What type of window is right for your NYC Home? A property-by-property guide

Are you a New Yorker looking to upgrade your windows? Walk into any window showroom in the country and a salesperson will show you double-hung windows. They'll talk about energy ratings and hardware finishes. They might even let you open and close a few.

But in New York City, that conversation is only 20 percent of what actually matters. The other 80 percent has to happen outside of the showroom and includes:

• Whether your co-op board will approve them
• Whether the Landmarks Preservation Commission needs to sign off
• Whether the profile will match the rest of your building's facade
• Whether the frame material can hold up to the specific stress your building puts on windows: steam heat, ambient vibration, or decades of urban grime

“The most common assumption clients get wrong is that because they own their dwelling, they can do whatever they want,” said Kyle Perdelwitz, general manager of Window & Door Pro, a New York City window and door installation company with more than 20 years of experience helping homeowners, co-op shareholders, and building managers navigate the city’s complex mix of board requirements, landmark regulations, and building codes. “While in a landmarked area, shareholders are subject to Landmarks Preservation Commission’s approval. Once approved by LPC, they will then need to get approval from their building as to what they are changing and if it conforms with LPC standards,” he said.

This guide breaks down what homeowners and co-op shareholders need to know about choosing windows by property type—because in NYC, where you live determines most of what's possible.

Before you choose: Know your constraints

Before anyone falls in love with a window, there's a more practical question to answer: Who actually controls what goes in your building?

In a co-op, the answer is usually the board. Most co-ops require prior approval for any window replacement—and many have already designated approved manufacturers or styles to maintain a uniform facade. Showing up with a window your board hasn't pre-approved is a reliable way to delay your project by months.

In a condo, you typically own your unit outright, but the building's common areas (including the exterior facade and window openings) are shared. Replacement still often requires board or management sign-off.

For brownstone owners, the key question is whether your property sits in an NYC historic district or is individually landmarked. If it is, the Landmarks Preservation Commission (LPC) has authority over any change to the exterior appearance—including windows. That doesn't mean you can't replace them; it means the replacement needs to match the historic character of the building in profile, material, and operation.

For most window replacements that involve structural changes, a Department of Buildings (DOB) permit is required. An experienced installer will handle this, but it's worth knowing upfront that it's part of the timeline.

Bottom line: Start with your building's rules, not the product catalog. The fastest path to the right window is understanding your constraints before you start shopping.

Caption

Window & Door Pro brought new windows to this stately Gramercy Park prewar, successfully matching the building's classic limestone facade and meeting co-op board standards.

Credit

Window & Door Pro

Prewar co-ops and condos

Best for: Wood-clad or high-quality aluminum, double-hung or casement, with attention to profile matching and sound performance

Prewar buildings—those built roughly between 1900 and 1940—are the backbone of New York City's residential real estate. They're also among the most complicated buildings to work with when replacing windows, because the original architecture sets expectations that modern replacement products often can't meet.

The characteristic double-hung windows of a prewar building have a specific look: narrow profiles, divided lights, and a scale that's proportional to the building's facade. Many co-op boards that have standardized window specifications did so precisely to protect that look, preventing the patchwork effect that happens when different products are installed over time.

“The most common acceptable LPC-approved brands for wood/clad would be Marvin on the more streamlined produced and Parrett on the higher-end custom side,” Perdelwitz said. “There are a multitude of other manufacturers that are acceptable but those two lead the race.” 

For all-aluminum applications, Window & Door Pro favors Universal Windows—an energy-efficient manufacturer available in short runs with no minimums, which gives both the installer and the client flexibility without locking into a large vendor commitment.

Beyond aesthetics, prewar buildings have a specific set of performance demands. Steam heat—still common in older NYC buildings—creates significant interior humidity swings throughout the heating season, which can stress window seals and frames over time. Sound is another major factor: prewar buildings in dense neighborhoods face constant noise from traffic, buses, and street activity. Glazing specifications matter here, and a good installer will match the glass package to the exposure.
For most prewar co-ops and condos, wood-clad windows—where a natural wood interior meets a durable aluminum or fiberglass exterior—are the standard recommendation. The wood interior maintains the warmth and visual quality of the original, while the exterior cladding holds up to weather and urban pollution. Marvin, Pella, and Kolbe are among the manufacturers whose products regularly meet both aesthetic and performance requirements in this context.

Watch for: Co-ops that require a specific manufacturer will often tell you this upfront—but always confirm with the managing agent before specifying any product.

Postwar High-Rises

Best for: High-performance aluminum, thermally broken systems, building-wide coordination

Postwar buildings—the towers and mid-rises constructed from the late 1940s through the 1970s— present a different set of challenges. These buildings were designed with aluminum windows, and aluminum is almost always the right replacement material here. But not all aluminum is equal, and the performance gap between a low-cost aluminum unit and a high-quality thermally broken system is enormous.

"Thermal break" refers to a layer of insulating material built into the aluminum frame that prevents the cold outside from transferring directly through the frame into your apartment. In a drafty postwar tower, the windows are often the single biggest source of heat loss—and of the condensation and mold that follows.

High-rises also come with wind load considerations that simply don't apply at street level. A window on the 30th floor of a Midtown building experiences dramatically different pressure than the same unit installed in a brownstone. Products need to be rated and installed accordingly.

“We often engage in window programs with co-op boards and building management companies,” Perdelwitz said. “We look to streamline offerings and keep shareholders together in the multiple steps in the process. We try to bundle multiple apartments together to leverage the best bulk pricing with our vendors and maximize ancillary requirements.”

One important dynamic in postwar high-rises: building-wide window replacements—where the board coordinates replacing all windows across the building at once—are far more common here than in prewar buildings. If your building is considering this, it's worth understanding how the process works, what the board's approval rights are over individual apartments, and what options you have if you've already replaced your own windows. (Yes, this situation comes up—and it's more complicated than it sounds.)

Brownstones and Townhomes

Best for: Wood or wood-clad on the facade, steel where LPC-approved, great opportunity on the rear of the building
No property type generates more window conversations in New York City than the brownstone. And no property type has more variables.

Brownstones and rowhouses are often located in or adjacent to historic districts—neighborhoods like Brooklyn Heights, Cobble Hill, Park Slope, Harlem's Strivers' Row, and the Upper West Side's Riverside Drive. If your brownstone sits in a historic district, the LPC has authority over any changes to the exterior, including windows.

What the LPC looks for is straightforward, even if navigating their approval process isn't: the replacement windows need to match the original in profile (the physical dimensions and proportions of the frame), sight lines (the visible lines of the frame when looking at the building), glass-to-frame ratio, and operability (how the window opens and closes). They're not requiring that you use the same material—they're requiring that it look the same from the street.

For most brownstone facades, wood or wood-clad windows are the strongest choice—both because they best replicate the original appearance and because they perform well in this building type's specific conditions (older plaster walls, varying humidity, less uniform openings than modern construction).

For buildings where steel windows were original—particularly in loft-style buildings and some prewar construction—steel remains the gold standard, and often the only option LPC will approve. Manufacturers like Hope's Windows specialize in historically appropriate steel systems that are built for this precise use case.

“Customers have different options for their secondary facades vs their primary,” Perdelwitz said. “Each has their own set of rules and standards they need to keep to. For example, you can alter an opening on a non-visible facade, but where it’s visible from the street or to the public, you will have no options but to keep to original size and design.” 

One often-overlooked opportunity in brownstone renovations: the rear of the building. Many historic district rules apply primarily to what's visible from the street—meaning the rear garden wall may have significantly more flexibility than the front facade. This is where folding glass walls, larger openings, and more contemporary glazing systems can often be incorporated, bringing light and indoor-outdoor connection to a space that's traditionally underutilized.

New Construction and full gut renovations

Best for: Aluminum systems, specialty folding and multi-slide doors, architect-specified products
New construction and full gut renovations are a different world from replacement work. There are no existing windows to match, no board-imposed limitations on previously approved products, and—in many cases—an architect already involved with strong preferences about what goes in.

Aluminum dominates new construction for practical reasons: it's dimensionally consistent, performs well across a range of conditions, requires minimal maintenance, and can meet NYC's increasingly stringent energy code requirements when specified correctly. Curtain wall systems and storefront-style glazing, once the domain of commercial projects, have become common in residential new development as well.

The other product category that comes up frequently in new construction and high-end renovations is specialty door systems—NanaWall folding walls, multi-slide door systems, and large-format glass that creates the seamless indoor-outdoor connection that's become a hallmark of contemporary NYC renovation projects. These are statement-making installations that require precise structural coordination, and they're not inexpensive. But for a garden-level brownstone kitchen, a rooftop penthouse, or a full rear addition, they can transform how a space feels.

If you're buying into a new development, it's worth asking specifically about window specifications before closing—the brand, the glazing package, the warranty, and who handles service. Window quality varies dramatically across new development projects, and it's rarely prominently disclosed.

Caption

Window & Door Pro restored the windows on this ornate Victorian-era building, matching the original arched profiles and sage green frames to preserve the historic character the building's architecture demands.

Credit

Window & Door Pro

Landmarked buildings and historic districts

Applies to: Any property type that is individually landmarked or sits within one of NYC's 150+ historic districts

Landmark designation deserves its own section because it changes the calculus for any property type—co-op, condo, or brownstone. There are more than 150 historic districts and over 36,000 individually landmarked properties in New York City. If your building falls into either category, your window replacement options are shaped significantly by LPC requirements, and navigating them requires an installer who has done it before.

The good news: the LPC process, while time-consuming, is navigable with the right preparation. What the commission is trying to preserve is the visual character of the building – not prevent you from replacing aging or failing windows. An experienced window specialist can tell you upfront what's likely to be approved, what documentation you'll need, and what the realistic timeline looks like.

For most landmark work, finding a manufacturer with LPC experience is as important as finding the right product. A company that has never submitted drawings to the commission will create delays that an experienced team won't.

The Bottom Line

Choosing windows in New York City is not a product decision—it's a building decision. The right window is the one that fits your property type, meets your regulatory environment, and delivers the performance your specific building demands. That combination is different for nearly every project.

Window & Door Pro has spent more than 20 years working across all of these building types, from LPC submissions in Cobble Hill to high-rise replacements in Midtown to new construction in Long Island City. Their approach starts with understanding your building before recommending any product.

If you're planning a window or door project and aren't sure where to start, the best first step is a conversation with someone who knows the full landscape—approvals, products, and installation.