uPVC doors and windows: 10 things to know before you buy, FAQs and answers

1. What exactly are uPVC windows and doors?

uPVC, short for unplasticized polyvinyl chloride, is one of the top materials used for modern window and door frames. And with good reason: it’s non-toxic, fully recyclable and free of carcinogenic substances, making it safe and suitable for virtually any space.

From a performance perspective, high-quality uPVC windows don’t rust, swell or discolor over time. They’re extremely resistant to humidity, rain, UV rays and temperature fluctuations, which makes them ideal for both warm and cold climates.

Another major advantage is this: uPVC frames provide excellent thermal and acoustic insulation, helping reduce energy consumption while improving indoor comfort. They also help to block out external noise, thanks to the sound-dampening properties of the material.

And let’s not forget about cost: compared to wood or aluminum frames, uPVC doors and windows offer one of the best value-for-money options on the market.

2. Types of uPVC frames: what are the options?

When we talk about uPVC doors and windows, we’re not referring to a single, standard frame model. uPVC offers a wide range of customizable solutions, adaptable to virtually any architectural style or functional requirement.

There are two main configurations for uPVC window systems:

• Windows with subframes, typically installed into pre-existing wall openings;
• Monoblock window frames, which include an integrated insulated shutter box and guides for external blinds.

In terms of dimensions, there are very few limits: uPVC allows for the creation of windows and doors in various heights and thicknesses, with either minimal or reinforced profiles, depending on insulation and structural needs. It’s also possible to create non-standard door and window shapes, as well as slim central mullions to let in more natural light.

In practice, uPVC can be used to manufacture almost any type of frame:

• Standard windows, bottom-hinged windows or fixed windows;
• French doors and balcony doors;
• Entrance doors;
• Sliding doors (lift-and-slide, tilt-and-slide, parallel sliding);
• Both interior and exterior shading systems.

What makes uPVC stand out is design flexibility: it fits seamlessly into both modern and traditional contexts, new builds and renovations, combining functionality and style.

3. Are uPVC windows and doors good for me?

uPVC is one of the most versatile materials. It provides excellent thermoacoustic insulation, stands up well to the weather and requires virtually no maintenance.

It’s a lightweight yet durable material, perfect for a wide range of customizations. uPVC windows and doors are available in a broad selection of colors, wood-effect finishes, painted options, and even dual-color combinations to match interiors and exteriors.

What about the downsides? They tend to depend more on design choices:

• uPVC is not ideal for very large or very small window openings, unless reinforced profiles or composite uPVC/aluminium systems are used.
• In extremely hot or sunny climates, it’s often better to opt for uPVC/aluminium frames to prevent warping or material fatigue.
• Quality matters: low-cost or uncertified uPVC frames may offer poor performance in terms of insulation, durability and finish.

4. Why do uPVC windows get condensation and mold?

Condensation forming on your window panes after replacing old frames is not a defect; it’s actually a sign that your new insulation is doing its job properly.

Modern uPVC windows are designed to seal the indoor environment, retain heat and improve energy efficiency. The issue arises when, in a well-insulated and airtight space, humidity generated inside the home has nowhere to go. Activities like cooking, showering, drying clothes, or simple breathing, release moisture into the air.

If the rooms aren’t properly ventilated, that moisture settles on the coldest surfaces and creates condensation: over time, this can lead to mold in corners or behind furniture.

To prevent condensation on windows, a few simple habits can make a big difference:

• Open the windows 2-3 times a day in every room, even just for a few minutes.
• Use the tilt-and-turn opening (vasistas windows) for more consistent airflow.
• In very humid or poorly ventilated areas, consider windows with micro-ventilation.

5. Curtains and shading systems: what works best?

It’s a more common question than you might think. With old wooden windows, all it took was a screw to fix a curtain rod; but when it comes to uPVC, drilling into the frame is not a good idea as it can compromise insulation, airtightness or even void the product warranty.

Here are the best shadings systems you can use without damaging your uPVC windows:

• Adhesive or pressure-fit brackets for curtains, installed directly on the sash or glass;
• Roller blinds or panel curtains mounted on the wall or ceiling (not the window frame);
• Interior uPVC shutters, fitted inside the window recess with side-hinged opening;
• Integrated blinds or pleated shades inside the glazing unit: a high-tech, maintenance-free option, ideal for offices or modern interiors;
• External shading systems (uPVC or aluminium shutters, louver or roller shutters): these protect from sunlight and increase privacy, eliminating the need for curtains.

6. How long do uPVC doors and windows last?

uPVC windows and doors, when properly selected and maintained, are a long-term investment, often lasting an entire generation. High-quality uPVC frames have an average lifespan of 30 to 35 years, provided they’re correctly installed and certified.

As proof of their durability, top manufacturers offer up to 10 years of warranty coverage for doors and windows, which includes both integrity and performances. Some finishes and colors even come with extended warranties against yellowing or discoloration.

Naturally, to preserve their performance over time, it’s important to follow basic care instructions: regular cleaning, occasional maintenance and avoiding any tampering.

7. What is the best energy rating for uPVC windows?

When we talk about energy efficiency, we’re referring to the thermal performance of the entire window (frame, glass and installation). Ratings usually range from A4 (most efficient) to G (least efficient), and in this regard, uPVC is among the top-performing materials.

High-quality uPVC doors and windows can reach very low thermal transmittance values (U_w even below 1.0 W/m²K), making them suitable for low-energy buildings and houses.

To achieve the best energy rating, it’s important to choose an advanced uPVC frame, combine it with high-performance glazing, ensure the window is certified for security and insulation, and most importantly, make sure it’s installed professionally.

8. How are uPVC doors and windows installed?

The performance of a uPVC window or door frame depends not only on the quality of the material or design, but largely on how it’s installed. Proper fitting involves many key steps:

• Checking and preparing the wall opening;
• Precise positioning, leveling and secure anchoring of the frame;
• Use of certified insulating materials;
• Compliance with thermal and acoustic insulation standards.

This is not something you can improvise or do on your own. A proper door and window fitting requires experience, technical know-how and specialized tools: otherwise, the result may include unpleasant drafts, leaks, thermal bridges or fogged-up glass.

Some manufacturers even offer certified installation services, such as those following CasaClima protocols, to guarantee a professional and high-quality workmanship.

9. How to maintain uPVC windows and doors?

uPVC door and window frames are built to withstand the elements and last for decades, but that doesn’t mean you can neglect them. Simple, regular maintenance is essential to preserve their appearance, performance and durability over time.

Here are a few practical tips to protect your uPVC windows and doors:

• Clean the frames with a soft cloth and a mild detergent every 6 months; avoid abrasive products or chemical solvents that may damage the surface.
• Wipe down the window glazings monthly using microfiber cloths and glass-specific cleaners (ideally ammonia-free).
• Dust and inspect the seals to ensure airtightness and water resistance.
• Lubricate the hardware once a year with a product designed for windows, especially for tilt-and-turn openings, sliding doors and entrance doors.

10. How much should uPVC windows cost?

The price of uPVC doors and windows is not calculated solely by square meter, as it depends on several factors, such as the type of opening (fixed, casement, sliding), the frame specifications (profile thickness, number of chambers, sealing gaskets), the glass type (standard, low-emissivity, anti-burglary), the finish (mass-colored, wood effect, bicolor), the energy performances, as well as any certifications for safety or insulation.

The purchase of uPVC frames may also be eligible for several financial incentives, which may vary from each country: for example, in Italy you can count on many options, such as “Bonus Casa” or “Ecobonus”, “Conto Termico 3.0” or zero-interest financing.

PLUS: Who makes the best uPVC windows and doors?

The answer is simple: those who combine experience, quality and innovation.

Since 1967, DQG has been producing and installing uPVC and uPVC/aluminium windows and doors, entirely Made in Italy within its manufacturing plant. With more than 30.000 frames produced annually for private homes, residential buildings, large construction sites and international projects, DQG is now a benchmark in the industry.

What exactly makes our products unique?

• A complete range of windows and doors, sliding systems and shutters;
• Advanced frame systems certified up to RC3 security class;
• A wide selection of finishes and colors, effects and custom options;
• Qualified fitting according to PosaClima international standards;
• Extended warranties, up to 13 years on color stability and 10 years on performance.

DQG is more than just a manufacturer. We’re a technical partner for private owners, designers and retailers who want the best durability and energy efficiency.

If you’re wondering who makes the best uPVC doors and windows on the market, choose those who have been doing it for over 50 years: DQG.