An updated, postmodern value framework for architecture preservation is needed to protect buildings that are young or ubiquitous as well as those that are exceptional, writes Owen Hopkins.

It's not uncommon for architects and clients to disagree. In fact, it's often better that they don't entirely see eye-to-eye. A lively exchange of ideas and opinions often leads to a better building.

However, it is unusual for a client – or rather funder in this case – to disagree so much with one aspect of the design that they leave a letter hidden inside anticipating its future removal and their ultimate vindication. Yet, as was reported last week, this is exactly what happened when a column in the foyer of the Sainsbury Wing of the National Gallery in London was removed as part of Selldorf Architects' controversial remodelling of Venturi Scott Brown's famous scheme.

It is hard to imagine any other Grade I-listed building in Britain being treated this way

The letter, from the project's funder, John Sainsbury, who died in 2022, relayed how he thought the column was a "mistake" that "we would live to regret" and how his future self would be "absolutely delighted that your generation has decided to dispense with the unnecessary columns".

Anywhere else this would simply be an amusing incident and example of the age-old tussle between architect and client. But here it brings to the fore once again the argument around the Sainsbury Wing's transformation, of which the removal of these columns is a part, and, more broadly, about the preservation – or lack of it – of postmodern architecture.

Whatever one thinks of Venturi Scott Brown's work or the alterations now underway, it is hard to imagine any other Grade I-listed building in Britain being treated this way.

The very idea of postmodern heritage presents something of a paradox when it comes to preservation and listing, with buildings of that era frequently evading many of the categories by which decisions of "significance", and ultimately of value, are made. Partly as a result, postmodern buildings are increasingly being lost, with the furore over the Sainsbury Wing following contentious redevelopments of several seminal projects in the USA, such as Helmut Jahn's Thompson Center in Chicago and Philip Johnson's AT&T building in New York.

It pays to be suspicious of decision-making systems that claim any kind of objectivity, as the listing system inherently does. And the fate of these and countless lesser-known examples of postmodernism points to the deficiencies and broader ideological underpinnings that determine why some buildings are deemed worthy of preservation and others allowed to be heavily altered or even demolished.

One of the great ironies of the prevailing concept of heritage is the extent to which it is founded on a modernist value system. This, weirdly, is one part of the modernist philosophical edifice that still stands, arguably stronger than ever. But this close connection is really no surprise given the way their histories are intertwined, with many conservation movements arising in response to the modernist wrecking-ball being directed at historic cities in the 1950s and '60s.

We urgently need more open, inclusive and progressive understandings of heritage

To prove the point, just look at the language that the UK Government uses in its Principles of Selection for Listed Buildings, which talks of buildings' "importance", "significance" and "virtuosity", their "innovation", "distinction", "merit" and "rarity", and how they might "represent" or "illustrate".

While it's possible for a building to meet these criteria in any number of ways, running through them is the assumption that a building's value is predicated on the extent to which it has broken new ground and somehow driven architecture as a whole forward, as opposed reflecting existing trends. It's a way of assigning value that is still frequently taken for granted – and not just in architecture – yet is entirely ideological, reflecting a belief in the idea of architectural "progress" and development that, quite aside from questions of style or aesthetics, was at the core of the modernist world view.

This doesn't just affect postmodern architectural heritage, of course, but shapes how we designate and value heritage of all kinds. And, despite attempts by well-intentioned heritage officers to negate it, results in a system structured to exclude certain buildings and the people and histories connected to them.

Indeed, this is not a simply a question of the built environment, but of how our collective histories are written and by whom. In an ever more politically polarised and divided world, we urgently need more open, inclusive and progressive understandings of heritage. So, instead of the exclusive and restrictive modernist concept of heritage, how about a postmodern one that actively embraces the possibility of multiple value systems?

But what would this mean in practice? Well, rather than valuing buildings for their originality or uniqueness, we might privilege those that are commonplace or ubiquitous, buildings that aren't exceptional and instead part of everyday life like shopping centres, multiplex cinemas, leisure centres or housing estates.

Then there's the requirement that buildings stand the test of time, reflected in Historic England's rule that buildings have to be 30 years old to be eligible for listing. It's why we lost buildings like Terry Farrell's TV-am in North London (pictured) – a wonderfully bold and colourful building that epitomised the energy of the early 1980s, but for that reason soon went out of fashion and was remodelled before anyone thought of listing it. So, let's invert the 30-year rule and specify that buildings can't be demolished until 30 years after their completion.

Heritage is not about the past, it's about what we value enough to preserve for the future

One of the things that counts against a building when being considered for listing is alterations. Which brings us back to the Sainsbury Wing, a building that was always conceived by its architects explicitly as an addition to the National Gallery, and thereby in the modernist concept of heritage is of inherently lesser value.

But what if we looked at alterations not as things that harm a building's significance, and instead as positive evidence of its changing use, thereby enhancing its value? Sometimes the modification is actually more valuable than the original, which is certainly the case comparing Venturi Scott Brown's addition to William Wilkins' uninspired original building.

A criticism of the above approach is that it ultimately leads to the preservation of everything. This may not be a bad thing given the urgent need to change fundamentally our attitude to demolition. But more realistically a postmodern concept of heritage could inform an alternative, supplementary set of principles for listing.

For example, it would be relatively straightforward to create a carbon-based value system, so that buildings with particularly high embodied carbon are automatically preserved. Or it could be stipulated that those buildings with a vital social or public purpose should be preserved – at a stroke protecting every council house in the country.

Heritage is not about the past, it's about what we value enough to preserve for the future. Changing how we designate architectural heritage will also change what new architecture is produced. If we restrict the demolition of buildings with high embodied carbon, it will undoubtedly lead to few new ones getting built.

Yet, a more inclusive concept of heritage arguably has an even bigger role to play in helping ensure a diverse and pluralist built environment, and in turn helping pave the way for a more open politics and culture. A city that has room for every building has room for everyone.

Owen Hopkins is an architecture writer, historian and curator. He is director of the Farrell Centre at Newcastle University and was previously senior curator at Sir John Soane's Museum and architecture programme curator at the Royal Academy of Arts. He is the author of eight books, including Lost Futures: The Disappearing Architecture of Post-War Britain (2017) and Postmodern Architecture: Less is a Bore (2020).

The photo is by Richard Bryant.

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