How to choose windows? This is a question many people overlook when planning to build or renovate a house or apartment. Yet the type of windows you choose has a huge impact – not only on the look of your home, but also on security, comfort, and energy bills. If you’re facing this decision now, let us guide you through it. Trust our experience!
Anyone building, remodeling, or replacing windows at home faces a dilemma: should you go for the cheaper option and risk having to replace the windows again in the near future, or invest in higher-quality products that guarantee long-term comfort and energy savings?
As Sławomir Lejk, Project Manager at Bertrand, points out, this decision is rarely easy—budget always plays a role, and low-cost products can seem tempting. When he chose the first windows for his own home, he went with PVC because of their attractive price and steadily improving technical performance, which today can rival other materials.
Price isn’t everything
Still, cost should never be the only factor. As our Premium Customer Advisor stresses, you also need to consider acoustic and thermal insulation as well as safety. A few years back, when he was choosing windows for his home, he opted for Bertrand’s Kombisystem—not only because of his professional background, but also because he knew the production process and the quality of materials firsthand. And while he acknowledges competitors, his knowledge of Bertrand’s durable solutions made the choice an easy one.
Step 1: define your needs and location
Type of building & location – Before you look at specific models, think about the purpose of the building (energy-efficient home, classic single-family house, or apartment) and where it’s located. For example, windows for a high-rise apartment require different parameters than those for a country house. Don’t forget to consider sunlight exposure—large south-facing windows often need solar protection.
Set your priorities – Decide what matters most: energy efficiency, noise reduction, safety, aesthetics, or eco-friendliness. Having clear priorities makes conversations with your advisor much more effective.
Step 2: key technical parameters
Thermal transmittance (U-value) – The lower the Uw value, the less heat escapes through the window. In modern homes, windows should reach Uw ≤ 0.9 W/(m²·K). Triple glazing, warm-edge spacers, and argon gas fills help achieve this. By 2025, advanced glazing and warm spacers have become standard for passive houses.
Glass types & coatings – Low-emissivity coatings (such as ECLAZ) improve both insulation and light transmission. Selective glass helps reduce overheating. In noisy locations, choose glass packages with high acoustic insulation (Rw > 45 dB).
Frame materials:
PVC – Affordable, great insulation, low maintenance. Needs reinforcement for durability.
Aluminum – Strong, weather-resistant, allows slim frames. Modern systems use insulating inserts and multi-chamber profiles for good Uw values.
Wood – Elegant, natural, and insulating, but pricier and requires maintenance. In 2025, certified wood and hybrid solutions (aluminum outside, wood inside) are popular.
Hardware & safety – Security depends on the locking points and hardware class (RC1, RC2, RC3). Large windows may require tempered or laminated glass and lockable handles. Consider integrating sensors with your alarm system.
Ventilation & tightness – Windows should allow for micro-ventilation. Energy-efficient homes require controlled air exchange. Proper sealing with vapor-tight and vapor-permeable tapes ensures performance.
Learn more about technical window parameters
Step 3: energy-efficient & passive windows
With rising energy costs and growing interest in sustainable building, passive windows are becoming the new standard. By 2025, triple glazing with warm-edge spacers is common, minimizing thermal bridges and cutting energy loss. These windows reduce heating bills and support eco-friendly living.
Step 4: large-format glazing & minimalist design
Modern architecture favors floor-to-ceiling glass walls, panoramic windows, and sliding systems that connect indoor and outdoor spaces. Slim profiles and hidden hinges create a sleek look. Color trends lean toward nature-inspired palettes: white, grays, black, and wood-like finishes, often in matte textures instead of glossy.
Read more about large-format glazing
Step 5: technology & personalization
Windows today can be part of a smart home—automated, alarm-integrated, and equipped with sensors. You can also personalize finishes with trendy colors (like anthracite), wood textures, concrete effects, or anodized coatings.
Common mistakes to avoid
Ignoring energy efficiency – Poor glazing can cause heat loss in winter and overheating in summer. Always check Uw, Ug, Uf, and warm-edge spacers.
Overlooking security – Large windows need reinforced glass and anti-burglary hardware.
Forgetting structural requirements – Heavy glazing requires special load-bearing elements. Skipping this can damage the building.
Improper installation – Even the best windows fail if poorly installed. Experts say 70% of success comes from correct installation. Proper sealing, supports, and foams are essential.
Skipping sun protection – Without shades or selective glass, interiors overheat in summer.
Clashing with the home’s style – Windows should match the architecture and balance proportions.
A step-by-step window selection guide
Analyze your needs – Budget, parameters, style, and room functions. Consult your architect about structural requirements.
Choose material & system – PVC, aluminum, wood, or hybrid. Compare performance and look. For energy-efficient homes: triple glazing with Uw ≤ 0.9 W/(m²·K).
Select the right glass package – Thermal, acoustic, and solar control adapted to your location. Modern triple glazing can reach 77–79% light transmission (LT).
Safety & ventilation – RC2/RC3 hardware, lockable handles, optional sensors, and micro-ventilation.
Colors & finishes – In 2025, matte gray, anthracite, black, and wood-like textures dominate.
Manufacturer & installation – Choose a trusted company with certified products and professional installation. Provide building plans for tailored solutions.
Service & warranty – Ask about warranty terms and maintenance. Regular check-ups and care (lubricating hardware, adjusting seals) extend lifespan.
How to choose windows with Bertrand experts?
Windows are not a seasonal purchase—they’re a long-term investment. At Bertrand, our consultants, like Sławek, will guide you through every step: from analyzing your needs to selecting the best system, colors, and ensuring flawless installation.
Our team combines experience with cutting-edge knowledge of the latest technologies, energy efficiency standards, and safety requirements. Since we see firsthand how these products are made, you can trust that your windows will be perfectly tailored to your home.
If you’re building a new house or thinking about replacing your old windows, reach out to a Bertrand advisor. You’ll get professional guidance and avoid costly mistakes.