Product Innovation
Steel-look aluminium windows ease pressures on listed buildings refurbishments
Replacing original steel windows in listed buildings and conservation areas has long been a fraught exercise. Planning constraints, aesthetic scrutiny and the technical shortcomings of legacy systems often collide, leaving specifiers and homeowners with limited options. The challenge is familiar: how to preserve historic character while meeting modern expectations for energy efficiency, security and cost.
The Royale Stepped Window, developed by Duration, positions itself as a solution to that dilemma. Designed specifically as a steel replacement system, it aims to remove much of the complexity that has traditionally accompanied heritage fenestration projects.
Designed for Authenticity – At the centre of the system’s appeal is its visual accuracy. The Royale Stepped Window features a 32mm matching outer frame, delivering slim sightlines that closely replicate those of traditional steel windows. In listed properties and conservation areas, where even minor deviations can prompt objections from conservation officers, these proportions matter.
The emphasis on detail extends beyond the frame. Traditional hardware options—including period-style locking handles, peg and stay fittings and heritage hinges—allow replacements to sit comfortably alongside original architectural features. The result is a window that is, at first glance, difficult to distinguish from the steel frames it replaces.
Modern Performance, Discreetly Delivered – While appearance is critical, performance is where many historic systems fall short. Manufactured from high-performance aluminium, the Royale Stepped Window achieves an ‘A’ rated Window Energy Rating (WER), combining slim aesthetics with contemporary thermal standards.
Internally glazed 18mm double-glazed sealed units contribute both to energy efficiency and to improved security, supported by a high-security locking system as standard. Importantly for sensitive refurbishments, these gains are delivered without altering the external character of the building.
Cost and Practicality in Refurbishment – Cost has historically been another barrier to steel window replacement. Traditional steel systems are expensive to manufacture and install, particularly where on-site alterations are required. By contrast, the Royale Stepped Window is positioned as a cost-effective alternative, offering significant savings without sacrificing visual or technical performance.
Installation is designed to be straightforward. The slim frame allows units to be fitted directly into existing steel apertures, timber subframes or masonry openings, avoiding the need to cut back plaster, brickwork or surrounding finishes. For occupied buildings, this reduction in disruption can be as important as the financial savings.
Bespoke by Design – Each window is made to order, with a range of seven glass designs available, including square or diamond leaded patterns. Customers can specify butted or flat horizontal astragal bars, reinforcing the system’s flexibility across different architectural styles.
Finishes are equally adaptable, with more than 200 RAL colours available and options for single or dual-colour treatments. A 10-year warranty underpins the product, reflecting its use of premium materials, modern manufacturing processes and established supply chains.
A Benchmark for Heritage Fenestration – The Royale Stepped Window has been on the market for more than a decade, during which time it has established itself as a reference point for aluminium steel-replacement systems. Its combination of authentic appearance, thermal efficiency, cost control and installer-friendly design addresses many of the long-standing frustrations associated with heritage window replacement.
For listed buildings, conservation areas and even new-build projects seeking a timeless aesthetic, it offers a pragmatic balance between preservation and progress—removing much of the planning headache without rewriting the architectural story.
Tel: 01268 681612
E: sales@duration.co.uk
