The Spanish sun can be beautiful, but it can also make your home unbearably hot. If you're tired of closing blinds, running the air conditioner all day, or watching your furniture fade, solar window film is the smart and affordable solution.

At Solar Window Film Spain, we install high-quality solar control films that reduce heat, glare, and UV radiation — helping you enjoy the light without the discomfort. Our films are made in the USA and installed by professionals with more than 50 years of experience in the window film industry.

At Out of the Sun – Solar Window Film Spain, our expert installers always assess your glass type first to determine whether interior or exterior installation is the safest and most effective solution.

Interior vs. Exterior Solar Window Film — What’s the Difference?

Choosing between interior and exterior solar window film is essential to ensure the best performance and glass safety. While both types effectively reduce heat, glare, and UV rays, the correct placement depends on the type of glass and exposure to sunlight.

Interior solar window film is installed on the inside surface of the glass. It’s the most common type of installation because it’s protected from weather and provides excellent heat rejection, UV protection, and glare control. This option is ideal for standard single- or double-glazed windows in homes, offices, and apartments.

Exterior solar window film, on the other hand, is applied to the outside surface of the glass. It’s used when the inner surface cannot safely absorb extra heat — such as with reinforced or tempered glass, laminated glass, roof windows, skylights, or large sliding doors. These glass types are designed for strength and safety (for example, so people can’t be injured if they accidentally walk into them). However, they already retain more heat, and applying film on the inside could cause thermal stress or even cracking.

How to check what type of glass you have:

You can usually find a small engraving or printed marking in one corner of the glass. If it says “Tempered,” “Safety Glass,” “ESG,” or “Toughened”, your window is reinforced and therefore requires exterior film installation.

If you’re unsure, our experts at Out of the Sun in Spain can easily determine your glass type during a free inspection — ensuring the correct installation method for lasting performance, safety, and warranty coverage.

The Simple “Sound Test” — How to Tell What Type of Glass You Have

If you’re unsure whether your windows need interior or exterior solar window film, one easy way to check the glass type is by performing a sound test. This quick, non-invasive method helps identify whether your window is single-glazed, double-glazed, laminated, or tempered/reinforced — which determines the correct film installation.

Here’s how to do it:

• Tap the glass gently with your knuckle or a pen.
• A clear, sharp “ping” sound usually indicates NON reinforced glass. This can be done with interior solar window film.
• A dull, softer “thud” sound suggests laminated or double-glazed glass, where the sound is absorbed by the air gap or plastic interlayer between panes. This needs exterior solar window film installation.
• A single-pane glass will sound thinner and more fragile — usually a lighter, higher-pitched tap.

Try tapping on different windows around your property.

• Sliding doors, patio doors, and balcony glass panels almost always use tempered or reinforced glass, which needs exterior film installation to prevent heat stress.
• Roof windows, skylights, or large façade windows are also likely to be toughened or laminated for safety reasons.
• Standard living room or bedroom windows are usually double-glazed and can often be safely fitted with interior window film.

Year-Round Comfort and Energy Savings.

Solar window film is not just for summer — it also helps during the cooler months. In winter, the same film reflects heat energy back into your home, helping retain warmth and improving insulation. This means your house stays more comfortable all year long — while saving on heating and cooling costs.

In short:

• Summer: Keeps heat out.
• Winter: Keeps warmth in.
• All year: Keeps energy bills low.

Perfect for Homes, Villas & Apartments.

Whether you live in a sunny seaside apartment or a countryside villa, window film helps you maintain comfort and privacy. Home applications include:

• Large living room or panoramic windows.
• Sliding doors and terrace glass.
• Conservatories and sunrooms.
• Skylights and roof glass.
• Bedroom and bathroom windows.

With clear, tinted, or reflective options, we can help you choose the perfect film to match your home's look and your comfort needs.

Ideal for Offices & Businesses.

Solar window film is one of the simplest ways to improve workplace comfort and productivity.

• Keeps offices cooler and more comfortable.
• Reduces glare on computer screens.
• Protects furnishings and merchandise from fading.
• Enhances your building's appearance with a professional finish.

For restaurants, hotels, and retail shops, solar film also helps maintain a pleasant atmosphere for customers — especially in spaces with large windows or glass façades.

How Solar Window Film Works.

Our high-performance films are made with multiple micro-thin layers that selectively reflect infrared and ultraviolet light while letting visible light pass through. When sunlight hits the window:

• Infrared heat is reflected away.
• UV rays are blocked before they enter.
• Visible light passes through naturally.

The result? Cooler, brighter, more comfortable interiors — without changing your view or your glass.

Trusted Experience Since 1973

Solar Window Film Spain is part of the Out of the Sun Group, originally founded in the Netherlands in 1973. With over 50 years of experience and a 5-star reputation, we guarantee professional installation, punctual service, and lasting performance.

✅ Reliable, on time, and always respectful of your home

✅ Only premium films — imported from California, USA

✅ Transparent pricing — no surprises

✅ Excellent after-sales support

⭐ 5-Star Google Reviews & Proven Portfolio – Trusted by Homeowners and Businesses Across Spain

At Out of the Sun – Solar Window Film Spain, our reputation speaks for itself. With a 5-star Google rating, we are proud to be the top-rated window film company in southern Spain, trusted by homeowners, villa owners, and commercial property managers alike. Our satisfied clients consistently praise our professional installation, premium-quality films, and outstanding customer service.

Solar Window Film Spain — keeping your windows clear, cool & comfortable since 1973.