Preservation vs Conservation Architecture – What’s the Difference?

The two concepts play separate, but equally important roles within architecture.


18 Apr 2024


Matthew Sharman

You stand in a flower-filled meadow.


It has taken you most of the morning to get here, a beauty spot that is cut off from roads, public transport, and, seemingly, the very concept of civilisation itself, but rising before you now is your next architectural project, a beautiful but very rustic farmhouse.


While its rough-hewn stone walls are as vertical as the day they were constructed, the windows, roof and chimney are all crumbling shadows of their former glories. It was once home to respectable hard work from a bygone era, but today the building accommodates nothing more than uncontrollable ivy and a diverse array of wildlife.


In short, what you are looking at, if you gaze beyond the wear and tear of time, is a restoration opportunity. That restoration could take many forms depending on the principles that you will be adhering to (often dictated by the historical significance and character of the structure, as well as local planning rules) and the result you want to achieve, but the two main methods are conservation and preservation.


At first encounter, you might think that the difference between conservation and preservation in architecture is purely one of semantics – surely they mean the same thing; in fact, it is important to set the two apart from one another because whichever one you choose will have a strong influence on the end result.

What is preservation architecture?


Preservation architecture is primarily concerned with the overall fabric of a building and its historical design, incorporating as much of the original material as possible when making repairs or adding any features. 


The result of your preservation efforts should be the retention of the building’s innate characteristics – a visitor present when the structure was originally built will still be able to recognise it once your project has been completed. If an individual church window shatters or its distinctive 14th-century tracery becomes damaged, for example, and you were adhering to preservation principles, you would try to fix it or replace it with a likeness as near to the original as possible using materials that are in-keeping with the other windows and character of the structure.


Returning to our diamond-in-the-rough farmhouse, its windows likely disappeared with its original occupants a long time ago. You might, therefore, take the opportunity to replace them with energy-efficient bespoke glazing that looks exactly the same as those in a faded photograph but utilises modern technology to improve the sustainability credentials of your project. In doing so, you have not changed the fabric of the building – because a window still appears in the same place – but you have improved it.


The key thing to note is that while you might have replaced the window with identically shaped glazing, you have not irredeemably altered the structure; the farmhouse still retains its original character and is recognisable to anyone who saw the original.


Premium glazing is a particularly useful component of preservation architecture because its transparency – when executed correctly – ensures the viewer can always recognise the original building. So even if you were to construct a glass box extension or Victorian side return, you would still be able to see the fundamentals of its pre-existing design.


What is conservation architecture?


Conservation architecture is entirely led by the building itself because any repairs or additions should not remove, alter or permanently bond to any original material. Furthermore, any work that you carry out must be reversible or removable, leaving the original material in exactly the same state (wherever possible) as when you found it.


Whereas architectural preservation is concerned with the overall appearance of a structure (insomuch as its innate character and intended design are preserved), the purpose of a conservation project is to freeze what is left and conserve it for future visitors. 


Let’s say that your farmhouse has a captivatingly deep well right in the middle of it. It’s somewhat crumbling because it has been left to the elements, but – with a little protection – could easily survive for a few more centuries, if not a few more millennia. The preservation method might involve adding new stonework to the well that appears just as the original might have done; but if you choose conservation as the best tactic, you could choose to simply cover the well with a glass case or glass floor if the well is entirely recessed into the ground. In doing so, you are not bonding anything to the well and it remains unchanged from when you found it.


As we will see in the next section, conservation architecture is particularly useful when displaying archaeology within a museum or visitor centre.


What is an example of preservation architecture?


St Paul’s Cathedral, London

Leaving our flower-filled meadow behind and stepping into Christopher Wren’s magnificent creation, we find an excellent example of preservation architecture right in the heart of our capital city. 


St Paul’s Cathedral was constructed in 1675 following the Great Fire of London and appears not to have aged a day. While this fact is, in part, due to the careful management of the 1.5 million annual visitors flocking to the site each year, it can also be credited to the custodians’ ongoing and meticulous maintenance. For example, the cathedral’s most impressive feature is, arguably, its main dome (which actually consists of three domes in one structure), but over time, the dome’s lead has begun to break and degrade. As a result, preservationists have removed the damaged materials and replaced them with new equivalents, ensuring that the roof remains weatherproof and structurally sound for generations to come.


Similar preservation efforts are being undertaken on the stained-glass windows, wooden furnishings, and even the foundations themselves. After all, London has changed a lot in 350 years, so the building needs to adapt to those changes.


What is an example of conservation architecture?


Roman Villa Museum at The Newt in Somerset

In 1882, labourers working on the Hadspen Estate (now the Newt Estate), began finding Roman artefacts whenever they put spade to soil. Over the next 140 years, successive archaeological excavations uncovered the remains of a grand villa from the early Roman period and, dated before that, an Iron Age settlement.


These were important finds that called for the construction of a state-of-the-art museum – one that put the visitor at the heart of the experience, without impacting the remains. As glazing specialists, we built a 48-metre frameless facade to contain and protect the archaeology with striking, unobstructed views over the surrounding landscape. Stepping inside, you will find a suspended glass walkway, ingeniously suspended from its own balustrade above the illuminated remains of the villa.


We think this project is a prime example of conservation architecture because if you took away all of the structures built around the Roman remains, it would be a big shame, but – more importantly – the archaeology would have been unaffected by the modern building work and subsequent dismantling. 


While this is quite a niche – but no less impressive (even if we do say so ourselves) – example of conservation architecture, another might be the Mary Rose Museum in Portsmouth, in which 19,000 objects – including the ship itself – sit behind modern glazing, fulfilling two purposes simultaneously: visibility and protection.

Which architectural method would be suitable for your project?


Let us return to our rustic farmhouse one last time.


If your goal is to revive it to its former glory, preserving its original charm and allowing any visitors to connect with the historical narrative embedded in its design, preservation architecture could be the preferred route. This approach involves meticulous attention to detail, and perhaps utilising premium materials like bespoke glazing to replicate the original features while embracing modern technology for sustainability. Preservation allows for a harmonious blend of the old and new, ensuring the farmhouse retains its distinctive character even as it undergoes essential repairs and enhancements.


On the other hand, if your vision for the farmhouse involves maintaining its existing state with minimal intervention, allowing the structure to stand frozen in time, conservation architecture might be the more suitable choice. This method prioritises the protection of the existing material above all else, ensuring that any repairs or additions are reversible and do not alter the farmhouse’s current state beyond what is necessary.

In conclusion, what is the difference between conservation and preservation in architecture?


As you might have already discovered, defining the difference between conservation and preservation is rather difficult, but doing so is both possible and important if you are embarking on a restoration project. Preservation architecture taps into the character of a structure and seeks to recapture the essence of the building at a particular moment (often when it was first built). You might add an extension here and a modern feature there, but the basic DNA of the structure will remain the same. 


Conservation, on the other hand, takes exactly what is in front of you today and protects it for the future. It is the most hands-off approach of the two, preferring no architectural work to take place over work that could damage the building. It is for this reason that conservation architecture is the route chosen by most museums and visitor centres that have a vested interest in protecting their exhibitions.


But what about your project? Are you still standing in that same wildflower meadow daydreaming about the potential of a dilapidated building that has long since lost its way? If so, we can help – speak to our team of experts today.