Sibylla Hartel, Partner - Gustafson Porter + Bowman

Hello Sibylla,

To begin our conversation, Gustafson Porter + Bowman was one of the founding members of a movement called UK Landscape Architects Declare. Can you tell us what the aims of this initiative are, why you got involved, and how you feel those aims are already reflected in the ethos of your studio?

The initiative was set up to raise awareness of and address the challenges of climate change and mass biodiversity loss. As a signatory, we have made a pledge to advocate for faster change towards resilient design practices for the benefit of the natural, social and economic systems that we are part of. Wellbeing, recycling, re-use, biodiversity and accessibility are at the heart of what we do. 

One of Gustafson Porter + Bowman’s most high-profile projects to date is the landscape re-imagining around the site of the Eiffel Tower. One part of the design, the Trocadéro Gardens, became home to the Champions Park during the Paris 2024 Olympics, immortalising it in the minds of millions around the globe. What elements of the project have made it so successful, and what was it like to see it up in lights on the world stage?

When designing for a site that is visited by millions of people each year, it is important to design a space that is very robust. This had to be balanced with respect for the historic character of the gardens, the historic water feature and the sloped lawns, which are all on an axis with the Eiffel Tower. To discourage people from trampling the sloped lawns and causing compaction and erosion, we designed large-scale limestone blocks as benches at the top and bottom of the slopes. These linear bands of stone, along with rows of trees, shrubs and rose beds, reinforce the perspective toward the Eiffel Tower, with planting diversified for increased biodiversity. This has been successful in creating gathering spaces where people can picnic, meet friends and family, and admire the historic views of the Eiffel Tower and the Fountain of Varsovie. 

It was wonderful to see the site we know so well have such a prominent presence during the Olympics. During the games in the summer of 2024, the whole area, including the fountain, was covered with scaffolding for the grandstands for dignitaries and guests during the games. We are now in the process of restoring the lawns and completing the rose planting post-Olympics. The site should be open again by June this year (2025). We are all very proud of the project and look forward to the public being able to enjoy this iconic landscape. 

“We have made a pledge to advocate for faster change towards resilient design practices for the benefit of the natural, social and economic systems that we are part of”.

Another major transformation project is that of Taikoo Place in one of Hong Kong’s most prominent business hubs. How have your designs ‘humanised’ the public realm around its two central office towers? Do you have a favourite aspect?

Despite its proximity to the natural world, wedged between mountains and the sea, central Hong Kong has few high-quality biodiverse green spaces for people and fauna. Taikoo Place creates an inclusive and accessible open space with lush native vegetation and sculptural water features. Two office towers were demolished to create this open space. 

The water features are beautifully detailed - we modelled them using 3D software, with the big stone pieces CNC cut from the 3D files.  The water flows over the textured pieces and creates a focus and an ambience – fast-paced in some areas, languid in others. 

But what I truly love is the lushness of the vegetation. When you are in the space, you feel completely immersed in vegetation; you hear bird song everywhere. To create shade, we planted densely, with many trees. Most of those trees are native, grown from seed collected from Feng Shui woodland species specifically for the project in a local nursery, overseen by our local landscape executive consultant, Urbis, and supported by our wonderful client. 

“When you are in the space, you feel completely immersed in vegetation; you hear bird song everywhere”. 

Feng Shui woodlands are remnants of native woodlands which were protected from agricultural clearances due to their spiritual significance. These native trees are great for biodiversity. To raise public awareness of Hong Kong’s heritage of Fung Shui woodlands, all trees have name plaques with QR codes that provide further information. 

The space is very popular with both people and birds. It is packed with office workers during lunchtime and used for events in the evening. Less expected, but hugely rewarding, was seeing older people, many of whom were in wheelchairs, being brought by their carers to sit by the water and listen to the bird song.

“Less expected, but hugely rewarding, was seeing older people, many of whom were in wheelchairs, being brought by their carers to sit by the water and listen to the bird song”.

In 2013, Gustafson Porter + Bowman was commissioned to redesign the famous Chelsea Barracks in West London and has since led the development of six phases of the 12-acre site. Phase One officially opened to the public for the 2019 Chelsea Flower Show. Can you describe how and why you chose to reverse the historic idea of ‘social interventionism’ at this iconic site?

The eighteenth-century idea of social interventionism is epitomised by garden squares with railings around them that exclude the public. We wanted to open up the spaces to make them truly public, fully accessible and permeable. Rather than exclude the public from a high-end residential neighbourhood, we wanted to invite people in so that everyone could enjoy the beautiful and biodiverse gardens that we designed. Having access to good quality green spaces is so important for people’s mental health. It was important to us that anybody could enjoy the woodland walk, sit by the water feature, or explore the productive gardens planted with fruit trees, herbs, vegetables and beautiful cut flowers. In an inner-city area, it is important that children can experience how fruit and vegetables are grown.

“Having access to good quality green spaces is so important for people’s mental health”. 

In Valencia, Spain, Gustafson Porter + Bowman is creating an inviting urban oasis with its Parque Central project. The area was once characterised by its railways. How are you weaving this heritage into the modern-day park?

Until now, the railway has divided the city in two, either side of the tracks. The park aims to create connections for pedestrians between neighbourhoods through the park. The railways moved not only people but also goods to and from Valencia. 

The city and surrounding landscape are abundant in fresh fruit and vegetables, seafood and rice. The Valencia Central Market is wonderful. We celebrated this abundance with the concept of ‘bowls’ as Valencia also has a rich history of ceramics. We sculpted the flat railway ground using earth movement and retaining walls to create a series of bowl-like gardens which contain different programmes. 

These include a ‘huerta’ [vegetable garden] with fruiting trees, vegetables, and herbs that one finds in the surrounding agricultural landscape, as well as play areas for children and climbing walls for adults. 

We analysed the character of each of the neighbourhoods, and this informed the programme for the park. Many of the existing railway sheds were dismantled and re-erected on the perimeter of the park where they could be used for community uses. These include a new sports centre, community centres, restaurants, cafes, and a garden centre.

Moving on to Marina One in Singapore, you worked alongside fellow Tenderstream member Ingenhoven Associates to create the ‘green heart’ of this breathtaking mixed-use scheme. How have you used soft and hard landscaping to help unify the different uses of Marina One to such a striking effect?

Ingenhoven Associates had developed the masterplan concept of an organically shaped green heart in the centre of a rectilinear block of commercial and residential towers. Our design for the green heart creates a lushly planted landscape in the central courtyard with tropical planting and waterfalls integrated into shade louvres tumbling into a reflecting pool. This landscape creates a magical, restful entrance to the office towers and residences and is fully open to the public. The open courtyard also helps to bring natural ventilation into the heart of the development and light to the internal elevations. 

The green heart is used for many activities and events, such as yoga classes, fashion shoots, parties, and public events. As you move up the building, the landscaped areas become more private. We designed the pool and sauna areas to be surrounded by planting, and there is even a small mini-golf area, yoga platforms and children’s play area. Restaurants are accessible to the public on the upper levels, all set in a richly planted landscape. 

We hear you’re through to the final seven shortlisted concepts in a design competition launched during the summer of 2024 by the London Festival of Architecture and Wandsworth Council. The brief (which appeared on Tenderstream in August) was to transform the public realm underneath Battersea’s Falcon Road Bridge. Can you tell us what your designs envisage for this space and why?

Our design was inspired by the Falcon River that once passed through the site. The idea of flow and movement is expressed in the design of the landscape, the cladding of the tunnel and in the lighting design. The landscape design aimed to create better connectivity between the station, the tunnel and the surrounding neighbourhood through additional tree planting and the restoration of the Falcon Glade gardens. 

We also framed the north and south entrances to the tunnels with colourful climbers and creepers to create a more welcoming, biodiverse environment. The tunnel design took the oral histories (The River of Words) of many of the residents and community groups within the borough. We inscribed these onto the cladding of the tunnel, which also served to waterproof and improve the acoustics of the space. The overhead lighting used bands of gently curving LED lights, which reinforced the concept of flow and movement inspired by the lost river.

Are there any other exciting new projects in the pipeline for Gustafsen Porter + Bowman that you’re at liberty to share with us?

We recently completed competitions in Hungary and Saudia Arabia and are looking at opportunities in Hong Kong and China in addition to UK competitions. We are fortunate to have built up an international portfolio over the years and very much enjoy working in a variety of contexts, cultures and languages alongside our local collaborators and our wonderful clients.

Is there any one project you’ve personally worked on since you joined the practice in 2000 that is closest to your heart?

I love them all, and it feels a bit mean to single any one out, a bit like selecting a favourite child. Swiss Cottage because it is a public park and the first project that I worked on as a project architect for Gustafson Porter + Bowman when I joined 25 years ago. More recently, Taikoo Square – the local team- was such a pleasure to work with, and the results are stunning.

We’re curious what led you to study landscape architecture at Greenwich University in London. Where does your extensive botanical knowledge stem from? Did you enjoy nature and gardening as a child?

I have always loved plants. When I was seven, my parents gave me a six-book gardening encyclopaedia, which I devoured and daydreamed over. I grew up on the edge of town, near fields and nature reserves. I spent a lot of time outside, looking at plants, their contexts, and how and where they grew. I came to London [from Germany] when I was 18. I only intended to stay for a year but ended up studying graphic communication and, eventually, landscape architecture at Greenwich University. If I had known that landscape architecture existed when I was 18, I would have studied it straight away. 

What would your ideal weekend entail (aside from work!)?

My ideal Saturday would start with breakfast in bed, followed by a visit to our local farmer’s market. It always takes ages as we end up meeting and chatting to neighbours. In the afternoon, I will often meet friends for an art exhibition, with my partner joining us for drinks or a meal. 

Sunday is usually up early, and either a long run or a gravel bike ride with my partner, often in the Surrey Hills, sometimes that gets combined with a visit to a historic garden, followed by pub lunch or dinner.

Lastly, as a loyal and valued user of Tenderstream, what makes the service helpful to Gustafson Porter + Bowman?

Tenderstream's service is of great value to Gustafson Porter + Bowman. The daily global project leads and competition announcements help us stay up-to-date with new opportunities. Having everything in one place saves a lot of time. The tailored ‘daily list of opportunities’ is especially useful in guiding our New Business efforts.

Thank you.

Interview by Gail Taylor, Features Editor