A Guide to Getting Glazing Right for Orangery Extensions

There’s a moment in most orangery projects where the conversation moves too quickly, the structure gets agreed, the roof lantern gets specified, and then the glazing gets treated as a detail to sort out later; something to match the budget as opposed to something that helps shape the experience. However, understanding the key features of orangery extensions—such as their unique blend of masonry and glass—can help ensure the design maximizes both style and function.

That’s the wrong order. The glazing in an orangery isn’t a finishing touch: it determines whether the space is genuinely usable on a January morning or uncomfortably hot by 3 O’Clock on a July afternoon. Get it right, and the orangery becomes a bright space that everyone gravitates to all year round, but get it wrong, and you’ll only use it in spring.

This guide covers what an orangery is, how it differs from a conservatory and a traditional extension, and most importantly, how to specify the glazing so the space actually performs the way it should.

An orangery is a type of single storey extension that sits between a conservatory and a traditional extension. It is characterized by its solid construction, featuring masonry walls, insulated columns, a solid perimeter flat roof, and glazed walls that maximize natural light and create a seamless connection with the outdoors. Key structural elements include one or more roof lanterns that draw daylight into the centre of the space, and an internal pelmet integrated within the roof design, which enhances both aesthetics and energy efficiency while providing a practical space for lighting or speakers.

The result is a room that feels substantially built, more connected to the house than a conservatory, with superior temperature control, privacy, and permanence of character. Orangeries typically feature a solid perimeter flat roof with one or more roof lanterns, while conservatories are defined by their fully glazed roofs and a higher proportion of glass in their overall construction. Unlike a conservatory, which is predominantly glass and can struggle with temperature extremes, a well-designed orangery manages heat and light more effectively because the glazing is considered in relation to solid construction rather than instead of it. Modern orangery designs also utilize advanced glazing techniques for improved energy efficiency, creating a bright living space that can be enjoyed year-round.

That balance between masonry and glass is what defines an orangery, and it’s also what makes the glazing specification so consequential. Orangeries are often used as open-plan kitchen-diners, dining areas, or kitchen extensions, providing additional space for living, entertaining, and enhancing the functionality of a home. Their solid construction means building regulations are stricter than for conservatories, reflecting their more structural nature. Permitted development rights stipulate that an orangery extension must not exceed 50% of the total area of land around the original house as of July 1, 1948; exceeding this requires planning permission and consultation with the local planning authority. A well-designed orangery is viewed as a permanent extension and can add significant value to a property—sometimes up to 10% of the overall value.

Orangery extensions come in a variety of styles, each designed to suit different tastes, budgets, and property types. The traditional orangery is a classic choice, featuring solid brick pillars, a decorative cornice, and a partially glazed roof. This style is ideal for those looking to create an airy feel that blends harmoniously with the existing architecture of a period property or original house. The combination of masonry and glass not only enhances the building’s character but also ensures compliance with building regulations and delivers excellent energy efficiency.

For those seeking a more contemporary look, the modern orangery offers a striking alternative. With its flat roof, expansive glass walls, and minimalist lines, a modern orangery maximises natural light and creates a seamless connection between indoor and outdoor spaces. This style is particularly popular for kitchen orangery extensions and open-plan living spaces, where abundant natural light and a strong visual link to the garden are key priorities.

Bespoke orangeries provide the flexibility to tailor every aspect of the extension to your specific needs, whether that means integrating unique design features, maximising space, or achieving a particular architectural style. For homeowners looking for a more cost-effective solution, garden rooms offer many of the same benefits as a traditional orangery but with a simpler structure and lower build costs.

When planning any orangery extension, it’s essential to consider factors such as energy efficiency, compliance with building regulations, and whether you’ll need planning permission. By carefully selecting the right style and features for your project, you can create a bright, welcoming space that enhances your home and garden for years to come.

Most orangery extensions fall under permitted development rights, which means that you don’t need a full planning application, although a lawful development certificate is still required and takes approximately eight weeks to obtain. However, you will need to obtain planning permission if the property is listed, sits within a conservation area, is a flat or maisonette, or if the proposed structure exceeds permitted development size limits.

When planning your orangery, it’s important that the design complements the existing property, ensuring seamless integration with the current architecture and surrounding environment. For detached houses, the rear extension cannot project more than four metres beyond the original rear wall under standard permitted development, though this can be extended to eight metres under the prior approval route, which requires neighbour consultation.

Orangery kitchen extensions are a popular option, blending indoor and outdoor living, but may require planning permission, especially if they exceed size limits or are located in sensitive areas. Building regulations apply to all orangeries, unlike conservatories, which can be exempt if they meet specific criteria around size and thermal separation. This is because orangeries are classified as a single-story extension and therefore must meet standards covering structure, insulation, ventilation and energy efficiency.

This is worth knowing early, as it means your glazing specification needs to comply with Part L of the Building Regulations, which sets requirements for both heat loss (U-value) and solar gain (G-value).

Extending a listed building or a property within a conservation area presents unique challenges, especially when planning an orangery extension. In these cases, obtaining planning permission is often more complex, as the local planning authority will scrutinise the design to ensure it respects the building’s heritage and existing architecture. Working with professionals experienced in listed buildings is essential—they can help navigate building regulations and develop a bespoke orangery design that complements the period style of your property.

A sensitive approach to orangery design is crucial. This means using traditional materials, preserving original features, and ensuring that the new extension does not overpower or detract from the character of the main house. The goal is to create an orangery that feels like a natural extension of the property, enhancing its value and appeal while meeting all regulatory requirements.

By collaborating with experts and prioritising thoughtful design, it’s possible to create a stunning new space that both celebrates and preserves the unique qualities of your listed building. This careful balance ensures your orangery extension not only meets planning and building regulations but also stands the test of time as a valuable addition to your home.

The Roof Lantern

The roof lantern is the defining element of most orangeries and the glazing decision with the biggest impact on how the space feels and performs. Choosing a glass roof for your orangery roof lantern not only floods the centre of the room with daylight from above, but also enhances energy efficiency and aesthetic appeal. This natural light is genuinely unlike light from any other source. It’s also the element most at risk of overheating, because a south or west-facing roof receives direct solar radiation at the highest angles during summer.

The solution isn’t to minimise the lantern or add external louvres as an afterthought. It’s to specify the glass correctly from the outset, as a solar control coating on roof lanterns can significantly reduce heat gain while maintaining light transmission, keeping the space bright without being uncomfortable. Combined with an opening section for ventilation, this approach manages the thermal environment without compromising the architecture.

For those seeking proven quality, the Ultraframe Glass Roof system is a leading choice, having been installed over 1.5 million times and standing as the only glass conservatory roof system to hold BBA approval, ensuring high standards in construction materials.

We’ve worked on orangery projects where the roof lantern specification was the starting point of everything else, with all subsequent glazing decisions referenced back to it, and in our experience, that’s the right approach.

Sliding and Bifold Doors

The connection between an orangery and the garden is one of the most defining qualities, and the doors that create the connection need to work thermally and acoustically as well as architecturally, particularly in the UK climate, where it will be closed for the majority of the year. Incorporating glazed walls in orangery extensions enhances this seamless, open feel and maximizes views, creating a strong visual connection with the garden.

Sliding glass doors offer a cleaner aesthetic solution in most orangery settings. The frames are slimmer, the sightlines are better, and when they open, they create a wider, more generous threshold to the garden than biofold alternatives. For an orangery where the interior design is considered, and the garden view matters, the frame profile of the door deserves the same attention as the glass itself.

On the thermal side, doors in an orangery need to perform well on both the G-value and U-value. A west-facing set of sliding doors can receive a significant afternoon sun in summer, so specifying the lower G-value coating on those doors, while using a higher G-value on north-facing windows, gives the room the ability to passively regulate the temperature rather than fighting against it.

Side Windows and Fixed Panels

Where glazing appears in the walls of an orangery, whether in windows, fixed panels or full-height sections, the specification should follow the same logic as the doors and lantern. Orientation matters here just as much as it does with everything else. South and west-facing wall glazing benefits from solar control, north-facing glazing benefits from low-iron glass and a low e-coating that maximises light transmissions while reflecting heat back into the room.

Treating every elevation identically is one of the most common glazing specification mistakes we encounter, and it’s straightforwardly avoided with a considered approach from the start of the project. Window height is also worth thinking about in an orangery context, because higher windows distribute light more evenly across the space and complement the overhead light from the roof lantern, while lower windows direct warmth and views to seated height, which suits a kitchen or dining use. This is especially important in a small orangery, where maximizing natural light and usability is crucial for creating a bright, open, and functional space. Proper glazing and thoughtful design choices not only enhance light but also contribute to year round comfort by improving insulation and maintaining a pleasant environment regardless of the season. Additionally, designing an orangery with two roof lanterns can introduce a unique architectural element, optimizing natural light and adding a sense of balance and symmetry to the space.

The orangeries that feel genuinely comfortable across all seasons tend to share a few things in common. The glazing specification responds to orientation rather than applying a single product across all elevations, which helps enhance both the functionality and aesthetic appeal of the orangery. The roof lantern has solar control and an opening section for ventilation. The doors have the right balance of G-value and U-value for the direction they face, and the overall design has been considered as a system rather than a collection of individual components.

A well-designed orangery provides additional space for living, dining, or entertaining, making it a valuable extension to your home. It is important to maintain the same quality in glazing and construction across all orangery projects to ensure lasting value and consistent standards.

When these things are in place, an orangery doesn’t rely on air conditioning in summer or a dedicated heating system running hard in winter. The space manages its own temperature more naturally, cooler in summer because the solar load is controlled, and warmer in winter because the glazing is retaining heat rather than shedding it. This is what distinguishes a well-specified orangery from one that looks right on the day it’s completed but proves frustrating to live with over time.

We work on orangery projects at the glazing specification stage, alongside architects, kitchen designers and homeowners who want the glass to perform as well as it looks. Many clients are now choosing a kitchen orangery extension as a popular way to create additional space and improve the functionality of their home, seamlessly integrating the kitchen with outdoor views and natural light. That means discussing roof lantern options and solar control glazing early in the process, not as an upgrade to consider at the end. It means recommending different specifications for different elevations when that’s the right call, and it means understanding how the space is intended to be used and letting that inform the choices.

If you’re designing an orangery and want to talk through the glazing before decisions are locked in, get in touch with the team. You are also welcome to visit our showroom in Watford to see our systems in person and discuss your project with us directly.

A successful orangery extension project starts with thorough planning and a clear understanding of your existing property’s architectural style and features. The initial assessment should consider how the new orangery will interact with both indoor and outdoor spaces, ensuring that the design maximises natural light and creates a harmonious flow between the house and garden. Energy efficiency and compliance with building regulations should be at the forefront of every decision, from glazing options to insulation and ventilation.

Once the design concept is finalised, the next step is to obtain any necessary planning permissions and ensure all building regulations are met. This stage is crucial for avoiding delays and ensuring the project runs smoothly. With approvals in place, construction can begin, transforming your vision into reality.

Throughout the build, regular communication between the homeowner, designer, and builder is key to maintaining quality and ensuring the finished orangery meets your expectations. Attention to detail, skilled craftsmanship, and a focus on lasting value will result in a bright, functional, and beautiful extension that enhances your property and provides significant value for years to come. By investing in careful planning and expert execution, you can create an orangery that truly elevates your living space and connects your home to the outdoors.