Choosing an aluminium system often starts with “which series is best?”. The right question is different: what must the unit achieve on this particular project. The answer determines profile depth, glazing type, hardware and, ultimately, cost. Below is the sequence we use when selecting systems for residential and commercial projects.
1. Establish the thermal requirement
In Ukraine the minimum reduced thermal resistance of building envelope elements is set by DBN V.2.6-31:2021 (opens in a new tab) “Thermal insulation and energy efficiency of buildings”, in force since 1 September 2022. For glazed elements of residential and public buildings it is 0.90 m²·K/W in temperature zone I and 0.70 m²·K/W in zone II.
Thermal resistance R and thermal transmittance U are inversely related: R ≈ 1/U. So in zone I the Uw of the whole unit should be no higher than roughly 1.1 W/(m²·K). This is the first bar the system must clear.
2. Assess loads and operating conditions
Height and wind. Wind loads on the upper floors of a high-rise are far higher than on a private house. Wind resistance is classified to EN 12210 — classes 1 to 5 with a letter A, B or C for permitted deflection.
Rain. Watertightness to EN 12208 — from 1A to 9A (600 Pa) and above, with E classes for pressures over 600 Pa.
Airtightness. Air permeability to EN 12207 — classes 1 to 4, where 4 is best.
Security. For ground floors and entrances consider a burglar-resistance class to EN 1627 (RC2, RC3).
The manufacturer declares these classes in the declaration of performance under DSTU EN 14351-1:2020 (opens in a new tab).
3. Choose the unit type
Window, door, sliding unit or facade — these are different systems with different logic. For storey-height panoramic glazing a stick curtain wall is often more sensible than coupling several large windows. For a terrace exit a sliding system beats swing doors for wide openings.
4. Choose the profile series
Within one system type manufacturers offer series with different build depths and insulation levels. As a rule, the deeper the profile and the wider the thermal break, the lower the Uf — and the higher the cost. For most zone I housing a mid-range series with a good glazing unit is enough; “passive” series make sense for nearly zero-energy buildings.
5. Choose the glazing unit
Glass usually covers most of a window’s area, so its Ug has the largest effect on Uw. Triple glazing with a low-e coating and argon is a typical choice for zone I. Mind the spacer: a warm-edge spacer instead of aluminium noticeably cuts heat loss at the glass edge and the risk of condensation.
For safety use laminated glass where impact is possible and toughened glass where thermal stress or large sizes are involved.
6. Hardware and operation
Hardware decides how the unit will work in ten years. Check the permitted sash weight, micro-ventilation, opening restrictors (especially for schools and hotels) and adjustability.
7. Colour and finish
RAL powder coating, anodising or textured finishes are not only about looks. Coastal and aggressive environments need special coating specifications.
Typical mistakes
Comparing systems by profile price per metre only. The unit cost includes profile, glazing, hardware, finish and labour; a cheaper profile may need more expensive glass to meet the code.
Looking at Uf instead of Uw. The code is checked for the whole unit, not the profile alone.
Ignoring glass weight. Large triple-glazed units are heavy; if the hardware is not rated for the weight, the sash will sag over time.
Choosing the colour last. Special finishes, dual-colour profiles or anodising affect lead times — decide together with the system.
Forgetting installation. Even the best system loses performance if the wall junction is not detailed and the window sits outside the insulation plane.
Summary
The right sequence runs from requirements to system, not the other way round: thermal requirement and loads first, then unit type, series, glazing, hardware and finish. That way the unit meets the codes without paying for performance the project does not need.
Need help with selection? Send us your drawings or get an estimate in the online calculator.