The successful retrofit of a listed building should not just be about preserving the past, but about preserving a building's ability to have a future. Most heritage buildings have layers that reveal past uses and alterations which in themselves, can become important pieces of history. To secure the future of our heritage assets, we need to identify and protect features with long-term value while allowing the building to start a new chapter. This is the philosophy we adopted for the retrofit of the Grade II listed Adelaide House in the City of London. 

Completed in 1924, Adelaide House was the City of London’s first steel-framed office building and the tallest office block at the time. A landmark of innovation, it featured electricity and telephone connections on every floor, central ventilation, and rooftop amenities including a rose garden and putting green. More than a century later, many of those pioneering features have either been lost or no longer meet current expectations.  

Buildings like this undoubtedly hold significant historic and architectural value, but if they fail to meet contemporary needs, they risk sitting empty and ultimately falling into disrepair. The aim is not to use change as an excuse to erase the past, but to ensure they remain relevant, valued and occupied in the future. 

Many historic buildings are already maximised in terms of height and volume, so the value often lies in extending their useful life with the minimum level of intervention required. The question is whether you attempt to meticulously recreate the original condition of the building, or embrace what remains and allow it to evolve. 

At Adelaide House, we identified elements that held genuine heritage value and ensured these were retained, protected and enhanced with new interventions, designed using a familiar material palette, expressed in a contemporary way. Rather than removing existing layers, we added new ones that can be adapted or reversed as future needs or styles evolve. By retaining elements of previous eras, the building preserves options for the future while maintaining a visible record of its history. 

This approach extends beyond conservation and into circular design. The original parquet flooring from the office areas was carefully removed, refurbished and re-used within the business lounge, giving existing materials a new purpose while preserving a tangible connection to the building's past. 

Historic fabric may survive for centuries, while services, finishes and workplace requirements will inevitably change many times over. We therefore viewed the building as a series of layers with different lifespans, allowing shorter-life elements to evolve without compromising those more likely to endure. 

Exposed MEP systems, for example, can be upgraded or replaced without major intervention, improving longevity and reducing disruption for future occupiers. The same thinking informed decorative elements and fittings, ensuring components most likely to wear or become damaged can be replaced without affecting the primary structure. 

The project was ultimately about finding the right balance between protection and adaptation, focusing on interventions that would deliver long-term value. Examples of this include introducing additional insulation internally, which although this reduced lettable area, the client recognised the long-term benefits in improving occupant comfort and operational efficiency. 

Other key interventions include enhanced accessibility and high-quality workplace amenities, bringing the building in line with modern occupier expectations, while the installation of new double glazed, openable Crittall-style windows and an all-electric strategy is set to support an EPC A rating and BREEAM Excellent certification. 

The success of Adelaide House shows that heritage buildings do not need to be frozen in time to be protected. On completion of the retrofit, three floors have already been let, demonstrating that the building continues to fulfil its original purpose. By carefully balancing conservation with adaptation, the project has secured the building's commercial viability and ensured it will remain an active part of the city for generations to come.