When I was still working for a big architecture firm a good friend of mine bought a Grade I listed house, and because I couldn’t be the architect, as I was too busy on other projects, I wanted to help them find a good architect.

It was one of those wonderful, slightly terrifying buildings that makes your heart beat a bit faster: beautiful, historic, full of character, and absolutely not the sort of place where you want to get things wrong.

As they started looking for an architect, they met lots of them. And, interestingly, almost every architect they spoke to said they had “good experience with listed buildings”.

And I remember thinking: that can’t possibly be true.

Not because those architects were being deliberately misleading, but because “experience with listed buildings” can mean many different things. It might mean someone once worked on a house in a conservation area. It might mean they submitted a listed building consent application years ago. It might mean they like old buildings. But that is not the same as really understanding them and understanding how the process of working with them is different.

And when you own an existing building — especially a listed one, but actually any older building — that understanding matters enormously.

EXISTING BUILDINGS ARE NOT BLANK CANVASES

With a new building, you are often starting with a relatively clear site. Of course there are still constraints: planning, budget, orientation, neighbours, ground conditions, and so on. But there is also a kind of freedom. A new-build project can be a wonderful opportunity for architectural expression because you are creating something from scratch.

Existing buildings are different.

You are never starting with nothing. You are starting with something that already has a history, a structure, a way of behaving, and often a whole series of alterations that have been made over decades or centuries. Some of those changes may be beautiful. Some may be harmful. Some may be completely hidden until you start looking properly.

That is the key difference.

Successful work on existing buildings starts with understanding what you already have.

Not with imposing an idea on it. Not with deciding too early what the “solution” should be. But by looking carefully, listening to the building, and working out how it functions.

OLDER BUILDINGS OFTEN WORK DIFFERENTLY FROM MODERN BUILDINGS

Something that is still surprisingly misunderstood is that any existing buildings, particularly traditional and historic buildings, were built using very different construction methods from modern buildings. They may have solid walls rather than cavity walls. They are probably constructed using lime mortar rather than cement which relies on moisture moving through the fabric of the building rather than being sealed out completely.

In simple terms, older buildings need to breathe.

That doesn’t mean they should be draughty, cold, or inefficient. But it does mean they need to be treated in a way that respects how they were built.

A lot of the major problems people have experienced over the last 20 or 30 years with retrofitting older buildings have come from not understanding this -. Insulation has been added in the wrong place. Impermeable materials have been used where breathable ones were needed. Ventilation has been reduced without thinking about humidity and how moisture moves. Solid walls have been treated as if they behave like modern cavity walls.

The result can be condensation, damp, mould, decay, woodworm, dry-rot and sometimes damage to the very fabric people were trying to improve.

This is where an architect who understands existing buildings can make a real difference. They are not just thinking about how something will look when it is finished. They are thinking about how the building will perform over time.

CONSERVATION EXPERIENCE IS NOT JUST ABOUT LIKING OLD BUILDINGS

There is a big difference between appreciating historic buildings and knowing how to work with them.

An architect with genuine conservation experience understands that existing buildings need careful judgment. They will be thinking about significance: what is important about the building, what should be protected, what can be changed, and where there may be opportunities for sensitive intervention.

They will understand that the value of a building is not always in the most obvious places. It might be in the plan form, the roof structure, a staircase, a particular material, a historic finish, or even in the way the building has evolved over time.

They will also understand that conservation is not about freezing a building in time.

Good conservation is not about saying “no” to change. Buildings have always changed. The question is how to make change intelligently, so that the building remains useful, loved, and looked after, without losing what makes it special.

THE STATUTORY FRAMEWORK MATTERS TOO

Of course, with listed buildings there is also the statutory side.

You may need listed building consent. You may need planning permission. You may be dealing with conservation officers, building control, heritage statements, method statements, specialist consultants, and sometimes quite detailed negotiations about what is acceptable.

Even outside listed buildings, there may be planning constraints, conservation area considerations, party wall matters, building regulations, and technical requirements around structure, fire safety, energy performance, ventilation, accessibility, ecology and moisture control.

An architect who regularly works with existing buildings should understand how these things fit together, preventing excessive delays because a bat survey was delayed or the listed building consent conditions not fully understood.

That does not mean they can magically make every permission happen. No one can promise that. But they should know how to shape a proposal and crucially justify it, so that it has the best chance of success. They should know what information is needed, when to bring in specialist advice, and how to explain the thinking behind a design clearly and convincingly.

That process is very different from simply drawing up what a client asks for and hoping it gets approved.

SO HOW DO YOU FIND SOMEONE WHO REALLY HAS EXPERIENCE?

This is the difficult bit. Because almost everyone will say they have experience.

So I think you have to ask better questions:

Instead of asking, “Have you worked on listed buildings?” ask:

“What kind of listed buildings have you worked on?”

“What was your role?”

“Did the project involve listed building consent?”

“What were the main conservation issues?”

“How did you approach the existing fabric?”

“What did you do when the building regulations conflicted with the historic construction?”

“Have you worked with conservation officers?”

“Can you show me examples where the existing building shaped the design?”

“What did you learn from your previous experience that will help you with this project?”

The answers will tell you a lot.

Someone with real experience will usually be able to talk in detail. They will not just show you glossy finished photographs. They will talk about the process, the constraints, the surprises, the negotiations, the construction methods, the materials, and the decisions that had to be made along the way.

They will also be comfortable saying, “We need to investigate that before deciding.”

And, in many ways, that is exactly what you want.

THE BEST RESULTS OFTEN COME FROM THE CONSTRAINTS

One of the joys of working with existing buildings is that the constraints can lead to much more imaginative outcomes.

A new-build project can offer freedom, but an existing building offers conversation. You are in dialogue with what is already there. The proportions of a room, the thickness of a wall, the line of an old roof, the way light enters a space, the traces of previous alterations — all of these can become part of the design.

Sometimes the thing that first appears to be a problem becomes the thing that makes the project special.

That awkward level change might create a beautiful transition between old and new. A retained wall might give the new work a sense of depth and permanence. A historic opening might dictate a more interesting plan. A structural constraint might lead to a more elegant solution than the obvious one.

This is why working with existing buildings can be so rewarding. You are not just designing an object. You are creating a new chapter of the story.

WHY IT’S WORTH GETTING THE RIGHT ARCHITECT

Employing an architect who specialises in existing buildings is not about being cautious for the sake of it. It is about giving the project the best chance of being successful, and saving yourself from problems and potentially significant expense down the line.

It can help avoid costly mistakes. It can make the consent process smoother. It can protect historic fabric. It can improve comfort and energy performance in a way that is appropriate for the building. It can prevent damp issues. It can reveal opportunities that might otherwise be missed.

Most importantly, it means the design starts from a proper understanding of the building itself.

And with existing buildings, that is everything.

Because the real skill is not simply knowing what to add. It's understanding what you already have.