See the AT webinar, in collaboration with Selectaglaze and Velux, exploring how architects, customers, and conservation professionals are enhancing the performance of historic buildings while safeguarding their heritage value.
Historical buildings were not created for modern standards of thermal convenience, operational effectiveness or regulative compliance. Yet they represent a considerable percentage of the UK’s developed environment, and an irreplaceable cultural and material resource. For owners, architects and experts, the obstacle is hardly ever whether to step in, however how. So what practices and technologies can be implemented to enhance building efficiency without damaging or deteriorating the heritage possession? How do we reconcile preservation concepts with energy targets? And what are the best ways of handling risk, compliance and long-term stewardship in complex, protected contexts?
These questions and more were checked out in this AT webinar, supported by Selectaglaze and Velux. Chaired by Architecture Today Editor Isabel Allen, the event included presentations by Aimée Felton, Director of Estates and Preservation at The Charterhouse; Colin Bignell, Technical Sales Director at Selectaglaze; Rebecca Campbell, Partner at Studio PDP; Richard Williams, Senior Architectural Development Supervisor at Velux; and Matthew Wittrick, Associate at Purcell.
Once essential to the monastic life of the Charterhouse, Washhouse Court, now sits at the centre of a significant capital task to grow the resident community, improve the historical material, and enhance the internal living environment with a strong focus on sustainability (picture: The Charterhouse).
Aimée Felton opened the session with a client-side perspective rooted in the truths of handling a complex, living heritage estate. Speaking from The Charterhouse in London, a 3.6 hectare, primarily Grade I-listed website in continuous profession for more than 700 years, she challenged standard sustainability metrics. “We’re not driven by BREEAM or EPCs,” she discussed. “What we care about fundamentally is the human experience.”
Big chimneys added to the Charterhouse’s western range in 1613– 14 supplied heat to the pensioners’ spaces. Their brick stacks interrupt earlier decorative work, revealing the building’s progressive adjustment to changing living requirements rather than a single, set design solution (picture: The Charterhouse).
For Felton, the secret is comprehending how value is specified in a heritage context, where return on investment is determined not in financial terms but in operational effectiveness and social value. She stressed the value of questioning why interventions are proposed, and whether they really improve the lived experience of occupants or address real threats, such as obsolescence or system failure. “Historical buildings aren’t static things, they’re developing systems,” she kept in mind, promoting for incremental, educated adjustment rather than wholesale replacement.
Considerate secondary glazing from Selectaglaze was installed in The OWO Residences by Raffles in London, enhancing comfort and security(image: James Attree). Colin Bignell followed with a summary of how secondary glazing can deliver meaningful performance enhancements without compromising heritage value. “It has to do with operating at the crossway of preservation, convenience and efficiency,” he stated, explaining a completely independent system that upgrades existing windows from the within, preventing the requirement for replacement.
Selectaglaze slimline secondary glazing improves thermal performance while maintaining the historic material (picture: James Attree).
Bignell highlighted the ecological advantages of this approach, keeping in mind that keeping initial windows protects embodied carbon while extending the life of the structure. Thermally, secondary glazing can minimize heat loss by as much as 75 percent, while also enhancing acoustic convenience and security. Most importantly, these gains are attained through bespoke, minimally invasive setups that appreciate the character and detailing of historic façades. “It allows buildings to remain in usage for longer,” he included, “supporting adaptive reuse rather than demolition.”
Claridge House by Studio PDP is the net absolutely no retrofit and conversion of office back to domestic use over 2 floors of a 1920’s neo-Georgian structure in London’s Mayfair. The structure material was upgraded to fulfill LETI retrofit standards and customer Grosvenor’s strong ecological goals (image: Adam Parker).
Rebecca Campbell checked out how architects can fix up conservation with the increasing need for high-performing buildings. “The difficulty is boosting performance without jeopardizing the qualities that make these buildings valuable,” she stated, emphasising the need to understand a building’s heritage significance at the outset.
Dome to the main stair at Grade I-listed Cambridge Home, London, prior to Studio PDPs ambitious restoration plan that will change the structure and surrounding structures into a brand-new hotel (photo: Adam Parker).
At Studio PDP, this process is underpinned by a fabric-first approach informed by Passivhaus principles, alongside careful consideration of moisture movement in traditionally ‘breathable’ buildings. Through case research studies, including Claridge House in London’s Mayfair, Campbell showed how targeted interventions, such as vacuum glazing, vapour-open insulation and MVHR systems, can provide considerable energy improvements– in one instance accomplishing an 80 percent reduction in energy usage intensity. “It has to do with making sensitive, well-judged changes that secure a sustainable and meaningful future,” she said.
VELUX Heritage preservation roofing system windows were defined as part of a scheme to transform a run-down Victorian school shed into three cost effective artist studios in Newlyn (picture: Pip Hambling).
Richard Williams addressed the function of product innovation in heritage retrofit, concentrating on the concept of authenticity. “It’s about being considerate of the past, yet conscious of the future,” he discussed, describing the development of Velux’s preservation rooflight range in cooperation with architects and conservation officers.
VELUX Heritage conservation roofing windows are developed to blend perfectly with older structures (photo: Tony Ellis).
Williams highlighted the scale of the retrofit obstacle, keeping in mind that 38 percent of UK homes were constructed before the 2nd World War. Against this background, he argued that “the greenest structure is the one that already exists,” making sensitive retrofit essential. From flush-fitting rooflights that duplicate conventional profiles to cautious factor to consider of ‘curb appeal’ and roofscape consistency, his presentation underscored the value of visual coherence together with technical performance.
Purcell led the comprehensive repair of the grade I-listed Elizabeth Tower in London. The objective is that future repairs will not require to be undertaken for 50 years, protecting the tower for the benefit of future generations (image: Andy Bailey).
Matthew Wittrick concluded the webinar with insights from Purcell’s work on the Elizabeth Tower at the Palace of Westminster. Framing the job around 4 essential pillars: conservation, repair work, remediation and brand-new construct, he explained how the group balanced preservation with necessary upgrades to guarantee the building’s long-lasting future.
The job involved repair work to the original mechanical clock mechanism; a brand-new flooring and waterproofing layer at Belfry level; internal redecoration, consisting of plaster repairs and the application of breathable paint within the stairwell and rooms; installation of brand-new building services, including LED lighting and conservation heating; and the insertion of a brand-new set of lifts to provide better gain access to and emergency egress within the building (picture: Andy Bailey).
From stripping back layers of paint to enable the structure to ‘breathe’, to introducing brand-new lifts and services to enhance availability and performance, the task shows how contemporary interventions can be carefully integrated into historical fabric. Digital tools, such as BIM, likewise played an important function, enabling the creation of an in-depth digital replica to inform both current works and future maintenance. “These projects are about long-lasting stewardship,” Wittrick noted, “ensuring that heritage assets continue to perform and develop.”
Across the webinar, a consistent message emerged: improving the performance of historical buildings is not about imposing modern standards, but about working with the fundamental qualities of the existing material. Whether through incremental upgrades, carefully specified systems or delicate new interventions, the speakers concurred that successful heritage retrofit depends upon understanding cultural, ecological and social worth, and then creating accordingly.