What is the Difference Between a Glass Extension and a Conservatory

Understanding the technical, aesthetic and legal differences between a glass extension, orangery and conservatory.

When considering a beautiful glass room, or a glass orangery, one of the most common questions people ask is how they differ from a standard conservatory. Certainly, there are plenty of similarities; both provide a bridge between indoor and outdoor living, allowing you plenty of natural light while protecting you from the elements. They both act as an additional space to a building; so what is the actual difference between all the different options?

What is a Conservatory?

A conservatory is an additional structure attached to a building or home that is most often made largely of glass. The key definition of a conservatory is that it is thermally separated from the existing house, that means that thermally efficient doors and walls are maintained between the conservatory and the rest of the building.

This distinction allows conservatory extensions to have slightly different performance requirements under Building Regulations or other local building codes. The thermal performance requirements for a conservatory will differ depending on the region and country of the building however,

The traditional design for a conservatory is an angled roof with uPVC framing which holds glass units. However, you don’t have to stick with the traditional designs for conservatories.

Using structural glass or modern architectural glazing can be a great way to create a modern design for your conservatory.

What is the difference between a conservatory and a sunroom?

The term ‘sunroom’ is often just used as another name for a conservatory. These highly glazed building additions are specifically located on a building to capture the sun, using the heat from the sun to warm the internal space.

Building Regulations for a Conservatory

In most cases, you don’t need planning permission for a conservatory. You won’t need building regulations approval if:

The conservatory is on the ground level and covers less than 30 square metres in total
It has an independent heating system and separate temperature controls
Glazing and electrical installations follow all applicable building regulations and requirements.

Building regulations and building codes are very often updated so it is important to check the latest updates and talk to a professional before starting on a build.

Design Options for a Conservatory

If you opt for a conservatory that does not mean you cannot create a bespoke design. At IQ Glass, we have created a large range of conservatories for luxury houses over our many years. See below for some examples.

In Ascot, we created this double height structural glass conservatory for a classic white neoclassical house.
In Hampstead, this glass conservatory was created with a sleek, all glass exterior.
This completely bespoke glass conservatory was created in a gothic style to match the design of the existing house.

What is a Glass Extension?

A glass or glazed extension is a true building extension that features glazing as a key element of its design.

An extension – whether a glass extension or using more opaque materials – is open to the existing building, changing the location of the external thermal envelope. This means that the thermal requirements of a glass extension are much higher than that of a glass conservatory. Double glazing must be used as a minimum with triple glazing fast becoming the most popular option for additional thermal insulation. Any solid structures must also be fully insulated and built in accordance with Building Regulations or local codes.

Glass extensions can be added to a building at the rear, on the roof or at the side – essentially anywhere you want to add more space.

Design Options for Glass Extensions

The design options for glass extensions are almost endless. Glass is a unique material, bringing together transparency, strength and performance into one material.

In London, we created a unique glass extension that spanned two floors using a combination of structural glass and slim sliding glass doors beneath a solid roof.
In York, we created an industrial style glass extension using steel look, aluminium windows and doors.
In Lyme Regis, this glass extension to a Grade II listed building had a frameless, sloped glass roof and acted as a glass link between the listed home and the modern addition.
In Manhattan, this double height glass extension combined slim sliding doors with a structural glass roof to create a glass extension in New York.
A classical steel framed glass extension was chosen for this listed house in Chelsea, using the thermally broken Mondrian steel windows and doors.

You can learn more about how a glass extension design comes together here in our technical article: The Anatomy of a Glass Box Extension.

What Doors Can I Use in a Glass Extension?

The most minimal design for a glass extension can be achieved with slim sliding doors as these have sightlines from 21mm. Slim sliding doors are by far the most popular choice for a modern glass extension.

This farmhouse created a glass extension using slim framed sliding doors across all three walls.

But slim sliding doors are not the only option!

At this glass extension in Northamptonshire we integrated an aluminium casement door into the double height glass extension.
You can create a glass extension with bifold doors like we did here in London.
This private home in London used thermally broken steel doors with a steel supported glass roof to create a timeless design.
Or why not do something different and use oversized pivoting doors to create a contemporary rear glass extension like we did here in Shoreditch.

Explore our selection of completed glazed extension projects here.

Planning Permission for Glass Extensions

Your architect will be able to advise you on whether your intended glass extension requires planning permission. This often depends on the local authority rules as well as the size of the glass extension you are looking to add.

Read more here: Will I need Planning Permission?

What is an Orangery?

Rather than technical and legal distinctions, an orangery is more often used to refer to a style or design of glass extension.

Orangeries get their name from the historical glass extensions that would be added to stately homes to house and protect citrus fruits and other more delicate plants during colder months, like a more solid greenhouse. Therefore, the designs that we recognise as ‘orangeries’ are most often more traditional in design, offering a classical design to suit a country manor or stately home design.

The design of an orangery normally has a brick or stone base with a partial height wall on which the glass extension is added. The roof of the orangery is often flatter than a conservatory design with a central rooflight or roof lantern.

This conservatory in Devon was created in an orangery style using frameless glass, slim sliding doors and a flat solid roof.
This glass extension on the south coast was created in the style of an orangery using structual glazing with integrated aluminium casement doors.

How Do I Get a Glass Extension?

Due to the complexity and design variation of glass extensions, your best option is to speak to an architect to start with to get some ideas together as to what will be possible for your building.

IQ Glass provide advice and guidance on the possibilities of glass within such glass extension projects.

Just get in touch with the team today to chat about your project. Click here for all the ways to get in touch with us including social media, telephone or email.

Tags on this post