Does a Glass Roof Make Your Conservatory Too Hot?
Stop your beautiful glass room from becoming an unusable summer greenhouse. Discover the technology that keeps your conservatory comfortable all year round.
Quick Answer: Does a Glass Roof Have to Overheat?
No. A full glass roof doesn’t have to make your conservatory unbearably hot. The issue isn’t glass itself, but the type of glass used. Standard conservatory glass acts like a greenhouse, trapping heat. New Generation Glass uses advanced technology to reflect 86% of solar heat while maintaining crystal-clear views. You don’t need to compromise with polycarbonate or solid roofs that ruin the glass room experience.
The Real Problem: Why Your Conservatory Overheats
Conservatories overheat due to uncontrolled solar gain—a process where sunlight passes through ordinary glass and converts to heat that gets trapped inside. This isn’t just about air temperature; it’s about thermal radiation that heats up surfaces, furniture, and creates an environment that’s physically uncomfortable to be in.
With Ordinary Glass
On a typical British summer day (28°C outside), ordinary glass allows infrared radiation to flood in, turning your conservatory into:
- An unusable space for 4-5 months each year
- A furnace that damages furniture and fabrics
- An energy drain if you try to cool it with AC
- A wasted investment in your home
With New Generation Glass
The same summer day becomes perfectly comfortable with technology that:
- Reflects 86% of solar heat before it enters
- Maintains bright, clear views without tinting
- Creates a usable space year-round
- Protects furnishings from UV damage
📊 The Physics of the Problem
Solar radiation consists of three components: visible light (what we see), ultraviolet (causes fading), and infrared (carries heat). Standard glass blocks most UV but transmits most visible light AND infrared. The infrared radiation gets absorbed by interior surfaces, which then re-radiate heat at longer wavelengths that cannot escape back through the glass—this is the greenhouse effect in action.
The Flawed Compromises You Should Avoid
For years, conservatory companies have offered solutions that “solve” the overheating problem by compromising on the very thing you wanted: a beautiful glass room.
Polycarbonate Roofing
Plastic sheets with air gaps
- Severely distorts light and view
- Creates dim, industrial appearance
- Reduces some heat
- Better for carports, not premium conservatories
Tiled/Solid Roof
Traditional roofing materials
- Destroys connection to outdoors
- Loses the airy, light-filled feel
- Cuts heat build-up
- Turns conservatory into standard extension
Tinted/Reflective Glass
Applied films or body-tinted glass
- Noticeable colour cast (bronze/blue)
- Reduces visible light transmission
- Some heat reduction
- Alters interior/exterior appearance
New Generation Glass
Advanced solar control technology
- Crystal clear, no tint or distortion
- Reflects 86% of solar heat
- Maintains bright, natural light
- True glass conservatory experience
The fundamental issue with all compromise solutions is they treat the symptom by removing or altering the cause—the glass itself. At Room Outside, we believe the better approach is to enhance the glass’s performance, allowing you to enjoy the full aesthetic benefit without thermal penalty.
How New Generation Glass Actually Works
Unlike standard double glazing that simply slows heat transfer, New Generation Glass uses spectrally selective coatings—microscopic layers that act like a ‘smart filter’. They allow visible light to pass through (keeping your room bright) while reflecting 86% of infrared heat before it even enters your space.
The Technology Behind the Comfort
Solar Control Coating
A microscopically thin metallic layer applied via magnetron sputtering technology that reflects infrared heat while transmitting visible light.
Low-E Coating
Facing the interior, this coating reflects long-wave radiant heat back into the room during winter while allowing beneficial solar gain.
Argon Gas Fill
Inert, dense argon gas between panes (34% better insulation than air) significantly slows heat transfer in both directions.
Warm-Edge Spacers
Thermally broken composite materials eliminate cold bridges at glass edges, reducing condensation and improving overall U-value.
🇬🇧 Engineered for British Weather
New Generation Glass wasn’t developed in a laboratory vacuum. It was engineered through real-world testing across hundreds of installations in the South East. We’ve specifically addressed the unique challenges of British weather:
- Variable Season Performance: Works efficiently whether it’s 30°C in July or -2°C in January
- Humidity Control: Warm-edge technology reduces condensation that plagues many conservatories
- Low-Light Efficiency: Maintains thermal performance even on cloudy days
- Durability: Withstands British weather extremes without degradation
Real Results: The Henderson Family, Surrey
From Unusable to Year-Round Living Space
The Henderson family’s south-facing conservatory had become a “no-go zone” from May to September, with temperatures regularly hitting 42°C on summer afternoons. They were considering replacing it entirely with a solid extension until they discovered New Generation Glass.
After upgrading their roof glass, the transformation was immediate. On the same August afternoon that previously reached 42°C, their conservatory now stabilises at a comfortable 26°C. The space has become their favourite room for morning coffee, afternoon reading, and evening relaxation—truly usable year-round.
The Room Outside Advantage: Why We’re Different
🌟 Pioneers in Glass Technology
We were the first in the UK to introduce the revolutionary Wonderglass™ from Four Seasons Sunrooms in 1999. This wasn’t merely a product launch; it was a paradigm shift that proved a glass roof could be thermally competent without compromising on aesthetics.
Since then, our New Generation Glass has evolved through two decades of refinement, specifically for the unique challenges of the British climate. It represents the culmination of 50+ years of experience creating beautiful, comfortable glass extensions across Kent, Surrey, Sussex, and beyond.
What New Generation Glass Offers You
Unmatched Solar Control
Reflects up to 86% of the sun’s rays, reducing heat build-up to keep spaces 10-15°C cooler than with standard glass.
Outstanding Thermal Performance
Exceptionally low U-value (under 1.0 W/m²K) helps retain warmth in winter, reducing heating costs.
Advanced Insulation
Warm edge technology and argon gas filling boost overall efficiency beyond standard double glazing.
Superior UV Protection
Blocks virtually all harmful UV rays, protecting your furniture, artwork, and fabrics from fading.
Crystal Clear Views
No tint or colour distortion—just bright, natural light and perfect visibility of your garden.
Return on Investment
Transforms your conservatory from seasonal to year-round use, adding real value to your home.
Your Potential Savings & Benefits
Stop Compromising on Your Dream Conservatory
Book your no-obligation thermal assessment today and discover how New Generation Glass can transform your space from a summer greenhouse to a year-round living area.
See the Proof
Watch our radiometer heat demonstration that visually shows the dramatic difference.
Get Precise Analysis
Receive a tailored temperature assessment for your specific conservatory.
Limited Availability
Summer assessment slots are filling fast—book before the next heatwave.
Sources & Technical References
Glass and Glazing Federation: Technical Standards for Thermal Performance; Building Research Establishment: UK Climate Data for Building Design; Chartered Institute of Building Services Engineers: Guide to Solar Gain Management; Room Outside Laboratory: Comparative Thermal Testing Data 2015-2024; Four Seasons Sunrooms: Wonderglass™ Technical Specifications 1999; Room Outside Customer Satisfaction Surveys 2020-2024.
Frequently Asked Questions
Does New Generation Glass look different or tinted?
Not at all. The advanced solar control and low-emissivity coatings are almost completely invisible to the naked eye. Your views remain stunningly clear, bright, and neutral, without the green or blue tinge of older coated glasses.
Can my existing overheated conservatory be upgraded?
Yes. We regularly retrofit older conservatories with New Generation Glass. The transformation is often described by clients as ‘like gaining a completely new room.’ We conduct a full survey first to ensure compatibility with your existing framework.
How does it work in winter to keep heat in?
The low-emissivity (Low-E) coatings reflect interior heat back into the room while still allowing visible light to pass through. Combined with argon gas filling and warm-edge spacers, this creates a thermal barrier that significantly reduces heat loss with a U-value of less than 1.0 W/m²K.
Is this just expensive double glazing?
No, it’s fundamentally different technology. While standard double glazing simply slows heat transfer, New Generation Glass uses spectrally selective coatings that act like a ‘smart filter,’ allowing visible light through while reflecting 86% of infrared heat before it enters your space.
What about condensation issues in winter?
New Generation Glass significantly reduces condensation through its warm-edge spacer technology and overall improved thermal performance. By keeping the interior glass surface warmer, there’s less temperature difference between the glass and room air, which minimises condensation formation.
How long do the coatings and performance last?
The coatings are permanently bonded to the glass at a molecular level during manufacturing and located inside the sealed glass unit where they’re protected from weather, cleaning, and physical contact. They will last the lifetime of the glass unit itself—typically 20+ years—without degradation of performance.
Does it work for all conservatory orientations?
Yes, but the benefits are most pronounced for south and west-facing conservatories that receive the most direct sunlight. East-facing rooms benefit from morning sun control, while north-facing rooms still gain from the superior insulation properties in winter.
Is there a visible demonstration of the heat control properties?
Absolutely. We have a “tunnel of heat” demonstration using radiometers that visually shows the dramatic difference in heat transmission between standard glass and New Generation Glass. You can see this demonstration in our showroom or during a consultation.
Questions about preventing conservatory overheating? Call our technical team on 01243 538999 or send us a message
Experience the Difference for Yourself
Don’t compromise on your dream of a beautiful, comfortable glass conservatory. See how New Generation Glass can transform your space into a year-round living area you’ll actually use and enjoy. Book a consultation to experience our thermal demonstration and receive expert advice tailored to your specific conservatory.
Room Outside: Creating comfortable, beautiful glass extensions since 1973.
Serving Kent, Surrey, Sussex, Hampshire, London and across the South East.
