Balance between refinement and solidity

VERTICAL is the result of a collaboration between five different architects. The architect Chris Collaris uses sustainable, unusual materials; here he explains the ideas behind his design.



Five architects means five styles and five ways of working. Nevertheless, the result of the VERTICAL project is a single, complementary design. In this series, we talk to the architects about the ideas behind their designs and their way of working. Chris Collaris (1981) is one of these five architects. We met up with him in his studio in Ouder-Amstel in Amsterdam.

In his projects, Chris Collaris stands out as a classical architect. His designs are typified by the use of dark, wooden façades and sustainable materials. In the VERTICAL project, he is responsible for the design of two building elements at the base of the building: under the lower tower by the architect Donna van Milligen Bielke, and under the taller tower by NL Architects on the north-east side.

The architect Chris Collaris in his studio in Ouder-Amstel.

Responding to the towers

“For me, the essence of VERTICAL is the diversity of the overall plan. There’s a contrast not just between the two towers, but also within the design of the towers themselves. We thought it would be interesting if the design of our building elements responded to the large volume of the towers. The taller tower is transparent, with plenty of glass. With that tower, we examined how we could create a solid-looking residential block with deep soffits and recesses. With the lower tower, on the other hand, we’re applying a refined, wooden materialisation. This contrasts well with the concrete earth strata in Donna’s tower above.”

Building element under the lower tower by the architect Donna van Milligen
Possible impression of the façade
Building element under the taller tower
West elevation

Wooden façade

“Dark, wooden façades have become something of a trademark for me. A few examples of where I have used these are Woonhuis MM and Saahouse in Amsterdam. These wooden façades are made from sustainable, natural products. With VERTICAL, I’m going a step further. For example, the wooden façade under Donna’s tower will not be coated in colour, but will naturally become grey over time. A coating complicates maintenance, and we can achieve sufficient fire resistance by using a polymer treatment without affecting the colour of the wood. We have chosen a preserved wood variety: Limba. This wood variety ages beautifully, and fits well with Heijmans’ policy of using only sustainable wood. This façade will comply with all requirements, but will appear very natural.”

Chris Collaris at Woonhuis MM in Amsterdam-Noord
With its characteristic dark, wooden façade

Shiny grey

“The Limba wood will really live, and ‘greys naturally’. When felled, the wood is brown in colour. However, it slowly turns grey over time, and becomes increasingly shiny in sunlight. And yes, the wood will also turn green, thanks to the large amount of green in the design, and because a large part of my design is situated on the north side. This is normally a potential weakness, but in fact it adds something to this design.”

Above: Sketch design north side lower tower

Mineral coating

“For our other building element, under the taller tower by NL Architects, we chose a monolithic whole consisting of stacked blocks. Here, we’re working with brickwork. That might sound rather boring, but we’re going to do something really different: we’re attempting to create walls using surplus stocks of bricks. This is cheaper and more sustainable. We’ll then coat the brick walls with a mineral coating: this involves sealing the surface with a light-coloured, opaque coating made from lime. This coating will ensure that the building can continue to ‘breathe’, despite the very strongly monolithic character of the walls.”

“We'll then coat the brick walls with a mineral coating: this involves sealing the surface with a light-coloured, opaque coating made from lime.”

Outdoor space for everyone

“Our design adjoins the green border of the plan. For this reason, we wanted to give every resident an outdoor space. By inserting a horizontal gap of around a meter between our part of the lower tower and Donna’s, we have created an extra space. This allows a greater degree of freedom in the building details, such as window surfaces, voids, loggias and outdoor spaces. However, these aren’t outdoor spaces in the normal sense, but rather loggias with offsets and ‘gardens in the sky’, if you will. They don’t necessarily need to be symmetrical and perfectly uniform. That would be boring. We really wanted to make it human and interesting.”