Design Context and Challenges
The existing property had limited natural light at the rear, and the extension required glazing that would deliver both generous daylighting and clean contemporary detailing. The design required minimal sightlines and a seamless junction between vertical and overhead glazing, including glass-to-glass connections between the structural glazing and roof elements.
Slim framed sliding glass doors in RAL 8019, a grey-brown, provide direct access to the garden space whilst allowing the homeowners to view the garden from the dining area when the doors are closed. The sliding door is split into two, with one sliding and one fixed pane.
As well as traveling between the two environments, the sliding door adds ventilation to the space, which is particularly important in kitchen environments where humidity is higher.Above the dining room table, a large frameless rooflight from the Sieger range has been strategically placed to enable the natural light to stretch even further into the home. This fixed element, along with the other glass systems used, means the homeowners can use less artificial lighting in the daytime, helping them be more in tune with humans' natural circadian rhythm as well as saving on energy bills.
Several specific design challenges shaped the glazing specification:
- The extension combined different glazing types - sliding doors, fixed structural glass, shaped panes and rooflights - each requiring precise interface detailing.
- The rooflight siting and structural connections needed to maintain a frameless appearance both internally and externally.
- Drainage and water management needed to be integrated discreetly without impacting aesthetics.
- The extension design required glazing to different heights, including a 500mm‑deep structural glass transom above the main aperture.
IQ’s Glazing Solutions
The structural glass roof is split into large panes, joined with structural silicone for the most minimal finish. Using our Invisio structural glazing system, the system is fully thermally broken to ensure the internal environment is a comfortable living temperature all year round. Opting for thermally broken systems not only makes the space functional but can also save on heating and energy bills.
IQ provided a coordinated specialist glazing package, including:
- A 3036mm × 2616mm minimal windows® sliding door system, comprising two large sliding panes with a 21mm profile for minimal visual interruption.
- A 1392mm × 2968mm frameless structural glass panel, including a shaped/stepped configuration and glass-to-glass connection to the roof glazing.
- A three‑pane silicone‑jointed structural glazing section at 9351mm × 500mm, positioned above as a clerestory band.
- Integration of an IQ slot drain to manage drainage discreetly.
This combination created a clean, minimal elevation with uninterrupted views to the garden.
Rooflight Integration
Two rooflight configurations were supplied:
- A single‑pane 2867mm × 1368mm frameless rooflight
- A larger three‑pane 9351mm × 1392mm rooflight, silicone‑jointed for a continuous glass plane
The roof glazing was engineered to achieve seamless transitions between vertical and overhead elements, ensuring daylight reached deep into the floor plan. An optional
automated opening rooflight alternative was also explored for ventilation.
The structure of the extension was dictated by pillars, manufactured using traditional bricks and plastered in white on the internal face. The structural glass roof stretches beyond the pillar on one side of the extension, leaving a gap that has been filled with structural glass. Utilising structural glass in place of a brick wall allows more natural light into the property, forging a strong connection to the outside environment for an indoor-outdoor style of living.
