Steel framed box extension added on the back of a terraced chelsea property Case Study's

Gatsby House

Home renovations of a Grade II listed building in Chelsea with glass box extension, steel casement door and frameless rooflight.

Mondrian Glazing worked in conjunction with the architects Atelier West to install a vintage style extension onto a Grade II terraced home. The contemporary extension features a steel casement door and a frameless rooflight.

glass box extension on the end of the building, looking in from garden

The property Gatsby House was built in the mid-19th century, originating in the Victorian Era. During this time period, there was a huge influx of people migrating to urban areas, which resulted in a significant increase in terrace houses. The utilisation of small spaces meant building taller properties that cover less floor space.

The small amount of living space available in these properties has given rise to the popularity of extensions throughout the most densely populated areas of London.

When creating a terraced extension, it is critical to expand the area of living space without the loss of available light. Increasing the light is important as compared to other semi-detached and detached options, terraced houses have less access to natural light.  

Gatsby House is a perfect example of the expansion of space whilst increasing light availability. The box extension and rooflight allow for an abundance of natural light whilst the extension increases the functionality of the former garden space.


Glass Box Extension from the inside, black glazing bars and frameThe glass structure is a more contemporary design, but the RAL powder finish of the steel and the addition of the glazing bars were carefully considered. The addition of these features aided in the creation of a consistent vintage aesthetic flowing seamlessly throughout the property.

The elegant frames and contemporary glass box design contrasts beautifully with the traditional brickwork of the terraced home, creating a striking design feature.

Although the installed system has more of a vintage appearance, its performance is cutting edge. The steel system is thermally broken to prevent heat loss, increasing its sustainability by requiring less energy to heat the home, and to meet modern performance regulations.

The narrow house design is open plan, with the extension complementing this design by creating the illusion of a larger space with the addition of so much natural light. The casement door leads out into the paved garden and al fresco dining area, creating a more cohesive space from the indoor living area to the garden.


Glass Box extension with steel frame and glazing bars in black thermally broken

The roof extension included the installation of a frameless rooflight, allowing even more light into the property. The steel features of the rooflight were designed to replicate the traditional design of the home.

If you are interested in any of the steel products discussed, then please contact us at Mondrian Glazing.



Photo credit: Atelier West

Peter Landers Photography

Steel patio doors on single storey kitchen extension Case Study's

Triptych House

Contemporary Architecture

Triptych house is a Grade II listed dwelling in Winchester, Hampshire, located next to a large 18th Century manor house.  The extension and renovation of this property was carried out by Paul Cashin Architects who specialise in modern, thoughtful and sensitive building and design projects.  

Modern kitchen with steel patio doors and rooflight


The single-storey conservatory-style kitchen and dining space at the rear of the property has been installed with the Mondrian external double doors with sidelight and solar control glass.  The client wanted to upgrade the conservatory into a new contemporary extension as well as renovating the rest of the property. 

A representative of Paul Cashin Architects stated, “When dealing with existing buildings, we always look to enhance the inherent character of each space, rather than work against the architecture of the building. We see our work as enabling each building to embody its underlying qualities and for each room to become more ‘itself’.” 

This is shown with the use of the Mondrian Glazing system as the aesthetics allow for a contemporary design to blend in with a more traditional renovation project so was a great choice of door system for this grade II listed property.

 Steel patio doors on single storey kitchen extension


All Mondrian windows and doors are made to measure by the artisan fabricators at IQ Glass UK.  The steel systems are finished individually by hand, ensuring the strength and quality of each welded connection.  This specific external Mondrian glazing system measures at 3600mm wide and 2300mm high with a slim framing of only 57.5mm.  The frame is thermally broken for enhanced thermal insulation providing a Uw value of 1.5 W/m2K.


Modern kitchen with steel patio doors