Jeanne Gang: What architects can learn from grafting

Horticultural grafting, where a new plant is joined to the root stock of the old, is an ancient practice designed to boost crop productivity. What can this technique teach us about architecture at a time of climate crisis? A great deal, according to US architect Jeanne Gang, who developed this pleasing analogy as the premise for her new book The Art of Architectural Grafting.

Gang, who heads a four-office practice with more than 140 staff, makes an eloquent case for the graft of creative re-use as a way to both extend the life of a building and increase its capabilities. The idea came to her when she saw how the process of grafting could enable more plentiful, tastier and more disease-resistant varieties yet was ‘very much about having to work with the constraints of the plant itself, and that reminded me of several of our projects’.

In the resulting book, Gang explores the analogy and sets out her credo for extending buildings ‘to increase their usefulness and delightfulness and reduce their carbon pollution’.  As well as case studies of her projects – some built, some speculative – she considers grafting at the scale of the joints themselves, and, on a much wider, urban scale, applications of grafting in the form of reforestation.

Such a strong concept, she feels, is necessary to help drive change in architectural practice towards greater consideration of re-use over newbuild. In particular, she feels there is a lack of precision in how retrofit is talked about, and that design creativity isn’t always part of the conversation when it comes to reducing embodied carbon.

‘There’s not enough language around the practice of re-use and additions,’ she says,

Gang is passionate about the need to re-use what is there through architectural grafting, with the new additions allowing buildings to not only life longer but to flourish, while saving their embodied carbon.

‘One of the most effective carbon-saving practices – better than just using bio-based materials – is to add capacity to what is already there rather than just re-using the building as it is.’  

But she’s all too aware of the challenges of convincing clients that this is the way forward rather than newbuild.

‘In the US, most of the time clients just want to tear down what’s there because there’s a perception of this approach as easier or less costly. The challenge is to convince them that, as well as saving embodied carbon, there’s a quality you can get by re-using and adding on that you wouldn’t get if you built from scratch,’ she says.

And while re-use isn’t as common as it is in UK and Europe yet, she does detect an increase.

‘It’s becoming more prevalent, so we have to be ready with these concepts and with our approaches,’ she says.

For Gang, this is articulated in her 10-point credo, expressed for the first time in the book and conceived as an approach that could be achieved in different aesthetic ways. These include concepts such as precision of intervention, reciprocity between old and new, and pleasure: ‘A properly grafted building or city will offer users visual and experiential delight’.

Gang is enthusiastic about the potential for ‘wonderful dialogue’ between old and new in ‘asynchronistic collaboration’ with the original architect. As well as engaging with and riffing on the original concept, she talks about anticipating future uses and the idea of the building as an open-ended project.

‘That’s something that no one ever talks about. It’s not just about enabling flexibility, but also imagining that a project is never finished. It’s liberating to my creativity to think about what the building could become, and when you’re designing it, maybe setting up that opportunity for the next architect,’ she says.

Studio Gang has found that the museum sector has provided the most fertile ground for grafting projects.

In Little Rock, Arkansas Museum of Fine Arts, the practice used what Gang calls a ‘grafting mindset’ to both prune back and add on to improve the functionality and life of the building. The project inserted a new organisational spine to link disparate existing elements and provide new social and gallery space to better addresses its park environment. In New York, the practice’s Gilder Center intervention at the American Museum of Natural History improves functionality and visitor flow by creating connections to 10 existing buildings.

The practice is not afraid to be bold with its re-uses, as demonstrated by its speculative project for the Prentice Women’s Hospital in Chicago, a Brutalist design by Bertrand Goldberg. Gang’s design proposed a new research tower rising dramatically above the clover-leaf shaped original.

The book includes several urban-scale grafting projects such as the Beloit College Powerhouse in Wisconsin, a re-invention of a coal-burning power plant. It also explores the wonderfully named ‘bark belt’ concept of urban forests as offering a new way forward for polluted post-industrial ‘rust belt’ land. As well as helping to depollute the site, these new forests could provide the raw materials for mass timber construction.

Studio Gang is currently working on a pilot project for an urban forest, and Gang feels that architects should be involved in such initiatives, which could have community as well as productive benefits.

‘Forests need to be designed, and perhaps architects can be part of that conversation so we can help imagine how these forests can serve different purposes and users. It’s a new form of urbanism.’

In Gang’s hands, what could have been a laboured analogy is engagingly explored, enhanced by personal remembrances and a beautiful book design. She very much hopes it will prompt further discussion by others of this most pertinent subject.

The Art of Architectural Grafting by Jeanne Gang is published by Park Books