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The Ultimate Guide to Glass Roof Extensions

Glass roof extensions offer the advantage of extra room, lots of natural light, and views of the sky and garden.

Like with any home addition, you should carefully examine what the new room or rooms will be used for. For example, a glass roof meant for a kitchen extension will not be the same as one meant for a new living room or home office where glare may be a problem.

Take a look below for some fantastic ideas and solutions for glass-roofed additions. Planning permission, overheating and overlooking are concerns that should also be addressed before building.

Considering glass roof extensions

When considering a glass roof extension, it is important that the homeowner and architect work closely in-order to fully specify and design the perfect extension with the correct glazing.

When working with the minimal windows team, we would require some architectural drawings to develop a quotation for the glazing as part of the extension. These drawings will provide a greater understand of the scope and requirements of the project.

Things to consider for glass roof extensions:

  • What will the extension be used for?
  • Where will the extension be?
  • Should you specify sliding doors?
  • Thermal performance

Glass roof extension placement and function


The placement of an extension with a glass roof is crucial.

Throughout the summer, a south-facing addition with a glass roof will receive plenty of sunlight. Though that may sound ideal, the area may be susceptible to overheating in the hottest part of the summer depending on how much glazing you add. That is, unless you have taken precautions during the design and construction phases to avoid overheating (such as solar control coating the glazing) 

While facing north may not seem like the ideal placement for most, the diffused natural light is actually some of the most beautiful and consistent, which is why artist studios and museums like to use it most often.


The purpose and of your house addition will have a significant influence on the glass roof’s design.

Installing the glass roof in the part of the building that is exposed to a great deal of light will benefit areas with high traffic, such as a kitchen or family room/communal area. This means that the glass roof will illuminate the space throughout the day, saving on energy usage in a home or building. 

Glass roof extensions can also serve a purpose for a room used as a home office. A smaller glass extension can provide a smaller deal of natural light to an area to improve quality of living.

The thermal performance of the system is also important. With large amounts of glass it can be a concern that overheating will occur. Solar control coating and shading methods can be used to stop any overheating.

Glass roof extensions with slim sliding doors.

Main Street

The owners of this traditional-style house desired to develop an airy, well-lit open-concept kitchen and dining space. As a result, an oversized structural glass roof and biparting sliding doors were added to the glass box extension.

The modern extension was designed with a significant focus on biophilic design, as part of the brief that involved creating a place that emphasised a connection to nature.

The flooring material used inside the expansion and the garden’s outdoor seating area is the same, providing a sense of continuity and enabling the indoor and outdoor spaces to be fully integrated when the doors are open.

main street winter garden room
Glass room extensions

Chaldon Road

The double-height side infill expansion at Chaldon Road immediately stands out from the exterior and interior designs.

Above our well-liked minimally framed sliding glass doors, fixed frameless structural glass modules were placed to create a double height elevation of glass.

For a smooth externally glazed look, the base of the structural glass panel is stepped over the necessary steel supports of the doors below.

The structural glass panel’s head was designed to slope in the direction of the glass roof design, which resurfaces along the side of the narrow extension after emerging from the back elevation.

Chaldon rd glass roof extensions 2

Dalston House

This minimal glass addition was a component of a bigger renovation of an East London family house. The house needed a modern touch, but the architects also wanted to preserve the areas’ individuality and character.

The new additions on the back of the property consist of two sleek black boxes. The compact frame of the building and the nature of the glass extensions resulted in a narrow footprint for the structure.

To the rear elevation, the longest of these slender glass extensions contained a straightforward arrangement of unadorned windows. This two-pane sliding glass door gave the small area the direct garden access and minimum glass design that was needed.

If you would like more information regarding any glazing systems, click here to request our data sheets.

Dalston glass roof extensions 2
Dalston glass roof extensions 1