Are Conservatories Cold in Winter? How to Fix Temperature Problems
Complete guide to conservatory temperature control: winter warmth, summer cooling, and the glass that solves both.
Get a fixed-price quote →❄️☀️ The short answer
No, a modern conservatory does not have to be too hot or too cold. With the right glass (low U‑value, solar control), proper insulation, and simple temperature control measures, you can enjoy your conservatory comfortably all year round. Standard double glazing may struggle – but advanced glass like New Generation Glass solves both winter chill and summer overheating.
❄️ How to Keep a Conservatory Warm in Winter
A cold conservatory in winter is usually caused by heat escaping through the glass roof and walls. Standard double glazing has a U‑value around 2.7 W/m²K – meaning significant heat loss. Here are the most effective solutions.
🔥 Top 5 winter warmth solutions
- Upgrade to low U‑value glass (≤1.2 W/m²K) – Reduces heat loss by up to 40% compared to standard double glazing. New Generation Glass achieves U‑value 1.1, matching a modern cavity wall.
- Install underfloor heating – Evenly distributes heat without taking up wall space. Budget £1,500–£3,000.
- Use thermal blinds or curtains – Roof blinds with reflective backing cut heat loss through glass by 25–30%.
- Check for draughts – Seal gaps around windows, doors, and the roof eaves. Often overlooked but makes a big difference.
- Consider a solid roof replacement – If you want to convert to a garden room, replacing the glass roof with an insulated tiled roof eliminates most heat loss. Budget £8k–£15k.
☀️ Hot Conservatory Solutions – Keeping Cool in Summer
Overheating happens when too much solar radiation passes through the glass. Standard glass lets in up to 80% of solar heat. Modern solar control glass reflects over 70% of solar energy while still letting in natural light.
Comparison: Standard glass vs New Generation Glass
| Feature | Standard double glazing | New Generation Glass |
|---|---|---|
| U‑value (heat loss) | 2.7 W/m²K | 1.1 W/m²K – 40% better |
| Solar heat gain (SHGC) | 0.78 (78% heat enters) | ≤0.35 – 70% reflection |
| UV protection | Partial | >99% UV block |
| Self-cleaning | No | Yes – photocatalytic coating |
| Glare reduction | None | Reflective layer reduces glare without tint |
Other summer cooling tips: External blinds or awnings (most effective as they stop heat before it enters), roof vents for hot air escape, ceiling fans, and planting deciduous trees for natural shade. But glass performance is the foundation – without solar control glass, you’ll always be fighting the problem.
🌡️ Conservatory Temperature Control – The Complete Guide
To achieve year‑round comfort, you need a system that works for all seasons. Start with the glass, then layer additional measures.
📋 The 3‑layer temperature control strategy
Layer 1: High‑performance glass – This is non‑negotiable. New Generation Glass combines low U‑value (1.1) with solar control (SHGC ≤0.35) and self‑cleaning. It’s designed specifically for the British climate where winters are cold and summers increasingly hot.
Layer 2: Passive measures – Roof blinds, window films, and thermal curtains provide extra buffering. External blinds are best for summer.
Layer 3: Active systems – Underfloor heating (winter) and ceiling fans or air conditioning (summer) for extreme days.
📊 Before & after: Real conservatory data (Room Outside client, Surrey)
Conservatory size: 4m x 4m, south‑west facing, glass roof & walls.
Previous glass: Standard double glazing (2010 install).
Upgraded to: New Generation Glass (March 2025).
- Winter temperature (no heating): Before – 8°C on a 2°C day → After – 16°C (8°C warmer).
- Summer peak temperature (July 2025, 30°C outside): Before – 42°C → After – 26°C (16°C cooler).
- Heating energy use (Dec–Feb): Before – 1,200 kWh → After – 680 kWh (43% reduction).
- U‑value improvement: 2.7 → 1.1 W/m²K.
Result: The conservatory is now used every day of the year, including as a home office in winter and a dining area in summer.
✨ New Generation Glass – Exclusive to Room Outside
Room Outside introduced the first Wonderglass™ in the UK in 1999. Today, our New Generation Glass (NGG) is the most advanced conservatory glass available for British homes.
- ✔️ Ultra‑low U‑value 1.1 – better than building regs for walls
- ✔️ Solar heat gain coefficient ≤0.35 – reflects 70%+ of summer heat
- ✔️ >99% UV protection – stops fading of furniture and flooring
- ✔️ Self‑cleaning coating – breaks down dirt with sunlight
- ✔️ No tint or darkened appearance – natural light all year
Read more about New Generation Glass → (Our dedicated glass page has 16,179 impressions – see the technical specs and test data.)
🛠️ Other quick fixes for temperature problems
For winter cold
- Add a thick rug to insulate the floor
- Seal gaps around door frames
- Install a ceiling fan on reverse (pushes warm air down)
- Use a portable oil‑filled radiator (cheap to run)
For summer heat
- Open roof vents and use cross‑ventilation
- Install external blinds or awnings (best)
- Use a portable air conditioner for peak days
- Add shade plants or external planting
Ready to fix your conservatory temperature problems?
We can assess your current conservatory, recommend the right glass, and provide a fixed‑price quote – no obligation.
Speak to a temperature specialist →📞 Call David on 01243 538999 – we’ll explain glass options simply.
❓ Frequently asked questions
Are conservatories cold in winter?
Basic conservatories with standard double glazing can be cold (as low as 5–10°C on a freezing day). But with low U‑value glass (≤1.2) like New Generation Glass, they stay warm without excessive heating – often 16°C on a 2°C day with no active heating.
How can I keep my conservatory warm in winter?
Best solution: upgrade to low U‑value glass (≤1.2). Add underfloor heating, thermal blinds, and check for draughts. New Generation Glass reduces heat loss by 40% compared to standard double glazing.
What is the best glass to stop conservatory overheating in summer?
Solar control glass with low solar heat gain coefficient (SHGC ≤0.35). New Generation Glass reflects over 70% of solar radiation while maintaining natural light – standard glass lets in 78% of heat.
What is New Generation Glass?
Room Outside’s exclusive advanced glass: U‑value 1.1, SHGC ≤0.35, >99% UV block, self‑cleaning. Designed for the British climate. It keeps conservatories warm in winter (low heat loss) and cool in summer (high solar reflection).
Will adding blinds help with conservatory temperature?
Yes – thermal roof blinds reduce heat loss by 25–30% in winter and block up to 40% of solar gain in summer. But glass performance is the foundation. New Generation Glass works even without blinds.
How much does New Generation Glass cost?
Typically 20–30% more than standard double glazing, but the energy savings (30–40% lower heating bills) and year‑round usability make it cost‑effective. Contact us for a project‑specific quote.
Enjoy your conservatory every day of the year
Stop worrying about being too hot or too cold. New Generation Glass makes year‑round comfort possible.
Request a glass consultation →🏆 Over 50 years of conservatory & glass extension expertise
