A client's imported windows came in the right brand but two different profile depths, 70 mm and 80 mm, stacked in the same openings. The outside will be flat, the inside will step, and the lesson is about who you order from.
In short: A client bought windows for a new building directly from a supplier in Turkey. They arrived as Kleidco aluminum, which is a system we carry, but in two different series: some frames from a 70 mm profile line and some from an 80 mm line, stacked in the same openings. The outside can be made flat; the inside will have a 10 mm step at every joint between the two. The saving is that the joints sit about 8 feet above the floor, where few people will look. The lesson is the subject of this article: the supplier you order from decides whether the parts fit together.
The order was for stacked openings: a window with a transom or a second unit above it, the lower frame and the upper frame joined on site to read as one. The client priced the package with a supplier abroad, and the windows came in, labeled and crated, in the Kleidco system. Kleidco is a Turkish manufacturer whose profiles we fabricate and install, and the finish, hardware and glass were as ordered. What was not as ordered was the profile depth: the lower frames were made in a series just under 70 mm deep and the upper frames in a series just under 80 mm deep. The two series are not designed to be coupled to each other.
The photograph shows the joint. Both frames are black, both say Kleidco, and from the outside, once the units are set to a common line, the wall will look right. The depth difference has to go somewhere, and it goes to the inside: the upper frame stands 10 mm proud of the lower one on the room side, at every stacked opening on the job.
An aluminum window system is a family of profiles designed to work together: frame, sash, mullion, transom, coupler, sill and the gaskets and glazing beads that fit them. Each family has a fixed depth — 60, 70, 80 mm and so on — and everything in it is drawn around that depth. Two families from the same manufacturer share a look and a hardware groove, but they do not share a coupler. A 70 mm frame set against an 80 mm frame leaves a 10 mm ledge on one face or the other; there is no accessory that makes it disappear.
On this job the saving grace is geometry: the stacked joints are about 8 feet above the finished floor, above eye level and mostly behind window treatments. A trim profile on the inside will cover the step and the client will live with it. Had the mix been at sill height, or in a stacked door and sidelight, the only fix would have been to reorder one set of frames.
This is not a fault in Kleidco. Every system house makes several series, and all of them are correct products. The fault is in the ordering: a supplier who did not check that the units for one opening came from one series, and a buyer who had no way to check it, because the quote listed window sizes and a brand name, not the profile series. The same thing happens with Cortizo, Reynaers, Alutech and every other manufacturer with more than one depth on the price list. We wrote about how the chain between factory and job site works in how windows are really sold; this is what a missing link in that chain looks like on site.
If you are buying windows abroad to save money, ask the supplier one question before paying: which profile series is every unit on this order, and are the stacked units in the same one? If the answer is a brand name instead of a series, keep asking. Or send us the opening list and we will quote the same windows with the series written down and the drawings to prove it — see factory-direct windows and doors and material supply.
The frames are being installed with the exterior faces flush and the weather seal continuous. On the inside, the 10 mm step at each stacked joint will be covered by a black aluminum trim that runs the width of the opening, finished to match RAL 9005, so the joint reads as a deliberate shadow line rather than a mistake. The client keeps the windows, the schedule and most of the saving; we keep a photograph for the next person who asks whether the supplier matters.
Not with a system coupler, because the two series are not designed for each other. The exterior faces can be aligned and the 10 mm difference covered on the inside with trim, which is a workaround, not a detail.
No. Kleidco makes several correct series; the problem is an order that mixed two of them in one opening without anyone checking. The same happens with any manufacturer that offers more than one profile depth.
Ask the supplier for the profile codes on the order confirmation, or for shop drawings showing the frame and coupler sections. A quote that lists only sizes and a brand name does not tell you.
The exterior seal can still be made continuous. The glazing pocket, gaskets and thermal line change at the joint, so the stacked assembly is not one that has been tested as a unit.
The system and profile series for each opening, the glass make-up, the hardware, the color and the finish, plus drawings for any stacked or coupled openings. That is how we quote; see our design and drawing service.
Kleidco How windows are really sold Design, planning and drawings Non-branded aluminum systems Factory-direct windows and doors Material supply Request a quote
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 us the opening list and the quote you have. We will tell you what series it is, whether the stacked units match, and quote the same windows with the drawings to prove it.
