Botanical buildings

A joint venture between British consultancies Barton Willmore and Buro Happold recently completed the design for the King Abdullah International Gardens (KAIG) – a giant botanical garden commissioned by the City of Riyadh as a gift to King Abdullah of Saudi Arabia to celebrate his accession to the throne.

Taking a subtle new approach to the creation of a botanical garden in an arid climate, KAIG aims to “explore, demonstrate and portray the great paleobotanical ages that have swept across this land.”

In fact, the KAIG design and use of organic material is so cutting-edge that Barton Willmore and Buro Happold won an international competition in 2007 to claim the right to design it and now, having completed the design with advisors from the UK’s National History Museum and Eden Project, KAIG is about to go to tender.

Barton Willmore provided master planning, architecture and landscape design services while Buro Happold provided project management services, structural and building services and infrastructure engineering design, as well as a range of specialist consultancy services.

The JV team was also responsible for the design of KAIG’s infrastructure, which included earthworks, roads, footpaths, and coach and car parks, along with an energy centre, sewerage treatment systems and services such as electricity, telecoms, gas and water.

Sustainability
KAIG will be set within a 160-hectare site in an arid desert site within the KSA Central Region and, as a cornerstone of the City of Riyadh’s growth plans, will provide a new destination for KSA nationals and international visitors.

Visitors will be able to walk amongst plants, trees and flowers which lived over 400 million years ago, as well as a range of external gardens which will include a maze, butterfly enclosure and aviary.

“Indeed, this project epitomises our desire to marry manmade structures with the natural environment and produce a broader narrative about their complex interrelationships over time,” explains Nick Sweet, project director and partner in charge of urban design at Barton Willmore’s London office.

“I hope that KAIG will become a world-leading focus of mankind’s understanding of the process, consequence and study of climate change, capturing and displaying extraordinary ecotopes from history and from the present day, and presenting the choices that are available to us.”

The project’s centrepiece will be a ‘paleobotanic’ building formed by two adjoining crescents that will rise 40m in height. The building’s roof, which will be the largest ETFE-covered structure in the world, will span up to 90m. KAIG will also feature an array of specialist tensile, pneumatic and grid shell structures.

KAIG will also showcase sustainable development by incorporating renewable and low energy technologies. It will employ thermal ice storage and black and grey water recycling systems, with underground reservoirs for storage and, with the outside temperature reaching up to 50°C, this approach will be vital to the control of the different historical climates inside the various gardens.

“KAIG is just one example of where we are working closely with a partner to create a new type of sustainable community,” explains Sweet.

Form and structure
The design of the main crescents utilised state-of-the-art 3D modelling and design tools, with the structures developed parametrically and optimised to suit both the structural and architectural constraints.

“While we have extensive experience in the design and construction of cutting-edge projects in the Middle East,” says Jerry Young, project principal and partner at Buro Happold, “the design of KAIG has been extremely challenging because nothing as complex has been built on this scale and in this kind of environment before.”

The base of the crescents is comprised of a series of 8m high reinforced concrete frames that vary between 55m and 75m in length.

Each supports an overlying structural steel arch roof structure, which is broken into segments for thermal expansion. Both thermal expansion and long-term shrinkage effects were major considerations in the design, and considerable effort has been put into minimising the number of movement joints required.

The main crescents will house an auditorium, VIP facility, ticketing buildings, a childcare facility and mosques.

In addition, to provide amenities for visitors, six watch towers and five toilet buildings are included. The ticketing structures have structural steel umbrellas that support a fabric covering.

These shade structures provide and impressive first impression to and are over 7m in height. Other buildings include a single storey management and maintenance facility, a nursery shade structure, a fire control centre, a 150m² energy centre, as well as external specialist garden spaces.

Walking through time
Starting in the Devonian period, when plants remained at knee height, visitors will travel through the Carboniferous, Jurassic, Cretaceous and Cenozoic gardens before reaching the riverbeds and light woodland of the Pliocene period.

Finally, they will enter the ‘Garden of Choices’ where they will be presented with scenarios related to climate change and important choices necessary for the future.

“The proposed master plan for the KAIG scheme presents the idea of a single, clearly understood, iconic form as the central defining feature of the scheme. The botanic garden requires shade and sun control to ensure that a broad palette of plants can be displayed,” explains Sweet.

“In order to accommodate the possibility of phased development, the structure is formed in two crescents, which combine to form a single crescent, already an iconic form, which also responds to the need for a simple, clearly understood pedestrian circulation system.

Sweet adds: “The crescent forms thus become both a focus and an organising device for the overall scheme, with the central promenade dividing the exotic interpretive enclosures from the arid environment of the wadi garden. Axial links connect the broader proposal and radial links connect these, ensuring the option of a broad range of local ‘loops’ to visitors, who may come to the site for one reason, yet stray into other elements of the scheme, to their delight.”

The final word
Both Buro Happold and Barton Whitmore are quick to point out the importance of collaboration in bringing KAIG from the sketch room to becoming a conceptual rendering that is ready for tender. “There has been almost zero repetition during the design process and the end result has been achieved through a truly multi-disciplinary, collaborative and innovative approach,” explains Young.

Moreover, providing a structure and an internal environment that meets the requirements of such a broad range of plants is an incredibly difficult feat and, during design, presented a considerable challenge to all those involved.

Achieving such a cutting-edge design alongside a botanical garden of the calibre planned for KAIG is testament to the skill of the individuals involved, as well as a very forward-thinking client.

World’s notable botanical gardens (in no particular order)

• Berlin Botanical Garden (Germany) – 3 million specimens
• National Botanic Garden (Belgium) – 3.5 million specimens
• Komarov Botanical Institute (Russia) – 7.2 million specimens
• Kew Gardens (United Kingdom) – 7 million specimens
• Harvard University Herbaria (USA) – 5 million specimens
• New York Botanical Gardens (USA) – 7 million specimens
• Missouri Botanical Garden (USA) – 5.8 million specimens
• Royal Botanic Gardens (Melbourne) – 1.2 million specimens
• Royal Botanic Gardens (Sydney) – 1 million specimens