Tallest timber building in the Netherlands

Laminated Timber Solutions (then known as Korlam) has supplied the laminated timber and all the CLT to construct the tallest timber building in the Netherlands. Patch 22, consisting of housing and commercial units, is under construction in Amsterdam.

Like a Knee Patch

With a height of over 30 metres, Patch22 in Amsterdam-North will be the tallest timber building in the Netherlands. This building consisting of housing and commercial units with a remit to develop the site sustainably. We have discussed the development process with architect Tom Frantzen from architectural firm FRANTZEN en al.

At the beginning of his career, Tom Frantzen mostly focused on the interface between visual arts and architecture. He then transitioned to traditional architecture. In 2005, his working method took its current shape.

In his own words: “Until then, I used to take part in a major design competition once every year. This was also the case in 2005, when I participated in the competition for the design of the Stockholm city library. Over 1000 teams had submitted their designs. That’s when I realised that I only had one chance in a thousand of winning. I compared this chance against the cost of participation. How much did we spend as an architectural firm on competitions? To my surprise, it turned out to be a considerable amount, with only a slim chance of winning and realising the project.

Then I began to develop projects myself, first on a small scale. The money I used to invest in design competitions now went to building projects I designed myself. In 2009, I came across the tender for the sustainable development of Buiksloterdam. The tender was not awarded on the basis of a bid for the plot, but on the basis of a sustainability score. For me this was the signal that I could beat a regular property developer in the tender process.”


Frantzen continues: “Initially we wanted to establish an association for collective commissioning, but we abandoned this project. During the tender process, it turned out that we would have had to draw the building in great detail in order to win. As a result, the association would have had little say in the design after winning the tender. We therefore participated as a property developer and created Lemniskade BV, of which I am a shareholder with Samplaist BV and of which Claus and Margriet Oussoren are shareholders with BAMO BV.”

Lemniskade won the tender and Patch22 became a reality. Where does the name come from? Tom Frantzen: “It comes from Catch22, which refers to a paradoxical situation and in this context to recycling. In addition, the plot or patch we are building on is number 22. We were sure we had come up with a good name when we had to explain our vision for the site during the tender process. We described Buiksloterham as a pair of worn-out jeans. You can functionally repair them by stitching up the holes, but it looks terrible. Knee patches, however, make jeans fashionable. When we superimposed a picture of a pair of jeans on a map of the site, it exactly matched the knees and the canal was the area between the legs.”


Patch22 is a residential-commercial complex built from timber. Why has this material been chosen? Tom Frantzen: “Of course, it sounds amazing if you talk about the tallest timber building in the Netherlands. This has enabled us to attract special people. Clients often tell me: ‘We do not seek to construct timber buildings. They don’t sell.’ But that’s where they are wrong.

The fact that the building is made from timber has proved to be a strong selling point. In addition, timber is a renewable material and is therefore consistent with the cradle-to-cradle principle according to which everything is recycled. Our building is not completely true to this principle, but it does include several aspects. Another advantage is the incredible warmth which timber lends to buildings. And let’s not forget the fact that timber is lighter than prefabricated structures and concrete. This makes quicker and cheaper constructions possible, although the latter has yet to prove itself.”

Six timber storeys, each four metres high, are built on top of a six-metre-high concrete ground floor. The supporting walls, the columns and the frames are made of timber and have retained their natural colour as much as possible. The floors will have a concrete-like appearance. Patch22 has been designed with clean lines, while the warmth of the visible timber gives it an extra dimension.