Saving heritage – the sustainability argument

By Michael Kelly

Erskine College Main Block (1906), Island Bay, Wellington, under demolition, October 2018. Photo: Wikipedia.

Moral and emotional arguments for saving heritage can only go so far; there are many people who feel no particular attachment to the past and act accordingly. But what if there was a way to completely rethink how we manage old buildings that allows us to drastically cut CO2 emissions? After all, most people acknowledge the massive threat that climate change poses. The answer is pretty simple really and it could save most of our built heritage.

To help save the planet, we have to make a fundamental shift in our attitude to the materials already in our building stock. And that shift is to regard buildings and the materials in them as non-expendable – essentially reusable and recyclable. Construction debris makes up 50 per cent of all waste in New Zealand. In the United Kingdom it is as much as 63 per cent annually. Those are finite resources gone forever.

The building industry has a sky-high carbon footprint. The use of concrete is one of the biggest culprits, along with steel, but forming any new material generally carries a large carbon footprint. We extract finite resources out of the ground, use huge amounts of energy to turn them into building products and more energy transporting them and putting them together to form something new. Quite simply, erecting new buildings is catastrophically bad for the environment. (Building roads produces huge CO2 emissions, but that’s another story.)

So, the first principle of sustainability should be, do not demolish buildings. Refurbishing should be the default position for any building no longer needed for its original purpose. Refurbishment is not a carbon-free option of course but it’s many magnitudes better than to demolish and start again. Not all buildings can be refurbished for the same or similar use or even a compatible use and the further you get away from that, the greater the loss of fabric, including, of course, heritage fabric. Building fabric gets tired or worn out, so some replacement will be necessary.

Saving every heritage building is a laudable goal, but it may not be feasible to save every old building. The next step down is to deconstruct a building but then reuse most of its material in a new building. The worst thing that can happen to a building is to be turned into demolition rubble. In New Zealand, a significant amount of construction material is recycled (and turned into a less valuable product) but what is being proposed internationally goes far beyond that. A movement has begun in Europe to institute ‘materials passports’ for new buildings so that every component of a new building gets a digital record and can be identified and re-used, mostly for the same purpose, at a later date in a new building. Think of it as if the components of a building are on loan for a particular purpose and then when they have done their bit, moved on to another building. It’s not quite saving heritage, but, again, at least it’s better than demolition.

The challenge is to convince people that the materials bound up in an existing building have a value; that keeping them will significantly reduce building costs and will help the environment. A campaign in the UK called RetroFirst, run by the Architects’ Journal, champions refurbishment over demolition and rebuild. One of its targets is a peculiar anomaly in VAT (the equivalent of GST) that taxes refurbishment of a building at 20 per cent but exempts new building.

In a country like New Zealand where the relentless pursuit of the bright, shiny and new still holds sway, it would take a major cultural shift to achieve such an approach, but it’s essential if we are to survive on Planet Earth.

Michael Kelly is President of PHANZA, the Professional Historians’ Association of New Zealand/Aotearoa. Republished with permission from Phanzine vol. 26 no. 1 (May 2020).

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