Tallest grain silo
Swissmill Tower
118 metre(s)
Switzerland (Zurich)

The tallest grain silo is the Swissmill Tower in Zurich, Switzerland. This massive storage building is 118 m (387 ft) tall and can hold up to 35,000 tonnes (38,580 tons) of grain. It was designed by architectural firm Harder Haas Partner (CHE) and built for Swissmill (part of the Coop Cooperative) between spring 2013 and April 2016.

This massive silo was built to replace the existing silos on the site, which were in a poor state of repair and had insufficient capacity. Because the mill complex is located in downtown Zurich, expanding outwards was not an option, so the Swissmill decided to go up.

Building the silo was a major engineering challenge as the site is very small, bordered on one side by the Limmat River and adjacent to a major railway bridge. Consequently, the construction of this enormous and incredibly heavy building (it weighs 80,000 tonnes empty) had to be completed without creating a significant seismic disturbance. To achieve this, the building stands on pilings that are 1.2 m (3 ft 11 in) in diameter, 40–45 m (131–147 ft) in length and reach all the way down to the bedrock.

To add to the difficulty, the only spot where it could be built was the site of the existing 42-m (137-ft) silo 57, but this existing structure was essential to the operation of the mill. As shutting the mill down for three years was not an option, the new silo was designed to almost completely envelop the existing structure, with massive supporting columns being raised on either side and then the additional floors built over its roof.

The architects opted to make no attempt to disguise the building's industrial function, leaving it as a windowless concrete monolith that towers over the Limmatstadt neighbourhood of Zurich (it's also the second-tallest building in the city). As a result, it has divided opinion among the city's residents. Some appreciate its brutalist simplicity and the fact that it represents an industry that has chosen to remain in its historic home, but others regard it as an eyesore (one article, published shortly after its completion, described it as "118 metres of ugliness").

Various proposals have been put forward since its completion for ways of softening its appearance – including covering it with plants, fake windows or even Europe's highest climbing wall – but so far it has remained unadorned. Its sole non-industrial feature is Swissmill's glamorous modernist boardroom, installed on the very top floor.