08/07/2014 06:26 BST | Updated 07/09/2014 06:59 BST

Conserving The Past Must Not Curtail The Future

Picture the scene: a new bridge is built in London, and the public hate it. An architect comments that "it represents the vice of tawdriness and pretentiousness" and a local paper calls it London's "ugliest public work". What was this architectural monstrosity? None other than London landmark Tower Bridge.

So it was, so it is now, and so it has always been: many of the City's 17th century Aldermen were furious with Sir Christopher Wren's design for a dome-shaped St Paul's Cathedral instead of the traditional spire. Now it is rightly regarded as an architectural masterpiece of its age and Londoners and tourists alike pose for photos on its step. There has always been a tendency to cling to what we know, to fight what is new and to dislike what is different. The City has been home to iconic architecture from the Roman Temple of Mithras (the remains of which have been uncovered as the foundations are dug for the new Bloomberg building) to the iconic inside-out Lloyd's of London building.

However, not all of the City's architecture has been as deserving of such accolades, and in our haste to preserve the past at all costs, we risk severely curtailing the possibility of more great architecture in the future. From the closely packed wooden buildings that burned so fast in the Great Fire of 1666, to the shoddy post-war office blocks that filled the gaping holes left by the Blitz; the City has had many less than stellar buildings in its time.

Fortunately for anyone who has ever worked in a draughty 50s block with no lift or disabled access, many of these substandard buildings have been demolished, paving the way for new developments such as Paternoster Square, which combine welcoming public spaces with office blocks that meet the needs of modern businesses. One of the often overlooked changes that technology has brought about is the move from narrow office buildings with rows of offices either side of a long corridor, to open plan offices where employees cluster in groups. This meant that some of the old office stock was no longer functional or practical - especially as the arrival of computing technology rendered air conditioned offices and telecoms a business necessity. The Big Bang was another big moment of change, as firms grew larger and office requirements changed. Some of these changes produced iconic new buildings such as the Lloyd's of London building, which has added to London's architectural richness.

However, unlike in the post-war period, there are no longer any vacant sites to play host to new architectural treasures. If the City is to remain relevant to today's business environment, it needs new buildings equipped with modern technologies. For these to be built, some of the concrete buildings of the fifties and sixties will have to come down. It is a mark of the City's resilience that they were built so quickly in a Blitz decimated City, but they are no longer fit for purpose. In the same way that some of the City's grand 18th century buildings replaced cramped and dangerous building stock, so today have many of the concrete buildings of the sixties been pulled down and replaced with high quality, modern office blocks which are better equipped for today's working world - environmentally friendly, accessible by all and more pleasant to work in.

If the City is to retain its position as a pre-eminent business centre, it needs to be able to accommodate a growing workforce. Restricting the supply of current buildings that are available for demolition could act as a dangerous brake on the City's continuing success as a world leader. The City is not a place that can stand still: whether because it has to, because it needs to or because it wants to, it is always being renewed - one building, one development or one street at a time. Yes, old buildings can be beautiful - and so can new buildings, as the Gherkin's popularity proves, but we cannot preserve the City in aspic at the expense of its workers and residents.

So although standout buildings such as Lloyd's of London, the Gherkin or the Cheesegrater may deserve a place in the line-up of London's great icons in years to come, we must be careful not to fall over ourselves rushing to preserve the buildings of today if it means missing the opportunity to play host to the next St Paul's or Royal Exchange. We need to be pragmatic about the City's evolution if our world-renowned architectural landscape is to be joined by new treasures.

After all, many of our greatest buildings are testament to the new ideas that have always been part of the City. They serve as a social memory, transmitting across the generations the story of our society. That story shouldn't end in the past but should look resolutely to the future, and the needs of the next generation of businesses in the Square Mile.