How are window treatments different for prewar vs new construction apartments in NYC?

Prewar and new construction apartments in NYC present completely different challenges and opportunities for window treatments—and treating them the same way is a rookie mistake. Prewar buildings (pre-1940) have irregular window openings, deep frames, and plaster walls. New construction has standard dimensions, drywall, and often floor-to-ceiling glass. These differences change everything about what you can install, how you install it, and what will actually look right.

Window opening size and irregularity

Prewar apartments—especially in neighborhoods like the Upper West Side, Brooklyn Heights, and the Upper East Side—were built with hand-finished openings. You'll find windows that are off-square, frames that vary by half an inch from top to bottom, and sills at different heights in the same room. We recently completed a Central Park West prewar where three windows in one wall had three different depths and widths. New construction in Long Island City, DUMBO, or Williamsburg? The openings are spec'd to the millimeter. Standard sizes mean you can order some treatments off-the-shelf; prewar almost always requires custom sizing.

This matters because Roman shades, motorized Somfy shades, and drapery all need precise measurements. In a prewar, we're often building out to make the treatment fit the space elegantly rather than fitting the opening exactly. In new construction, we're working within predictable parameters.

From our experience: prewar windows in a 1920s Park Avenue building may have working sash weights and rope systems behind the frames—you can't just drill into those walls.

— Glamour Decorating, from 30 years of NYC installs

Wall construction and installation anchoring

This is the biggest technical difference. Prewar buildings have plaster walls—thick, hard, sometimes horsehair-reinforced plaster over wood lath. New construction has drywall over metal studs. When we install a motorized shade or heavy drapery rod in a prewar, we're anchoring into plaster and hunting for the wooden studs behind it. In new construction, studs are 16 inches on center, predictable, and the walls are soft.

For a motorized Somfy shade in a prewar, we need heavy-duty toggle bolts or lag bolts into studs. In new construction, we use standard studs and anchors. The cost difference is real—prewar installation often takes 20–30% longer because we're drilling carefully, using a stud finder, and working around the unexpected (pipes, electrical that wasn't marked, deteriorated plaster). We've installed hundreds of custom drapery rods across Manhattan; prewar apartments consistently require reinforcement we wouldn't need on the other side of a new construction building.

From our experience: a prewar renovation in Brooklyn Heights once revealed lead paint on the window frames—we had to adjust our installation sequence entirely.

— Glamour Decorating, from 30 years of NYC installs

Ceiling height and proportions

Prewar buildings often have higher ceilings—9 to 12 feet is standard in many classics. New construction is typically 9 feet (sometimes 8 feet 6 inches in less expensive builds). Higher ceilings in prewar apartments mean more dramatic window treatments are possible and actually necessary. A 6-foot-tall drapery panel looks proportional in a prewar with 11-foot ceilings; in a new construction with 9-foot ceilings, it can overwhelm the room.

This affects design recommendations directly. In prewar Hamptons estates, we often recommend floor-to-ceiling drapery with motorized shades layered underneath. In new Long Island City construction, we're more thoughtful about scale—sometimes a motorized Roman shade with a smaller drapery frame works better. The visual weight of the treatment has to match the architectural envelope.

From our experience: a Tribeca loft with 14-foot ceilings could carry custom drapery in a heavier fabric; a new construction studio in the same neighborhood needed something lighter to avoid feeling cramped.

— Glamour Decorating, from 30 years of NYC installs

Window frame depth and sill characteristics

Prewar windows sit in deep frames—sometimes 8 to 12 inches deep from interior wall face to glass. This depth is a feature. You can mount motorized shades or Roman shades on the frame itself, and they sit beautifully recessed. You can layer treatments—a motorized shade inside the frame, drapery in front—and it reads as intentional luxury.

New construction windows are often flush or nearly flush with the drywall. A 2–4 inch frame depth is common. Mounting inside the frame sometimes looks odd; you end up mounting on the wall itself, which changes the visual effect. Woven wood shades or Roman shades in new construction often work better wall-mounted above and beyond the window, creating height and visual drama through placement rather than architectural depth.

From our experience: a Connecticut prewar estate had such deep window frames we could install a motorized Somfy shade inside, and it looked like part of the original architecture.

— Glamour Decorating, from 30 years of NYC installs

Light control and privacy needs

Prewar apartments in dense neighborhoods—the Upper West Side, Brooklyn Heights, DUMBO—often face other buildings closely. Privacy isn't optional; it's essential. We typically spec motorized shades or Roman shades in these buildings because they offer clean, simple privacy with style. Drapery is often secondary, purely for design and light layering.

New construction in high-rises (like Long Island City or Hudson Yards) often has distance between buildings and dramatic light. Floor-to-ceiling glass creates a different priority: light control and solar heat management. This is where motorized Somfy shades excel—they can be programmed to close when the sun hits, managing passive heating and cooling. We also see more demand for Phantom Screens in new construction because the windows are larger and the view is premium. People want the option to screen out glare and insects without sacrificing the view.

From our experience: a 40th-floor new construction apartment in Long Island City needed motorized shades on a full south-facing wall; in a prewar brownstone 10 blocks away, three small windows needed complete light-blocking Roman shades for privacy.

— Glamour Decorating, from 30 years of NYC installs

Budget and timeline reality

New construction timelines are tight and predictable. Closing happens, you have 4–6 weeks to install, everything needs to be coordinated with movers. Prewar renovations are often open-ended; people live in them while renovating, which means we might install shades in phases or work around furniture and existing conditions.

Budget-wise, prewar installations cost more because they require custom sizing, careful wall assessment, and slower installation. A motorized shade in a new construction apartment with standard windows might run $1,200–$2,000 per window. The same shade in a prewar with irregular openings and plaster walls might be $1,800–$2,800. That's not price-gouging—it's the actual cost of precision work. New construction allows for efficiency; prewar demands craft.

We recommend prewar clients budget 15–20% higher than they think necessary, and plan for installation to take 20–30% longer than quoted timelines suggest. New construction? Tighter specs mean tighter budgets and faster installations.