Premium aluminium windows — what actually makes the difference

A premium-class aluminium window isn’t just about the frame material. It’s the sum of the details: the width of the thermal break, the number of chambers, the hardware class, how the glass is set, and the quality of the finish. Below we break these down into factors you can actually see and feel in use — not just read on a spec sheet.

Insulation

PROMOST aluminium window systems come in three thermal-insulation levels: without a thermal break (interior partitions, shop fronts), with enhanced insulation (commercial buildings, Uf 1.3–2.0 W/m²K), and with full thermal insulation. In this last variant the Uf coefficient goes down to 0.5 W/m²K, and the whole window (Uw) reaches passive-house level — thanks to wide thermal breaks, additional chamber fillers (including aerogel), and three planes of EPDM sealing. See the full comparison of variants, with a parameter table, in the window systems and thermally insulated systems descriptions.

Slimness and glazing

Premium means maximum glass and minimum frame — large panes, narrow visible profiles, triple-glazed units up to 35 mm. In practice that means fewer divisions in the window, more natural light in the room, and a lighter, more contemporary façade line — without compromising leaf stiffness, which is governed by profile geometry and internal reinforcement, not by its visible width.

Hardware and mechanisms

Hardware class translates directly into a window’s lifespan: the number of open-close cycles without losing adjustment, load resistance for large leaves, and smoothness of operation. Premium variants use hardware with three-plane adjustment (compression, height, side) — this lets you correct the leaf’s position after years of use without replacing parts, which matters a great deal for large, heavy panes.

Finish

The full RAL palette, structural colours, anodised effects, and a bi-colour option (a different colour outside and inside) — the shade and texture are matched to the specific façade, not picked from a closed list of “standard” colours. The same level of finish applies to aluminium doors on the same project, so windows and the entrance can be colour-matched consistently.