The best thermal performance per dollar, no maintenance, and management control of the sash. Where uPVC is the right window, and where it is not.
uPVC — unplasticised polyvinyl chloride — is a rigid plastic profile, extruded with several internal chambers and reinforced with a steel core in the frame and sash. The chambers are what make it the best thermal performer per dollar: still air in five or six pockets insulates better than any metal frame and as well as wood, at a fraction of the price. It does not rot, corrode or need paint. The European tilt-and-turn version we install — Aluplast, a German system — is a serious window: multi-point locks, compression gaskets on four sides, glazing to 44 millimetres.
Its trade-offs are honest ones. The frame is the widest of the common materials, because the chambers need room. The colour is white, or a few foil laminates. A long sash in full summer sun can bow slightly if under-reinforced, which is why we specify the steel and the reinforcement, not the catalogue minimum. And it is not a Landmarks material.
The typical uPVC job is a rental building: twenty-five to a hundred units, occupied, every window replaced floor by floor. The Elston at 990 Woodycrest Avenue in the Bronx is the model — twenty-five units of Aluplast tilt-and-turn in two phases around occupancy, with the unit performance data documented for the owner’s Local Law 97 file. On a program like that the arithmetic is cost per opening times a hundred, and uPVC wins it while giving the best U-factor of the options. Key-locking handles and limiters, standard on the Aluplast system, give management control of how far the sash opens. See window replacement in NYC for how the program runs and the Bronx for the borough.
Landmarked street facades: never. Large openings: the frame width and the sash-size limits make aluminum the better choice above about five feet in either dimension. Buildings where the sightline matters — a custom house, a facade the architect designed — aluminum or clad wood. Dark colours on a sun-facing elevation: a dark foil on uPVC absorbs heat and moves more; aluminum takes dark colours without that. For the full comparison see aluminum vs uPVC vs wood vs fiberglass.
Steel reinforcement in every frame and sash member, not only where the manufacturer’s minimum requires it. Compression gaskets on four sides — the tilt-and-turn design does this; a uPVC double-hung does not seal as well. Low-E argon double glazing as the standard unit; triple where the owner is chasing a Local Law 97 number. Weep slots open and the sill flashed like any other window. Screens on the exterior in the frame rebate — the offset-sash uPVC profile is the one the flexible spring-steel screen actually fits.
For a rental or multifamily program, the best value available: the highest thermal performance per dollar, no maintenance, and a tilt-and-turn design that seals on four sides. It is not the choice for landmarks, large openings or buildings where sightlines matter.
Twenty-five to thirty-five years for the frame, in our experience; gaskets and hardware are replaced before the frame wears out. Aluminum and clad wood last longer; uPVC costs less.
Aluplast, a German tilt-and-turn system, steel-reinforced, with key-locking handles and limiters available for rentals.
Foil laminates in a few colours are available. On a sun-facing elevation dark uPVC absorbs heat and moves more than white; we recommend aluminum for dark frames on south and west faces.
Like any like-for-like replacement, not a DOB permit unless the opening changes size. Co-op and condo buildings need an alteration agreement; landmarked buildings need Landmarks approval, which uPVC will not get on a street facade.
uPVC vs Fiberglass Tilt-and-Turn Windows Window Replacement NYC The Bronx Material Comparison Energy Performance
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
Tell us the unit count and the openings. We will price uPVC and aluminum side by side, propose the floor-by-floor schedule, and document the performance for your compliance file.
