Oddicombe Cottage

Slim framed minimalistic glass box extension

This detached family home was suffering from a poor connection to the garden, at the back of the property, and a lack of natural light within the internal living spaces. The homeowners felt that especially for the ground floor rooms, more natural light would breathe more life into the property and improve the quality of the interior design. Therefore, the homeowners sought the expertise of the architects to design a rear extension that achieved these goals.


The architects proposed a single-storey rear extension to the detached home as it was a cost-effective option and would easily be accepted by the local planning permissions board. These simple yet effective single-storey extensions rarely require planning permission (depending on certain dimensions, materials, and location of the extension).

To this property, the architects wanted to construct a slim framed minimalistic glass box extension to allow an abundance of light into the ground floor rooms as well as the extension itself. There are many options for glass box extensions, they can be almost completely frameless, have integrated opening systems or be designed using slim aluminium framing. For this contemporary extension, the architects used a collaboration of structural glass, Sieger® aluminium casement windows and minimal windows® slim sliding doors.

This highly glazed extension utilised the minimal look for fixed structural units and minimal windows® slim sliding doors to create a frameless glass box effect. The structural glass units are completely frameless and offer a beautiful contemporary aesthetic to glazed extensions like this one. Minimal windows® sliding doors are a beautiful accompaniment to structural glazing as they maintain the exceptionally slim aesthetic achieved by the structural glass.

Minimal windows® slim sliding doors boast an impressive 21mm sightline that enhances the minimalistic aesthetic desired for this highly glazed extension. The structural glass fills the three walls of the extension with the sliding doors seamlessly integrated within the rear elevation. These slim framed sliding doors consist of one fixed pane and one sliding pane and allow a smooth transition between the indoor and outdoor living spaces.

Square edge Sieger® aluminium casement windows were used on the far side of the extension for ventilation. These aluminium windows are exceptionally slim in keeping with the minimal aesthetic offered by the structural glazing and the slim sliding patio doors. These casement windows are ideal to allow ventilation into the extension without having to slide open the sliding patio doors.

In the centre of the contemporary glass box extension, the architects designed a large rooflight to fill a large section in the ceiling, allowing natural light to penetrate straight down into the glass box extension. The rooflight is constructed from structural glass and supported along its span by minimal T sections allowing the maximum amount of natural light down into this windowless space. From above, the glass has a frameless appearance with all-steel supports internally.

Overall, the glass box extension creates a sophisticated connection between the indoor and outdoor living spaces and offers the homeowners a new space to relax. The glass allows a certain amount of solar radiation into the extension, but the use of solar control glass helps prevent the living space from overheating due to excessive exposure to the sunlight.