UV protection curtain: protect furniture and floors from the sun

How UV rays damage your interior (even on cloudy days)

Solar radiation entering through a window contains three types of rays: visible light, infrared (heat), and ultraviolet. It's UV rays, invisible to the eye, that cause the most lasting damage to your interior:

• Fabric fading: sofa, decorative curtains, cushions, rugs. UV rays break the chemical bonds of textile dyes. A sofa exposed to direct sunlight loses 20-40% of its color intensity in 2-3 years (source: Textile Research Journal studies on fiber photodegradation).
• Yellowing and cracking of wood: flooring, furniture, frames. UV rays degrade the lignin in wood, causing irreversible yellowing followed by surface micro-cracks. Flooring exposed to direct sunlight shows visible color differences in 6-12 months (areas under furniture vs. exposed areas).
• Degradation of artworks and objects: paintings, photographs, books. Museums use glazing that filters 99% of UV rays to protect collections, proving that radiation is destructive even at low intensity.

Important point: UV-A rays penetrate glass and clouds. On cloudy days, 80% of UV-A reaches the ground. Your interior is exposed 365 days a year, not just in bright summer sun. Standard double glazing filters approximately 25-40% of UV rays, allowing 60-75% of harmful radiation to pass through.

What each anti-UV solution actually blocks

Key point: a closed thermal blackout curtain blocks almost all UV rays (99-100%) because the dense fabric allows no radiation to pass through. It is the most effective and least expensive solution, but it requires closing the curtain. The advantage over film or treated glazing: you open the curtain when you want light, and close it when the sun directly hits the window.

Solution 1: The thermal blackout curtain, maximum and flexible UV protection

A high-density blackout curtain (500 g/m² and more) blocks 99-100% of UV rays when closed. The reason is simple: the multi-layer fabric lets no light through, and therefore no ultraviolet radiation. It is physically the most complete barrier possible.

The decisive advantage of the curtain over other anti-UV solutions: flexibility. A solar film or treated glazing filters UV rays constantly, even when you want to enjoy the sun. The curtain can be drawn and closed at will:

• Direct sun on the window (10 am-6 pm depending on orientation): curtain closed, total protection for furniture and flooring.
• Morning or evening (soft light, indirect sun): curtain open, natural light in the room.
• Night: curtain closed, 100% blackout* for sleep + thermal insulation.

Kurtens' made-to-measure thermal blackout curtains (620 g/m²) combine total UV protection, 100% blackout*, thermal insulation up to 7°C*, and sound attenuation of 22 dB*. A single curtain that protects your furniture, blocks heat, eliminates light, and reduces noise.

Solution 2: Anti-UV film on glass, permanent and transparent protection

An anti-UV film is applied to the inside of the glass and filters 95-99% of ultraviolet rays while allowing 70-90% of visible light to pass through. This is the solution for those who want permanent protection without altering the brightness of the room.

Advantages: invisible once installed, does not hinder window opening, 24/7 protection even with the curtain open.

Limitations:

• Slightly reduces brightness (10-30% depending on the film)
• Can create an overheating effect between the film and the double glazing, which risks damaging the glazing seal. Some window manufacturers void the warranty if a film is installed.
• Delicate installation (air bubbles, dust): a clean result often requires a professional (80-150 euros per window).
• Lifespan: 5 to 15 years depending on the quality of the film and exposure.

Cost: 15 to 50 euros per window for DIY installation, 80 to 150 euros with a professional.

Film and curtain are complementary: the film protects against UV even when the curtain is open, and the curtain adds thermal protection and blackout when the sun directly hits.

Solution 3: Anti-UV glazing, the high-end solution

Some glazings incorporate an anti-UV treatment into the mass of the glass, filtering 95-99% of UV rays while retaining 90-95% of visible light. This is the most transparent solution but also the most expensive: 300 to 800 euros per window, requiring complete replacement of the glazing.

This solution is relevant in two cases: new construction (integrate the treatment when installing the windows) or complete renovation of joinery (take advantage of changing the glazing to add UV treatment). For an existing home without a renovation project, thermal curtains or anti-UV film offer a much better cost/efficiency ratio.

Protecting the most exposed rooms: living room, office, bedroom

Living room with south or west-facing bay window

This is the most critical configuration. A 3 m² bay window facing south receives 4 to 6 hours of direct sunlight in summer. The sofa, flooring, and furniture facing the bay window suffer the fastest damage. Priority solution: a made-to-measure bay window curtain closed during direct sunlight hours, open the rest of the time.

Office with screen facing the window

UV rays not only threaten furniture: they also create glare on screens and visual fatigue. A blackout curtain allows for perfect light control when working on a screen. The NF EN 12464-1 standard recommends 300 to 500 lux for screen work: a half-closed thermal curtain filters glare while maintaining sufficient lighting.

Bedroom with light-colored flooring

Light-colored flooring (bleached oak, pine, birch) is most susceptible to UV yellowing. Areas under the bed and furniture remain light, while exposed areas gradually darken, creating visible demarcations. A blackout curtain closed during the day during direct sun hours protects the floor while keeping the room at a good temperature for sleeping in the evening.

What to remember

UV rays pass through your windows 365 days a year, even on cloudy days, irreversibly degrading furniture, flooring, and fabrics. Standard double glazing only filters 25-40% of UV rays, which is insufficient to protect an exposed interior.

The most effective and flexible solution: a high-density thermal blackout curtain (500 g/m² and more) that blocks 99-100% of UV rays when closed, with the freedom to open it when you want light. Combined with an anti-UV film (permanent protection even with the curtain open), you get complete protection.

Discover our made-to-measure thermal blackout curtains: 620 g/m², total UV protection, 100% blackout*, thermal insulation up to 7°C*, and sound attenuation of 22 dB*. 7 colors, manufactured to the exact dimensions of your window, free delivery in 2 to 3 weeks. To choose the right color, consult our color guide.

*Data from tests performed under optimal conditions.

Frequently Asked Questions

Beyond solar protection, find all the methods to bring the temperature down in our guide on how to cool a room without air conditioning.