The material Landmarks expects and the one that lasts longest maintained. Clad or solid, which lines we install, and what gets approved on a historic street.
Every window in New York built before the middle of the last century was wood, which is why wood is what the Landmarks Preservation Commission expects on a historic street facade and why the double-hung is its shape. Wood insulates well, is stable, and can be milled to any profile — including the exact profile of the original in a landmark district. It is also the most expensive of the four common frame materials and the only one that needs paint.
Clad wood solves the paint problem: a wood frame and sash with an aluminum or fiberglass skin on the exterior, factory-finished, and the wood exposed inside. It is what we install in nearly all landmark work — Pella, Marvin and Andersen all make clad lines — and what a co-op board usually specifies when it says “wood.” Solid wood inside and out is for the restoration purist and the owner who will keep up the painting.
| Line | Exterior | Character | Where we have used it |
|---|---|---|---|
| Pella Reserve / Architect / Lifestyle | Aluminum-clad or wood | Traditional profiles, divided lites, casements and double-hungs | 343 Hoyt Street, Coleridge Street, Amherst Drive |
| Marvin Ultimate / Signature | Aluminum-clad or wood | Landmark-grade double-hungs; Low-E3 argon; ENERGY STAR | East 70th Street |
| Andersen 400 / E-Series | Vinyl-clad (400) or aluminum-clad (E-Series) | Wide range; E-Series for custom colours and sizes | Andersen |
On a street facade in a historic district, Landmarks reviews the material, the operating type, the profile of the frame and sash, the muntin pattern and width, and the glass. Clad wood is routinely approved when the profile matches the original; the aluminum cladding is accepted because it reads as painted wood from the street. Simulated divided lites with an exterior bar, interior bar and spacer bar between the glass are the standard approval; grilles between the glass alone usually are not. We measure the original, draw the profile, and submit the application with the drawings — see landmark window replacement in Carroll Gardens and Upper West Side landmark windows.
A pocket replacement inside the old frame shrinks the glass and leaves the old frame’s air leaks; on a landmark facade it is also usually refused, because the old frame stays visible. Landmark wood windows are installed brick-to-brick: the old frame comes out to the masonry, the new full-frame unit goes in, the perimeter is insulated, flashed and sealed, and the interior trim is rebuilt. It is the more expensive method and the only one that gives the new window the whole opening. See brick-to-brick or pocket.
Large modern openings and window walls: aluminum. Rental programs where cost per opening decides: uPVC. Oceanfront exposure without a clad exterior: no. For the full comparison see aluminum vs uPVC vs wood vs fiberglass. Where a house wants the look of clad wood at a lower price, the Pella and Marvin fiberglass lines are worth pricing.
Both have a wood frame and sash. Clad wood adds a factory-finished aluminum or fiberglass skin on the exterior so the outside never needs paint; the wood is exposed inside. Solid wood is finished on both faces and needs exterior paint every few years.
Routinely, when the profile, operating type and divided-lite pattern match the original. The cladding reads as painted wood from the street. We prepare the application with profile drawings.
Pella, Marvin and Andersen, in their clad and solid-wood lines. Members of our installation team have completed Marvin installation training.
Maintained, longer than any other material — many New York wood windows are a century old. Clad wood removes the maintenance. Hardware and weatherstripping are what wear.
Yes. Wood insulates about as well as uPVC, and with Low-E argon glazing a clad wood window meets the energy code with margin. Marvin Ultimate units on East 70th Street are ENERGY STAR rated.
About this page. Written by Alex GC Inc. d/b/a Alex Glass Construction and reviewed before publication by Aleksandr Chernovolenko, Managing Partner, with our design and estimating lead and a field foreman. Our foremen hold the NYC DOB Site Safety Training supervisor card and our crews the 40-hour worker card; we are certified to fabricate, install and service Alutech and Everest aluminum systems. Facts are drawn from our own projects, manufacturer test data and the applicable codes; where we are giving an opinion, we say so. Last reviewed September 2026. Credentials
Send a photo of the facade and the existing window. We will tell you which line matches, what Landmarks will want, and quote brick-to-brick.
