What the frame costs to run
In Lebanon, thermal performance is not an environmental gesture. It is a line on the generator bill.
Thermal performance in windows is usually discussed as an environmental question. In Lebanon it arrives first as an economic one.
Cooling is the dominant load for most of the year, and a significant part of that load runs on private generation at private generation prices. Every watt that enters through the envelope is paid for twice — once to buy the fuel, once in the equipment sized to remove the heat. A frame is not a detail in that calculation. It is part of the meter.
What a thermal break actually does
An aluminium profile without a thermal break is a conductor running from outside to inside. Whatever the outside temperature is, the inside face of the frame moves towards it. Heat crosses. In humid coastal conditions, condensation forms on the cold side, and over years that shows up as staining, corrosion and complaint.
A thermal break interrupts the metal with a polyamide bar. The frame becomes two aluminium sections held apart by something that conducts poorly. The path is broken.
The measurable result is Uf — heat transfer through the frame alone. In the profiles we work with, that figure runs from roughly 1.1 to 2.1 W/m²K depending on the family and the configuration, calculated to EN ISO 10077-2.
Where the heat actually goes
Here is the part that is usually skipped: on most windows, the frame is not the main problem. The glass is.
Frame is typically a minority of the opening by area. Glass is the rest, and its performance varies far more widely. Uw — the whole-window figure — is what the building actually experiences, and it moves mainly with the glass specification.
On a large sliding assembly we have delivered, Uw reaches 0.88 W/m²K with a centre-pane value of 0.6 and a warm-edge spacer, and 1.3 with a centre-pane value of 1.0. Same frame. Same fabrication. The difference is entirely in what was specified between the panes.
Which leads to the practical conclusion: a good frame with poor glass is a poor window, and it is a common outcome, because frames are selected early with the facade package and glass is often value-engineered late.
And in this climate the coefficient that matters most is often not U-value at all. Solar gain — how much radiation the glass admits — usually governs cooling load on any elevation that sees the sun. It is the number to argue about, and it is the one most likely to be traded away when the budget tightens.
The aluminium itself
There is a second account, separate from running cost.
Aluminium is close to infinitely recyclable, and remelting it takes a small fraction of the energy used to produce it from ore. That is a genuine material advantage, and it is not a claim about anyone's virtue — it is a property.
Our supplier holds a current, independently verified Environmental Product Declaration through the International EPD System, covering twenty-four macro-series, with a declared recycled content of 57.67 per cent across covered profiles — 33.53 per cent pre-consumer and 24.14 per cent post-consumer. Their recycled billet reaches up to 85 per cent post-consumer, which is a different figure with a different basis, and we will always say which one we mean.
One caveat, because it is the caveat that gets left out. An EPD of this kind declares per kilogram of profile. It is not a declaration about a window, and it is certainly not one about a facade. It is a rigorous number with a narrow scope, and presenting it as more than that would undo the reason it is worth citing.
The factory behind those profiles has cut its own carbon dioxide output by half against 2022, runs photovoltaic generation on the plant, and operates closed-loop water recycling. That is their work, not ours. We report it because it is part of what you buy when you buy the profile, and because it is verifiable.
What we can claim for ourselves is narrower and, on a hot afternoon in Beirut, more useful: a frame with an intact thermal break, glazed to a specification that suits the elevation it faces, installed so the seal is continuous — because a correctly specified window installed carelessly performs like a cheaper one.