Several years ago, Artist, Katie Paterson was commissioned to create a public piece of artwork by producer, Situations, for the University of Bristol’s Life Sciences building. Katie knew she wanted to create a piece of artwork that encompassed the world’s tree life, and to work with the scientists within the department to realise the work. The artwork went through a number of stages before becoming what it is today – ‘Hollow’.

“Hollow is a piece of artwork, a sculpture, a piece of architecture, an immerse place and an idea,” commented Katie. “It is a place to enter into; a collaborative artwork conceived together with myself and Architects, Zeller & Moye, and will exist in Bristol for decades to come.”

Inspiration

Hollow is brought together in a form that represents a miniature forest of every forest on earth. The outside posts are similar to heavy tree trunks and the interior represents stepping inside the hollow of a tree; an intimate, yet expansive place.

The multitude of trees are brought together in a numinous interior space, with dense clusters of wood – containing twigs collected from the floor of sacred places, to the oldest living tree on earth – surrounding visitors.

Katie envisioned bringing together an entire planet of trees into one space and, together with Zeller & Moye, collected nearly every known tree species and collapsed them together in microcosm.

Collaboration

It became clear to Katie through the research and development process that she was hitting a brick wall when it came to envisioning the form. She explains: “I work with ideas, and physical things, but not three-dimensional space. That’s when I approached Zeller & Moye, and the project really took off.”

Zeller & Moye was able to work with the idea of the ‘miniature forest’ and take it to an entirely new place; an immersive form that visitors could enter into. Together the duo looked at grottos, caves in the landscape, crystalline underground structures and Zen gardens – a landscape miniaturised.

Hollow went through a number of design phases before becoming what it is today – an intimate space that surrounds the visitor physically and through their imagination and senses.

Scents, colours and origin

The core of the artwork was to bring together tree life from space and time; to encompass the globe. Hollow contains species from almost every country on earth. Fossils have been embedded in the floor area, which go back over 400 million years to a time when the first forests began to grow.

The scent inside Hollow is transporting, and the colours and textures are vibrant. Specifiers can gaze into the intricate clusters of wood, through the stalactites and stalactite forms, through the dappled light that mirrors a forest canopy. The beauty of Hollow is its ability to subtly change from day to day and season to season.

Every single piece of wood was meticulously catalogued before construction. Visitors to Hollow will soon be able to visit Hollow’s website and explore all the 10,000 species – their names, origins and stories.

Internal design

The inner space is like a capsule inside the raw shell. The two layers are disconnected by an air cavity and a protection layer keeping the inside safe from the weather. In addition, a large wooden block can slide out to close the opening during night time.

Internally all the wood is in its natural state – the exterior Douglas Fir and all 10,000 interior pieces. The floor has had a light natural oiling, to protect it from the numerous footsteps over time to come. Otherwise, it was very important to leave the wood as it is, directly from the tree.

Around 90% of the wood collection arrived in the standard ‘International Wood Collector’ dimension – around the size of a pocket book. The duo squared off and sanded every single piece, the larger logs were cut to mirror these shapes and sizes, with profiles ranging from 9 x 9mm to 400 x 400mm.

The process

Zeller & Moye went through a three-year design process with Katie. The duo began with one design, but half way through the process they noticed that the majority of the wood pieces that they had been collecting through donations were much smaller than they expected. Zeller & Moye explains: “As the wood collection started growing, the dimensions of the wood pieces changed the design and led us to shrink the project to half of the original.

“We found the idea of the stalactites and stalagmites very successful as an arrangement for the wood pieces all around the interior cave-like space.”

Since the beginning, the duo had clear visions that the woods should be displayed in their natural form, without the application of any finish or treatment. The duo aimed to maintain original colours, textures and smells of each piece.

“Hollow will slow down a visitor by stimulating their five senses,” explains Zeller & Moye. “Similar to walking through a forest dappled with light, it allows visitors to see the huge diversity of tones without the use of artificial light.”

Instead of aiming for a fully sealed shell, the duo accepted that wood is a natural material that will grow and shrink throughout the year, the colour will fade to elegant silver, and the northern face might potentially grow moss over time. Hollow should gradually become more and more part of the park landscape.

The complex assembly of the thousands of woods has been arranged as a compressed space of only 2m2, just enough for one or two persons to enter allowing for an intimate experience with the natural material.

Composition and production

In order to understand the complexity of the interior, the duo worked with a detailed 3D model containing the 10,000 pieces of wood. This model was the guide for the construction process until the completion of the piece.

The outer composition, that resembles a miniature forest, occupies the entire so-called ‘Alcove’, an area of 300m2. The majority of Hollow, and especially the interior, was prepared and assembled offsite in a workshop. It was craned in place in just half a day, followed by the individual posts of the miniature forest being installed onsite.

Hollow has come about through a rich collaborative experience between Katie Paterson and Zeller & Moye and their incredible vision of mapping these ideas into space.