Jon Shooter, Managing Director at Glazing Vision, discusses how architects are using bespoke rooflights to meet key design and specification challenges.

Rooflights help increase energy efficiency and reduce reliance on artificial light by bringing natural light into the extension of this family home

Some 70 per cent of RIBA House of the Year 2023 shortlisted projects featured rooflights. It’s no surprise given how they enable architects to unlock design potential, play with daylight, increase ventilation and access unused space. Here, Jon Shooter, Managing Director at Glazing Vision, looks at recent projects to see how architects have used rooflights to meet specification challenges.

Flooding space with light
Many Victorian properties are gloomy, so homeowners rely on artificial light, impacting wellbeing, energy efficiency and sustainability. So, when Oasys Property Solutions designed a north-east facing extension incorporating a generous-sized kitchen/dining/living space, an abundance of daylight was a must.

We provided Simon Heckford, Director at Oasys Property Solutions, with technical advice and specified two flat Flushgaze rooflights, and a wall abutted bespoke rooflight. Simon commented: “There’s no questioning the quality and consistency of natural light from the rooflights. Even in the bleakest weather, they contribute to the light and airy feel of the extension.”

Preventing overheating
The climate crisis means regulating temperatures is increasingly important. Rooflights can play an integral role in preventing overheating and circulating fresh air. They can be operated by the homeowner, or state-of-the-art automatic opening rooflights can be integrated into building management systems. The former solution was chosen by Chris Dyson Architects to moderate temperatures in a traditional orangery and extension at a north London residence.

Insulated walls and energy-efficient double-glazing keep the orangery warm in winter. In summer, ventilation and comfort is controlled by opening the doors and a full-width Dual Sliding Over Fixed Rooflight equipped with sliding elements.

Manufactured in a bespoke bronze finish, this exceptionally large flat rooflight was precision-engineered in eight sections. The two end sections were manufactured to slide over the six fixed central sections, traversing in a side-to-side, rather than an up-and-down slope operation. The sliding sections are electronically controlled to provide a quiet and efficient operation, with a manual override for safety.

Adding a bespoke rooflight helps prevent overheating and circulate air in the traditional orangery of this family home

Bringing the outside in
City living provides many benefits, but it can mean there’s little or no outside space. To increase ventilation and bring the outside in, a stunning penthouse in Knightsbridge has incorporated a novel solution: open air dining within the confines of the building. Crucially, the clients wanted the option to close this off, making the room beneath weathertight, while maintaining high-levels of daylight.

The layout of the flat roof needed a substantial length of fixed glazing to be installed close to the proposed location of the rooflight, so options were limited. To overcome this, we designed a bespoke Sliding Over Roof Rooflight. This allowed a 100 per cent clear opening by retracting two glass sections independently in a sliding stacking arrangement. This maintains a minimal footprint as the glass only takes up half the adjacent roof space when fully retracted.

A bespoke Sliding Rooflight allows the dining room of this Knightsbridge penthouse suite to completely open up to the outside

Combining style with function
Since the pandemic, homeowners have been keen to convert flat roofs into usable spaces, as was the case in a Victorian terrace extension undertaken by Mulroy Architects. The challenge for Mulroy was to incorporate a rooflight above the kitchen, and utilise the roof space as a terrace. The rooflight needed to withstand foot traffic for unrestricted access. A flush finish was also needed, and the small pitch meant there was a potential drainage issue.

These challenges were overcome thanks to a large Fixed Walk-On Rooflight. As well as providing daylight and attractive sky views, its frameless design maximised usable space on the balcony. The rooflight was engineered with a 25.5mm clear laminate outer pane, 14mm Argon-filled warm edge spacer cavity, and 6mm heat soak tested toughened inner pane. It was tested to Class 0 and designed to withstand the uniform loadings of 1.5kN/m² and concentrated loadings of 2.0kN in accordance with BS EN 1991-1-1-1:2002 from the projected foot traffic.

Andrew Mulroy of Mulroy Architects said: “The client was very pleased with the rooflight and it delivered everything that was set out in the brief.”

Glazing Vision’s Flushglaze walk on rooflight not only floods the kitchen with light but means the roof can be used as a terrace (photo: Mulroy Architects)

Creating elegant access
Of course, not every outdoor space can be accessed from an adjacent room. When designing six modern townhouses in Islington, Tasou Associates incorporated roof terraces accessed by floating staircases. A major consideration was the headroom needed to meet Building Regulation approved document K requirements.

To achieve this, the architect specified three-wall glass box rooflights rather than manual hatch products. The access rooflights are fixed within the walls of the building, with one section sliding over a fixed one, which creates an approximate 50 per cent clear opening so there is no need for additional balustrades.

A three wall boxed rooflight provides elegant access for a roof terrace in a modern townhouse

As we’ve seen, rooflights and roof windows can transform a space by creating atmosphere with pools of light, opening a room up to the sky, or providing access to unused areas. To learn more about specifying rooflights that bring aesthetic appeal and functionality to your next project, download our suite of technical whitepapers covering the requirements of Approved Documents L, F, O, K & Q or request a CPD.

Contact Details
For more information, please call 01379 658 300, email, or visit the Glazing Vision website.