per square foot. However, now we may be entering the era of cost per year.

Consider two apartments of the same size, price, amenities, light, view, and location. If one has $6,000 in carrying costs and the other $11,000, are they really worth the same amount?

Increasingly, I would argue they are not because buyers aren’t simply purchasing apartments anymore. They are purchasing the economics of the buildings they’re in, which are starting to matter enormously. Think: insurance, labor, utilities, repairs, taxes, assessments, energy compliance, staffing, capital improvements, and reserves. While monumentally important, none of these photograph well, but all determine whether an apartment is easy to own — and eventually sell.

We have always understood that certain characteristics affect value: a lower floor trades differently from a higher one, an awkward layout matters, a protected view commands a premium, and poor light equals a discount. However, I contend another discount is related to the aforementioned carrying costs.

The sexiest amenity in New York real estate may soon be a healthy balance sheet. That sounds less exciting than a lap pool, unless you are the one writing the checks. Operating costs in New York have been rising, putting pressure on building budgets and making previously deferred capital projects harder to ignore.

The 2026 New York City Price Index of Operating Costs — which tracks expenses for the city’s rent-stabilized building stock — illustrates the broader pressure. Over the five years through 2026, insurance costs in that index increased more than 80%. Maintenance increased 29%, utilities more than 26%, administrative costs more than 21%, and labor nearly 16%.

Those figures aren’t a direct proxy for every condominium or cooperative in Manhattan. But they illustrate something anyone involved in operating New York buildings already understands: buildings are getting more expensive to run.

One mistake buyers can make is falling in love with the apartment and treating the building as secondary. In New York, you aren’t just buying four walls; you’re buying into a small economy. You’re inheriting its management decisions, staffing structure, physical plant, reserve philosophy, insurance exposure, and capital planning.

A building that deferred maintenance may appear inexpensive today because it hasn’t yet charged owners for the work it needs. That doesn’t necessarily make it inexpensive. It may mean the bill hasn’t arrived yet. Conversely, a building that recently completed an expensive façade project, replaced major mechanical systems, or invested in energy efficiency may initially appear less attractive because owners have already absorbed those costs. We need to consider which building presents the greater risk over the next decade. The answer isn’t always obvious from the monthly maintenance number.

Buyers understandably love low carrying costs, and brokers value them because they make a property easy to market. But low monthly charges deserve as much scrutiny as high ones. A good broker asks: Why are they low? Is the building extraordinarily well managed? Does it have other income? Are the reserves substantial? Or has the board resisted increasing common charges while postponing expensive work?

An important distinction exists between efficient and underfunded. A well-run building with appropriately funded reserves may ultimately be far more economical than one with artificially low monthly charges followed by recurring assessments. It’s not just the number that is meaningful, but the story behind it.

Few words cause more anxiety in a New York transaction than “assessment.” Even here, context matters because not every assessment is a red flag. An assessment financing a necessary capital improvement can actually strengthen the building. A new roof, elevators, façade work, upgraded mechanical systems, or energy improvements may protect long-term value.

The more important questions a sales pro considers are: What is the assessment for? Why didn’t reserves cover the expense? Is it part of a thoughtful capital plan or the latest in a recurring series of emergencies? And, perhaps most importantly, what comes next? A $500 monthly assessment with a clear end date concerns me considerably less than a building with no assessment, minimal reserves, and several million dollars of foreseeable work.

New York’s environmental requirements add another layer of complexity. Local Law 97 places emissions limits on many large buildings and creates increasingly stringent requirements over time. The encouraging news is that the overwhelming majority of covered privately-owned buildings are currently meeting the applicable limits.

But buyers should still understand what their particular building is facing; Has the Board commissioned the appropriate studies? What capital improvements may eventually be required? Has money been allocated? Is compliance incorporated into long-term planning? The concern isn’t whether a building faces a penalty today; it’s whether the building has a credible plan for tomorrow. That, increasingly, is part of due diligence.

New development creates its own version of this problem. Buyers are understandably attracted to pristine buildings with spectacular amenities and, sometimes, surprisingly reasonable initial common charges, but what will the building actually cost to operate when it is fully functioning?

Pools, spas, private dining rooms, screening rooms, landscaped terraces, playrooms, fitness centers, and mechanical systems all require staff, maintenance, and money long after the sales office closes.

The glossy brochure tells you what you’re getting. The budget tells you what you’re buying — both matter.

This conversation also requires nuance when comparing co-ops and condos. A co-op’s maintenance can initially look dramatically higher because it often incorporates expenses that a condo owner pays separately, including the shareholder’s proportionate share of the building’s real estate taxes. A condo may show a lower common-charge number while property taxes sit alongside it.

So, comparing maintenance to common charges without understanding what each includes is meaningless. The correct question isn’t: Which monthly number is lower? It is: What is my total cost of ownership, and what am I receiving in return? I believe strong building economics will increasingly become an amenity in their own right.

Brokers spend an immense amount of time learning how to talk about marble, appliances, ceiling heights, views, and finishes. We should be equally capable of explaining the financial health of the building we’re selling, because that is a big part of valuation.

None of this means price per square foot is irrelevant. It’s still an important metric. But like any metric, it becomes dangerous when used without context.

I’ve spent my career watching New York buyers pay premiums for things that cannot easily be replicated, including light, views, ceiling height, architecture, location, outdoor space, great proportions. But I always add another thing to the list: financial soundness. That may not command the same emotional response when someone walks through the front door. But increasingly, it may command something just as valuable – confidence, which matters in uncertain markets.

For years, we’ve asked buyers how much apartment they can afford. Now we need to start asking them how much building they can afford.  Because in New York, you don’t just buy the apartment — you inherit the economics beneath it.

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