Energy Efficiency Showdown: Cortizo Double Glazing vs PVC & Timber in Portugal

With Portugal's mix of hot summers, damp winters, and strong coastal winds, window insulation is a vital factor in home comfort and energy efficiency. Homeowners often ask: Is aluminium, PVC, or timber the best choice for double glazing in Portugal? This blog dives deep into the energy performance, insulation capability, durability, and long-term value of each- highlighting why Cortizo aluminium systems are emerging as the premium standard.

Comparing Frame Materials: Aluminium, PVC, and Timber

Aluminium (Cortizo)

Modern aluminium frames—like those offered by Cortizo—are thermally broken, meaning they include an insulation barrier that prevents heat transfer between inside and outside. Combined with double glazing, these systems offer U-values as low as 1.0 W/m²K. Cortizo also uses high-quality gaskets and precision sealing to reduce air leakage and moisture ingress.

Key advantages:

• Strong structural integrity for large spans

• Slim sightlines that let in more natural light

• Excellent resistance to warping and weathering

• Minimal maintenance

PVC

PVC windows have traditionally been favoured for their affordability and low conductivity. However, in Portugal's sun-intense environment, cheap PVC frames can discolour, warp, or degrade over time. They also lack the sleek aesthetic of aluminium and may not be suitable for larger panes.

Typical drawbacks include:

• Bulkier profiles reduce light penetration

• Limited colour options

• Questionable longevity in coastal zones

Timber

Timber frames can provide strong insulation, especially when combined with modern glazing. However, they require regular maintenance—including repainting, sealing, and treating against rot, pests, and humidity. In Portugal's climate, this upkeep can be frequent and costly.

Challenges with timber:

• Swelling and shrinking with humidity

• Potential for rot and insect damage

• High maintenance overhead

U-Value & Thermal Performance Comparison

Frame Material	Typical U-Value (with double glazing)	Maintenance Level	Climate Resistance
Cortizo Aluminium	~1.0 W/m²K	Low	Excellent (UV/salt/humidity)
PVC	1.3–1.6 W/m²K	Low to Medium	Fair (may degrade in heat/UV)
Timber	1.2–1.4 W/m²K	High	Variable (affected by moisture)

Cortizo consistently achieves superior insulation without the size, aesthetic, or durability compromises seen in PVC and timber.

Acoustic and Airtightness Benefits

Cortizo aluminium frames use multi-chamber profiles and EPDM gaskets, delivering excellent acoustic insulation and airtightness. This makes them ideal for:

• Urban homes (e.g. Lisbon, Porto)

• Coastal villas exposed to wind

• Properties close to roads or tourist hotspots

PVC and timber can offer decent acoustic dampening, but gaps or warping from wear reduce long-term performance.

Sustainability and Lifecycle

Recyclability & Longevity

• Aluminium: 100% recyclable and lasts over 40 years with minimal maintenance.

• PVC: Recyclable but prone to performance degradation.

• Timber: Renewable but often replaced every 15–20 years due to decay.

Environmental Footprint

Cortizo aluminium is powder-coated (not painted), reducing emissions and increasing UV resistance. Modern thermally broken aluminium now rivals wood in insulation without the environmental strain of tropical hardwoods or the plastic waste of PVC.

Real-World Application in Portugal

Region	Climate Concern	Best Performer
Algarve	Salt corrosion & heat	Cortizo aluminium
Lisbon	Urban noise & temp fluctuation	Cortizo aluminium
Porto/North	Rain & humidity	Cortizo or high-grade timber (if maintained)

Why AltaGlaze Recommends Cortizo for Portugal

• We exclusively install thermally broken Cortizo aluminium systems for long-lasting, high-performance results.

• All installations meet or exceed local energy requirements and passive solar design goals.

• Our systems offer unmatched weather resistance for Portugal’s varied climates.

FAQ

Isn’t aluminium less efficient than PVC or wood?

Not anymore. Thermally broken aluminium systems like Cortizo rival or outperform PVC and timber while offering superior lifespan and aesthetics.

Will aluminium frames get hot in the sun?

No. Cortizo’s thermal breaks and coatings prevent interior heat transfer, maintaining indoor comfort.

Are Cortizo windows worth the investment?

Yes. They offer long-term energy savings, reduced maintenance, and increased property value.

Conclusion

Cortizo aluminium double glazing systems stand out as the energy-efficient, durable, and stylish solution for Portuguese homes. Compared to PVC and timber, they deliver better insulation, longer lifespan, and reduced maintenance—all without compromising architectural appeal. For homeowners seeking smart, long-term upgrades, Cortizo—installed by AltaGlaze—is the clear winner.