To save historic buildings, we must let them change.

Historic buildings endure thanks to periodic intervention. Their relevance does not come from being treated like an untouched museum artefact, but from the layers of use, repair, alteration and adaptation that have enabled them to retain purpose and value over long periods of time.

The most interesting stories in a building’s history are often their moments of evolution. As such, the default judgement of viewing change as harmful to heritage significance should be reconsidered. More focus should instead be placed on the justification for change and the quality of its implementation.

Giving historic buildings a future means allowing them to adapt to new uses, serve new needs and extend their useful life for generations to come.

Historic buildings shouldn’t be frozen in time

In London, where much of our work at Prest Vale Architects is based, buildings dating from the medieval period through to the Victorian era and 20th century sit cheek by jowl in an ever-shifting city where demand for space is acutely felt. More than 10,000 listed buildings occupy The City of Westminster alone. It would be easy to treat these as symbols of heritage rather than as living parts of the urban fabric; occupied, shared, adapted, and capable of accommodating new life.

The pressures facing the built environment also demand interrogation into how we approach our stock of historic buildings. In July, a parliamentary committee called for a “reuse-firstapproach”, highlighting the potential for vacant and under-used historic buildings to contribute up to 670,000 new homes. The housing shortage, the imperative to reduce carbon emissions and a growing number of vacant or at-risk buildings (1,460 on the Historic England’s Heritage at Risk Register in 2025) all point to the same challenge: how do we keep existing structures in use and economically viable for the future?

Conservation must support change

Grosvenor’s 2026 Retrofit or Ruin report similarly argues that the long-term conservation of historic buildings depends on their ability to adapt, while highlighting a lack of confidence and consistency in heritage retrofit decision-making.

Too often, conservation decision-making treats change as the risk, rather than asking what happens when change is refused. A building left vacant and financially unviable is not necessarily being protected; it may simply be in slow decline, and its fabric cannot survive indefinitely through designation alone. For its value to endure, it also needs a viable use, an owner or investor willing to maintain it, and a realistic approach to the required interventions.

Historic buildings have rarely held a single, unchanging function. They have been extended, repaired and repurposed, with their survival often depending on their capacity to adapt.

Heritage requirements can protect important elements. However, if applied dogmatically and without sufficient consideration of the wider project, they can carry disproportionate weight against the broad range of considerations that make new uses viable. Viability is therefore a conservation issue. The answer is not to remove heritage controls, but to strengthen the understanding on which they are applied.

Understanding before intervention

A future-facing approach to working with historic buildings should be grounded in understanding. What is the building’s most appropriate future use, how will it give the building vitality and how can we design inflexibility? What should be retained? What absolutely needs to change?

These questions apply to listed buildings, but they are equally relevant to buildings without formal heritage protection. A listed building and a 1970s office block, for example, will have different materials, qualities and constraints. Both, however, can benefit from the same careful approach: starting with a forensic understanding of their existing fabric to inform the interventions needed to make their next use possible.

For nearly 150 years, the Society for the Protection of Ancient Buildings (SPAB) has argued for repair over replacement. As a SPAB Scholar, I have watched its principles of conservative repair, once the concern of a few specialists, find a far wider audience. It rests on close observation and a broad knowledge of different construction methods, together revealing how a building works and how it can go on working.

The same discipline pays off before a line is even drawn. Across projects at Prest Vale Architects, early detailed assessment and technical feasibility work establishes what is essential, what can be changed and how intervention can be justified. This lowers risk for investors and planning authorities alike, which matters increasingly as the embodied carbon and financial cost of construction becomes harder to ignore.

Our projects apply this approach across building types, uses, and scales, from a grade I-listed gatehouse repurposed with education and workspaces, to an unlisted warehouse transformed into a centre for health and wellness. In London’s Hyde Park, a grade II-listed former hotel had been derelict for two decades and placed on Historic England’s Heritage at Risk. The building was a genuine hazard to the city around it. After exploring a number of options for its most appropriate use, we restored and converted the original building into 11 high-quality apartments. The proposal included adding a six-storey extension to its northern elevation, which was essential to take pressure off the areas of highest heritage significance. This has enabled the new-build area to accommodate the more heavily serviced spaces, so the qualities of the historic rooms can be enjoyed as they were intended. The thermal performance uplift of a new-build north-facing facade has also enabled the integration of low-carbon energy supply throughout the building.

The tide has changed

Architects, clients, and authorities must become more willing to support thoughtful adaptation. If we make change too difficult, buildings stay vacant, and we risk losing qualities that made them significant in the first place.

The numbers show how much work remains. In 2025, 41 buildings and structures were rescued from the Heritage at Risk Register, but 63 were added; a net increase that underlines the need for greater momentum across the sector.

Adapting our built heritage is hardly a new concern, but it is moving from the margins of the profession towards its centre. Architects are well placed to sustain that shift and to make the case for adaptation more persuasive. Eric Parry Architects, Caruso St John, and Witherford Watson Mann each show different ways of responding to existing buildings and together demonstrate how wide the range of approaches can be.

The question is no longer whether we should adapt historic buildings, but whether we can afford not to. If we want them to last another century, we must give them a reason to be used