Bradbourne Street

A structural glass roof to a side infill extension in South West London

This property is a traditional terrace townhouse on Bradbourne Street in South West London. The main element of our glazing works on this project consisted of a side infill extension with a glass roof to the rear and side elevation of the property. The side infill extension will allow more daylight in, repurpose a disused area of the garden as the side of the property and improve the connection to the garden.


The homeowners had redesigned the layout of their home to create a layout that beautifully flowed into the garden and provided abundant open plan living spaces for the family. Part of this design was to move the kitchen to the rear of the property and create an indoor-outdoor living environment.

The architects ‘Mackay and Partners’ wanted to create as much light in the kitchen whilst keeping the space thermally insulated to a high level. To achieve this, they designed an 8-metre long roof section of the side infill extension to be filled with structural glazing. This large glazing installation allows the sunlight to penetrate directly through into the kitchen below, resulting in a well-lit living space.

IQ Glass UK designed and installed high thermal performance glass units in this structural glass assembly to the side infill extension in South West London. These structural glass units perform to a 0.6 u-value even when installed horizontally, a dramatic improvement on standard glazing which struggles to achieve a 1.7 U-value when installed as horizontal glass.

The glazing was installed as 5 panes joined together and supported by slim steel bars in between each pane. This kept framing and visual obstruction to a minimum to allow maximum levels of natural light into the kitchen.

The roof glazing was installed at a light angle to allow water to run off and reduce the loading on the surface. Installing roof glazing at an angle is especially important when low maintenance glass is used, as the angle of the glass helps to encourage rainfall to wash dirt and debris away.

Side infill extensions are an outstanding way of transforming narrow, dark rooms at the rear of a property into a contemporary and light living space. These extensions are built within that slim strip of outside space that runs alongside the rear part of many terraced and even semi-detached houses. In London, many traditional townhouses and terraces were built with this outdoor space which is often being repurposed to extended the indoor rooms.

Adding a single storey extension within these spaces transforms existing back rooms into a spacious area that’s ideal for a generous kitchen, dining room or living area. Although some garden space is sacrificed, a well-designed side infill extension can improve the connection to the remaining garden.