‘Making buildings sing’ – a panel on timber retrofit and reuse

After three days displaying the Wood Awards shortlist exhibition at gallery@Oxo on the Southbank, TDUK hosted a live talk as part of the Material Matters programme of sessions exploring material intelligence with architects and designers.

Responding to Material Matter’s overarching concern with the reuse of waste materials and the sustainable use of bio-based materials, Wood: How to Retrofit and Reimagine took as its focus the reuse of buildings themselves.

Wood: How to Retrofit and Reimagine panel discussion with Andy Heyne, Kelly Harrison, Brigitte Clements, chaired by David Hopkins

Held on the top floor of the Bargehouse, a former factory now used as an exhibition space, the talk was delivered by three timber retrofit experts exploring their visions of a low-carbon built environment centered around making the most of existing buildings.

As the discussion unfolded, the atmospheric industrial setting, filled with intriguing evidence of its former lives and now a catalyst for creativity, provided a powerful demonstration of the sensory richness and poetic potential of adapted buildings.

Andy Heyne, director of Heyne Tillett Steel, Structural and Civil Engineers known for using timber to retrofit and extend industrial buildings to create offices (including their own), kicked off the session on a positive note: the demand for reuse is there!

People are, it seems, increasingly seeking out the character of existing buildings.

Using Heyne Tillett Steels’ own timber-extended home at 16 Chart Street (see top image) as an example, Heyne explained that, although originally designed as a proof of concept, the lasting story of the project has been the positive effect on staff retention.

“There’s real value in keeping existing buildings,” he explains, “and clients know this. The better question now is why not keep a building?”

The new top floor at 16 Chart Street – Heyne Tillett Steel and Ian Chalk Architects © Edmund Sumner

And sometimes, he notes, there are good reasons – even in terms of extra carbon – if the building has bad bones. However, he emphasizes that, in his experience, this is rarely the case, and the combination of commercial and structural drivers favoring retention typically delivers the optimal solution.

Why wood?

Describing her journey to becoming an expert in timber structural design and retrofit, director of Whitby Wood Kelly Harrison conveyed the deep satisfaction that she experienced in first combining timber engineering with existing buildings. “When you start working with timber as an engineer, you become addicted…add this process to an existing building and it becomes incredibly rewarding.”

“Over the years, as awareness of the climate crisis has become more prevalent, we’ve since come to realize that timber retrofits are by far the lowest embodied carbon approach.”

Brigitte Clements, founder and managing director of LOKI, an architect-developer with a focus on creating sustainable and socially equitable systems of home-building, laid out why there is no equal to timber as a structural material in retrofits. “It’s a high-quality product that doesn’t need finishes on top, and it’s also really light, meaning that you can add more floor space without needing to strengthen the existing building.”

“It’s beneficial, not just for the wellbeing of the inhabitants, but the onsite constructers as well.”

Financial barriers

Reconstruction and refurbishment to Battersea Arts Centre Grand Hall – Haworth Tompkins, Heyne Tillett Steel

Despite the increased societal awareness of the urgency in retaining and reusing existing buildings, the panel reflected on what the barriers still are and how they are being, or could be, overcome.

Here, Clements spoke persuasively about the need for policy change. “Currently it is usually still cheaper to demolish and rebuild. We need to petition for a policy that at least reduces the VAT on reuse and retrofit to make these projects more financially viable.”

On top of this, she explains, timber carries a perceived risk which brings premiums, meaning that developers have to put a lot more skin in the game to get timber retrofits over the line, making them the preserve of the die-hard eco-committed.

In order to achieve the wide-scale retrofit-first approach that we need, Clements suggests that a reversal in priority is needed: a cultural transformation and change in perception. And she is clear that the first step towards this is the money.

“It’s a blindspot”

Another necessary step, although of a quite different nature, reflected upon by the panel, is a shift in how retrofit is seen within architecture. Describing the absence of any retrofit projects when she was a student “during the era of the star-chitect”, Clements insists that we need to embed the idea of “how to make things sing, by bringing out their character” into our university education programmes.

Brunel Engine Shed by Hawkins Brown and Heyne Tillett Steel. Mass timber is used to recreate the original form in new material © Simon Kennedy

Harrison and Heyne pointed to the great creative potential opened up by adaptive reuse design. Rather than restricting the vision of the architect, Heyne described how extensions provide great opportunities to create striking contrast between old and new, whilst ‘back to frame’ reuse projects allow for transformative reinvention.

Harrison, likewise, vividly laid out all that there is to gain in the creation of sustainable buildings and intimate spaces that speak to us about our history whilst responding to the depth and complexity of the climate emergency.

After generously sharing their retrofit knowledge and insights, the three speakers took a range of stimulating questions from the engaged design audience, ranging from how to balance heritage preservation with energy performance, to the potential for use of timber foundations.

A valuable conversation to be continued!