Firstly, and this is crucial, restoring historic buildings isn’t about making them pretty again. It’s about bringing them right up to date, while retaining all the qualities that make them a genuine heritage asset. And it’s on that fine line that things really get interesting. It’s at this interface that sustainable materials are playing a truly massive part in that delicate balancing act. And, having spent too many late nights worrying about it, I can tell you, that ‘yin and yang’, history and sustainability, isn’t just a nice idea: it’s an absolute necessity.

The Tension Between Old and New

Restoring historic buildings often feels like a tightrope, with tradition on the one side and the future on the other. The first side’s pole is made of original materials, traditional craftsmanship, and historical character, while the latter includes improved energy efficiency, longevity, and sustainability. It’s the tricky tension between past and future that requires careful consideration.

When I first came to work on historic buildings, the notion of using modern, sustainable materials to repair them felt like heresy. How can you use stuff from the future when you have something from the past? Buildings that are hundreds of years old? But beautiful as they are, those old materials often fall short of today’s standards. Brick and stone might look great, but when you don’t have insulation in the walls, they are giant radiators in the winter and ovens in the summer. That’s where sustainable materials come into play and where it starts to get interesting.

Insulating the Past for the Future

Insulation is the biggest issue with restoring historic buildings, as they were built in a time when central heating hadn’t been invented. It wasn’t a priority, and today if we want to make these buildings habitable and energy efficient, we’ve got Sustainable materials are the solution.

For example, insulation such as sheep’s wool is natural, renewable and a far better regulator of temperature and moisture than many of the modern synthetic insulations which don’t breathe, and often trap moisture. Most importantly, it is breathable, and historic buildings need breathability. Damp and mould is the last thing you want in a historic

There’s also hempcrete – a mix of hemp and lime that’s light and insulating, ideal for filling the spaces between old stone walls that led with traditional methods and also carbon-negative – it actually absorbs CO2 while it sets.

Respecting the Original Aesthetic

And now to the issue of aesthetics – because the other major concern people have about using sustainable materials in historic buildings is that they will ruin the look of a place. And I’m right there with them. Nobody wants to have something modern and ugly thrown onto an otherwise beautiful old fa?ade. But here’s the twist: the right sustainable materials can actually add to a building’s original character instead of detracting from it.

Take, for example, reclaimed materials, which are a real blessing in this field. Reclaimed timber, bricks and tiles allow the beauty of aged materials to be incorporated without compromising on sustainability. I once restored a Georgian townhouse where we used reclaimed floorboards that blended in almost imperceptibly with the original wood: the marriage of old and new looked like it belonged there from the start.

Another classic, lime mortar (used in building for hundreds of years) is making a welcome return. Unlike modern cement, it’s porous and pliable – ideal for old buildings that need to slide a little over time. It’s also greener, as the CO2 emissions from the production of lime mortar are far lower than cement’s, and it permits the reuse of existing brickwork, rather than ripping and replacing.

The Green Roof Revolution

One might think that green roofs had been invented for those low-energy, super-insulated eco-homes of the future, but they’re also very compatible with historic buildings. They function well on old warehouses and Victorian terraces alike, and are not only stunning to look at, as they cover the grey urban roofscape with vegetation, but also provide excellent insulation and manage rainwater in a very efficient way.

Because the roofs aren’t visible from the street, they add to the building’s historic appearance instead of detracting from it. At the same time, they offer huge environmental benefits: they absorb rainwater, create insulation from the elements and act as wildlife habitats, all the while reducing the building’s carbon footprint. They’re the old buildings’ secret superpower.

The Future of Restoration is Green

What I have come to understand is that sustainability and historic restoration are not mutually exclusive. two sides of the same coin. Our built heritage must be able to continue into the future, and this requires these buildings and structures to be outfitted with the technology to face the environmental challenges of the present day. And that means that sustainable materials must be embraced rather than eschewed.

Thus, when people ask if sustainable materials should be used in a historic building, my answer is always: of course they should. It is not about a compromise with tradition; it is about making sure that a building has a future as well as a past.

Ultimately, that’s what any restoration project is about: creating spaces that honour history and future.

For further insight, here’s another article on the subject:  https://www.lifeunleashed.co.uk/how-sustainable-architecture-is-giving-new-life-to-historic-buildings/