What Type of Glass Is Best for a Traditional Orangery?

Choosing the right glass is one of the most important decisions you’ll make when designing a traditional orangery. It affects how the space looks, feels, and performs, not just in summer but all year round.

At Glass House Architecture, we specialise in bespoke hardwood and oak orangeries for heritage homes, period properties, and classic country houses. In this article, I’ll walk you through the different types of glazing we use, what to consider, and how to strike the right balance between elegance and energy efficiency.

Why Glass Choice Matters

Many older conservatories are known for being freezing in winter and sweltering in summer. That’s usually down to poor insulation and single glazing. A traditional orangery, by contrast, is designed to be a real extension of your home - warm, light-filled, and usable all year.

That’s where modern glass technology makes a huge difference. While the structure may be classical, the glazing we use is anything but outdated.

Understanding U-values (In Simple Terms)

The U-value tells us how well a type of glass keeps heat in. The lower the number, the better the insulation. For example, a traditional single-glazed window might have a U-value of 5.7, while our advanced double glazing can reach 1.2 or even lower. Triple glazing or insulated roof glass can go below 1.0.

Better U-values mean more comfort, lower heating bills, and less condensation, all without changing the character of your home.

Glazing Options We Recommend

Here are the main types of glass we use when building traditional orangeries:

1. Advanced Double Glazing

This is our most popular option. It provides excellent thermal insulation, improved soundproofing, and a clear appearance that suits both modern and traditional builds. We often use it in timber or oak frames with sightlines designed to match period features.

2. Low-Iron Glass

Low-iron glass is brighter and clearer than standard float glass. It’s ideal when you want true clarity, especially in roof lanterns. We pair this with solar control coatings to help reduce glare and overheating.

3. Solar Control Glass

This glass includes an invisible coating that reflects excess heat from the sun while still letting in natural light. It’s especially helpful in south-facing orangeries. You can enjoy a warm winter room without it becoming an oven in July.

4. Self-Cleaning Glass

A clever option for roof lanterns and hard-to-reach panes. It uses a special coating that breaks down dirt when exposed to UV light and washes it away with rainwater. We often recommend it for clients who want to reduce maintenance.

5. Acoustic Glass

If your property is near a road or a busy area, acoustic glazing can help reduce outside noise. This type of glass works beautifully in traditional orangeries when peace and quiet are a priority.

6. Heritage-Style Double Glazing

For listed or conservation-area homes, we sometimes use thinner-profile double glazing with traditional-looking spacer bars and timber beads. It offers the energy efficiency of modern glass while maintaining a period look.

What About Triple Glazing?

Triple glazing offers even lower U-values than double glazing. It’s ideal for colder regions or homes that need extra insulation. That said, it’s heavier and more expensive, and it can reduce light slightly. We only use it where the structure can support it and where the client prioritises thermal performance above all.

Appearance and Proportions

The look of your glass matters as much as its performance. In period homes, we often use tall vertical panes arranged in traditional sash-style patterns. Georgian-style glazing bars can also be included if appropriate. Our goal is always to match the orangery’s appearance to the rest of your home.

That means getting the balance right between architectural features, modern comfort, and timeless design.

Roof Glazing for Orangeries

Most traditional orangeries include a solid flat roof with a central lantern. The glass used in that lantern needs to be tough, thermally efficient, and ideally self-cleaning. For these areas, we use laminated or toughened glass with solar control built in.

Some designs feature two lanterns or even corner sections. In every case, we carefully select the glass to reduce glare and control heat, without dimming the room.

Compared to Brick and Glass Box Extensions

Brick extensions feel more enclosed and insulated. Glass box extensions feel modern and open. A traditional orangery sits perfectly between the two, combining solid structure with bright glazing. With the right glass, it can outperform older brick builds on energy efficiency and offer more charm than a frameless cube.

Glass Costs and Value

The type of glass you choose can influence the overall cost of a traditional orangery, but it’s almost always worth the upgrade. High-performance glazing helps reduce running costs and makes the space genuinely usable. It also adds to the long-term value of the property.

Planning Permission and Building Regulations

While glazing itself doesn’t usually affect planning permission, some conservation areas do restrict visible finishes or reflective coatings. We can advise on what's suitable and prepare applications if needed.

All our glazing options meet or exceed current UK building regulations, and many surpass the minimum requirements.

Materials We Use with Glass

We pair our glass with timber, oak, or painted hardwood frames - never UPVC. This keeps the look in line with traditional architecture. Where needed, we can use brick plinths or stone cills to anchor the design and reflect the materials of the main property.

Pros and Cons of Glazing Types

• Double Glazing: Reliable, cost-effective, and clear

• Triple Glazing: Warmer but heavier and costlier

• Solar Glass: Excellent for sunny spots, but a little pricier

• Self-Cleaning: Low maintenance, best for roofs

• Acoustic Glass: Peace of mind for busy locations

We guide each client based on their lifestyle and location.

Common Mistakes to Avoid

A common mistake is choosing cheap glazing to save money up front. Poor-quality glass leads to overheating, draughts, and condensation. Another is over-glazing without proper shading or ventilation. We always factor in accessories like blinds and roof vents as part of the build.

A Note on Orangery Ideas

Glazing plays a key role in all types of orangery ideas, whether you're planning a kitchen extension, garden room, or formal lounge. The right glass makes the space liveable and beautiful.

Final Thoughts

At Glass House Architecture, we believe a traditional orangery should feel like it belongs to the home, not just in appearance, but in comfort. That’s why we take glazing seriously.

By choosing high-performance, heritage-appropriate glass, you get a space that’s elegant, warm, and ready for year-round use. Whether you're building something grand or modest, we’ll help you choose the best possible glazing for your lifestyle, location, and budget.