AMFORA, Amsterdam

Looking for new space

Looking at Amsterdam from the air, it is striking how the historical centre and the surrounding 19th century area is crisscrossed by canals, on both sides of the river Amstel. The water covers an enormous surface area, roughly a million square meters. In collaboration with the construction company Strukton, the architectural studio ZJA developed a plan in 2010 to house the urban facilities needed to make Amsterdam futureproof under the water’s surface, thus utilizing that large area of the inner-city canals in a safe and smart way.

This plan is called AMFORA (Alternative Multifunctional Space Amsterdam) and uses the possibilities of underground construction to create extra space for the development of the city and to minimize the impact of cars and their pollution. Excavating the space under the canals creates extra space aboveground as well: for cyclists, pedestrians and parks. Crucial added value comes with the reinforcement and renovation of the quay walls of the canals, which have fallen into dangerous disrepair and are in need of costly repairs. Infrastructural cables and pipes are accommodated in an accessible way that simplifies maintenance. Furthermore, heat/cold exchange installations harvest energy from the difference in temperature with the underground environment.

How can it be possible?

As is well-known, the ground under the city of Amsterdam is wet and waterlogged until about sixteen meters deep, where it rests on firm sandy soil. Every building needs a great number of piles driven into the soil to solidify its foundation. For this reason, Amsterdam is known as the city on piles. The design for AMFORA does not require piles to be driven into the underground, nor sheet pile walls to be driven down to the sand. In order to create up to 18 meters depth of underground space, the so-called slurry wall technique is used: a grab crane digs away the soil and the trench it creates is filled with concrete, which is poured in with a hose from the bottom up. Thus, a sturdy wall that supports the underground space is made.

As soon as the top two underground stories are completed, the water that was temporarily pumped away can return into the canal, above the underground space. Subsequently, the other four levels can be dug out and constructed. In this manner, tennis courts and basketball courts can be created under the river Amstel, or extra theatre halls and cafes for Carré, or a shopping mall and a cinema under the Blauwbrug.

A vibrant healthy city

By making the inner city accessible to cars mainly underground, opportunities arise to make the city more open, vibrant and green. A lively dynamic can be created between the neighbourhood aboveground and the new facilities underground.

In the AMFORA design, the underground world is as closely interwoven and connected with the existing city as possible. Underground, bridges also serve as points of reference, while projections of landmark buildings show the way and various lighting arrangements marks different urban zones.

On the Amstel

Where the River Amstel flows through the old city centre, many functions are performed at street level that might be better placed underground. Think of storage, garages, workplaces and technical installations. Space would thereby be created for the hospitality sector, shops, and appropriate facilities that are currently missing.

Artis, the Hortus Botanicus, Carré Theatre, the Stopera, university buildings, famous hotels and museums all lie a short distance from this part of the river. The reduction in car traffic and increase in underground parking alone would make an immense difference to the streetscape. But underground spaces, which could be built as many as six levels deep, also provide nearby institutions with opportunities to expand. They might include archive space for the Dutch National Bank, additional lecture theatres for the university, another foyer at the Carré Theatre, or more conference rooms under the Amstel Hotel. There might also be a shopping centre, a cinema complex and tennis and padel courts, or a gym.

Transport and energy

The part of the Amstel where AMFORA could be made a reality lies right between two metro lines, the Noord-Zuidlijn and the Oostlijn, and might easily serve to connect the two. It could include a people-mover system, linking two stations underground.

AMFORA has been designed as an energy-neutral project. The newly built space and the use in it of what is known as concrete core activation could take both the underground facilities and the buildings above ground a big step towards sustainable energy use and the cooling of the city. Concrete core activation is a technique in which the capacity of concrete to store heat or cold is exploited by means of built-in water pipes.

The design of the experience

The large scale of the underground development of AMFORA necessitates careful consideration of the spatial experience of its users. Poorly organized, dimly lit and low-ceilinged spaces underground have a disagreeable effect. Nobody wants to feel they have ended up in an underground labyrinth. So in the design everything is focused on clear views and orientation. Dead-end spaces are avoided, while openings offer a view of several levels and consolidate visitors’ natural sense of direction. The choice of lighting, colours and materials is even more important than in a building above ground. High-quality materials, such as stone and stainless steel, and the use of green contribute to a pleasant feeling for anyone using the six underground levels.

AMFORA fits right into urban policies and goals that strive for a greener, healthier and more liveable city. As the city continues to warm up, AMFORA contributes to climate adaptation and urban comfort by providing energy-efficient cooling. It contributes to a future city with vibrant and comfortable public spaces, where accessibility and the transport of goods are not an issue. On the contrary, it actively makes space available that is economically attractive and entirely flexible to meet the needs of the future.