Timber - PVC - Aluminium - Windows, Doors & Conservatories in Hampshire
Beating the Heat: The Complete Guide to Solar Control Glass
Beating the Heat: The Complete Guide to Solar Control Glass
Category: Glazing Guide / Home Comfort
Reading Time: 7 Minutes
📌 Key Takeaways
- The “Greenhouse Effect”: Standard glass traps solar heat inside, causing conservatories to overheat rapidly in summer.
- How it Works: Solar control glass features a special coating that reflects heat back outside before it enters the room.
- More Than Just Heat: It also significantly reduces glare for watching TV and blocks UV rays that fade furniture.
- All-Year Comfort: Modern units combine Solar Control (outer pane) with Low-E (inner pane) to keep you warm in winter too.
We all love a bright, sunny room—until it becomes a greenhouse. If you have a conservatory or a large south-facing window, you know the struggle: freezing in winter, boiling in summer.
Historically, the only solutions were expensive air conditioning or dark tinted films. Fortunately, modern glazing technology offers a far better solution: Solar Control Glass.
In this guide, KJM Group explains how this intelligent glass works to keep your home cool, comfortable, and bright, even during a heatwave.
Table of Contents
1. What is Solar Control Glass?
Solar control glass is a high-performance glazing product designed specifically to minimise the amount of solar heat entering a building. Unlike older, heavily tinted glass that simply absorbed heat and blocked light, modern solar control glass uses advanced engineering to filter sunlight intelligently.
It allows natural daylight to pass through while reflecting and absorbing a significant portion of the sun’s infrared radiation (the invisible part of the spectrum that carries heat).
🔬 How the Coating Works
This performance is achieved through a microscopic, transparent metallic coating applied to the glass during manufacture. This coating acts like an invisible shield. When the sun’s rays hit the window, the coating reflects the heat energy back outside, preventing it from building up inside the room.
2. The Key Benefits for Your Home
Installing solar control glass, particularly in a conservatory roof or large bi-folding doors, transforms the usability of the space.
- Cooler Summer Temperatures: The primary benefit. By rejecting solar heat, the room remains at a much more comfortable temperature during hot weather, reducing the need for fans or air conditioning.
- Reduced Glare: Bright sunlight can make reading, working on a laptop, or watching television difficult. Solar control glass softens harsh light, reducing eye strain without making the room dark.
- UV Protection: The sun’s ultraviolet (UV) rays are responsible for fading fabrics, flooring, and furniture. High-quality solar control glass blocks a high percentage of harmful UV radiation, protecting your interior furnishings.
3. Understanding the Jargon: The “g-value”
When comparing different glass types, you might see technical terms. The most important one for overheating is the g-value (also known as the Solar Factor).
The g-value measures how much total solar heat enters a room through the glass. It is expressed as a number between 0 and 1.
💡 The Rule of Thumb
The lower the g-value, the better the glass is at stopping heat.
- Standard Uncoated Glass: Has a high g-value (approx. 0.75 to 0.85), meaning 75-85% of the sun’s heat gets in.
- Solar Control Glass: Can have a g-value as low as 0.40 or even 0.25, meaning it blocks a massive amount of incoming heat.
4. The Perfect Combination: An All-Year-Round Solution
A common worry is that glass designed to keep heat out in summer might make a room freezing cold in winter.
However, modern double-glazed units are smart. We combine an outer pane of Solar Control glass with an inner pane of Low-E (thermal insulating) glass.
This creates the perfect dual-action unit: the outer pane reflects the sun’s intense heat in summer, while the inner pane reflects your home’s heating back into the room during winter. This ensures a conservatory or extension is a comfortable living space all year round.
Frequently Asked Questions
Modern solar control glass is very neutral. While some high-performance options for conservatory roofs might have a subtle blue or neutral tint to maximize heat rejection, glass for side windows and doors is virtually clear, maintaining natural light levels.
It is essential for conservatory and orangery roofs, which are the biggest cause of overheating. It is also highly recommended for large glazed areas like bi-fold or sliding patio doors, especially if they face south or south-west.
Yes. You don’t need to replace your entire window frames. We can simply replace the existing sealed double-glazed units with new, high-performance solar control units, instantly upgrading the comfort of the room. Contact us for a quote.
Keep Your Home Cool This Summer
Don't let the sun make your favourite room unusable. Upgrade to intelligent glazing.
Visit our Andover Showroom to see the difference between standard and solar control glass for yourself.
📚 Explore Our Comprehensive Glass Guides
Choosing the right glass is essential for your home's comfort and security. Ensure you have the full picture with our series of expert guides:
🚀 The Ultimate Guide to All Window Glass Types
- ☀️ Energy Efficiency: The Comprehensive Guide to Low-E Glass
- 🛡️ Safety Standards: The Ultimate Guide to Toughened Glass
- 🔒 Security & Silence: Laminated Glass Benefits Explained
- 💎 Crystal Clear Views: Low-Iron Glass (Optiwhite) Explained
- ✨ Low Maintenance: The Truth About Self-Cleaning Glass
- 👁️ Privacy & Style: Guide to Obscure & Textured Glass
Mark Pearce is a highly experienced specialist in the double glazing industry, having built his knowledge from the ground up through hands-on experience in installation, manufacturing, sales, and business management. Beyond his role at KJM, Mark is a keen blogger, writer, and traveller, often sharing insights on the latest innovations in the home improvement industry.
- KJM Update: How We Are Closing the Loop on Window Scrappage - 19 November 2025
- KJM Group MD Attends House of Commons Event to Champion UK Glass Industry - 14 November 2025
- Industry News Alert: Pilkington Discontinues Classic Flemish Glass - 14 November 2025
