Human expertise combines with advanced manufacturing techniques to create The Rooflight Co.’s products, as featured in numerous buildings
A clear view up to the sky and a space flooded with daylight – even in the most constrained locations. These factors have turned rooflights into one of the most aspirational features of new builds and refurbishments. It’s why they can be seen in a string of award-winning projects, from Henning Stummel’s Tin House in London’s Shepherd’s Bush to Ann Nisbet’s Cuddymoss in rural North Ayrshire.
‘You can realise design possibilities with toplighting that you can’t get with windows,’ explains Peter Daniel, innovation director at The Rooflight Co.
Tin House and Cuddymoss are just two of many projects undertaken by The Rooflight Co. Whether heritage or contemporary, bespoke or standard, pitched, flat or walk-on, all their rooflights are made at its base in the Cotswolds. Design and manufacturing teams combine their human expertise, oversight and hand finishing with advanced manufacturing technologies.
‘Our approach is all about attention to detail, about doing things the right way,’ says head of architectural insights Keeret Eden. ‘We’ve brought a lot of processes in house so that we can control quality.’
The company, officially registered as The Metal Window Company but trading as The Rooflight Co, is best known for its authentic steel recreations of Victorian cast-iron rooflights. It was the need for such a product for his own designs that saw architect Peter King, working with wife Val, create the Conservation Rooflight and the firm that made it. That product remains a mainstay of the business, sold in its thousands each year.
The company’s broad expertise in the heritage sector has led it to work on such individual projects as the Victorian Derby Roundhouse, for which it made 48 bespoke trapezoidal rooflights, and, more recently, Rochdale Town Hall, Blenheim Palace and St Anne’s College, Oxford.
The Conservation range has been joined by the Conservation Plateau, a flat-roof product for heritage applications, the Neo contemporary flush-fit rooflight and the aluminium-framed Neo Advance, the contemporary flat-roof counterpart and its walk-on Skywalk+. The company has, meanwhile, gone through its own evolution. In 2019 Peter and Val King stepped away from the business, placing it in the ownership of its 40 employees.
The company’s foundational values have shaped its approach to working with designers. ‘Architects have very different needs,’ says Eden. ‘Some are interested in Passivhaus, some in heritage applications and some in premium contemporary solutions.’ But, she adds, for almost everyone, sustainability is key.
The company’s sustainability is confirmed by its Planet Mark and BCorp statuses. Having design and manufacture on site helps the firm’s committed employee-owners to bring a focus to all aspects of product and performance. Low-e glazing and argon gas cavity fill result in whole-window U-values between 1.0 to 1.4W/m2K, but the company’s ability to tailor its products allows it to produce triple or even vacuum-glazed rooflights. ‘Whatever the architects’ vision, we’ll work with them to realise it,’ says Daniel.
Because the silicone is hand finished, each rooflight has a unique hand-crafted touch
1 Hands-on design
For bespoke rooflight solutions, the company’s designers review a project’s parameters and create an early design. Working in Onshape and SolidWorks, they consider factors ranging from aesthetics and planning constraints to performance requirements, installation and access. The design team can tweak or combine classic designs to create individual solutions or turn to the firm’s library of past designs for prevalent features like pyramids. ‘For more complex projects, we design from scratch, modelling in detail and using that information for manufacture, working closely with our fabricators,’ explains design manager Kathryn Müller.
2 The coating process
Frames arriving from the Stoke-on-Trent based fabricator are inspected before being shotblasted and cleaned to give a good, dust-free surface. A 70-micron primer coat layer is spray-applied and the frame oven heated at 185 degrees for eight minutes to melt and bond the powder coating. Once the frame cools, its topcoat is applied in the same way. Paint thickness is measured at every stage. ‘Our minimum is 140 microns on a finished frame, but I typically achieve between 180-190 microns,’ says expert manufacturing technician Dicki Sollis. Blacks and greys are the most popular coating colours but the company has met orders for reds, yellows and blues.
3 Glazing
Insulated glazing units are entirely made in-house to assure their BSI Kitemark status. First, the glass is washed, dried and checked to ensure it is blemish-free. Then the aluminium spacer bar separating the glass panes is half-filled with desiccant and fitted to the primary seals and inner and outer glazing. This creates the cavity, which is 90 per cent filled with argon gas. The company uses two types of edge seal: structural silicone for contemporary applications and hot-melt for heritage. The workshop’s output extends to 3m-long and walk-on units with a standard insulated glazing unit being made in just eight minutes.
4 CNC cutting
The aluminium-framed Neo Advance rooflights are manufactured in-house from patented extrusions. Fixing-holes, vents and other essential openings in the frames are drilled using advanced CNC technology, which works to an accuracy of 0.1mm. Under the design-for-manufacture approach, each element of the rooflight is equipped with a unique job number, which unlocks all relevant information. The machine can then be programmed with the precise number, type and dimensions of openings it must cut, and how it must position the jig blocks needed to cut different profile types. The process is managed by a single operator.
5 Final assembly
Rooflight elements are now ready to be assembled into integrated units. As glazing units can be quite large, vacuum lifting gear is routinely used for safe handling. For contemporary aluminium designs, the thermal barrier is bonded to the frame before the insulated glazing unit is lowered into position and structurally bonded into place. A final application of a structural weather seal neatly completes the rooflight ready for final quality-control checks. A similar process is employed for steel rooflights.
6 Finishing details
Visual authenticity is critical for heritage rooflights, as is thermal performance. The Victorian-style glazing bars of the Conservation products are therefore purely aesthetic, presenting no risk of heat loss. Bars are added for an authentic look inside and out. As a final detail, the silicone sealant is hand-trimmed to recreate the effect of traditional putty. ‘Because the silicone is hand-finished, each rooflight has a unique hand-crafted touch,’ says innovation director Peter Daniel. ‘The closing stage is to ensure each rooflight has passed through the independently verified quality control system to ISO 9001, resulting in consistent premium rooflights handcrafted to precision.’