On the site, we joined Mitch van der Hoek, who has worked for construction company and project developer VORM for 18 years and is the foreman for Stepstone. ‘On top of foundations consisting of 151 bored piles, we’ve built the ground floor and first floor in the space of seven months since the start of construction in April 2022.’ But the day of our visit to the construction site, located in Gustav Mahlerlaan and between the A10, Parnassusweg and Amstelveenseweg, turns out to be something of a special occasion: today is the day that VORM is beginning to apply the prefab components to the façade. And that’s when things start to speed up. ‘Erecting each floor takes around six working days. That involves positioning the support structures, balconies, façade panels and window frames. A quick calculation reveals that it’ll take six months to add another 20 floors.’
Social rental housing
The 216 apartments, commissioned by the Lieven de Key Housing Association, will vary from 25 to 60 m² and are intended for first-timers up to the age of 28. They will then need to move on after no more than five years to make room for new first-timers. As we walk into the entrance, it is not immediately obvious that this is being built for people with only limited resources. ‘The first thing you see is a double-height entrance hall followed by the double glass lift’, says Van der Hoek. ‘That gives you some indication of the building’s grandeur.’
Parking for cyclists and scooters
As we walk towards the stairs to the first floor, we pass the place where the De Key lounge will be, a communal area where residents can work or organise events. ‘And what you can see here’, says Van der Hoek pointing to a short, concrete ramp leading to a mezzanine floor, ‘is a two-storey bicycle storage facility.’ It is also the only parking place in the building: for bikes and scooters. On the roof, there will even be sports facilities for the residents. But the Stepstone, designed by LEVS architects, will have no space for cars. There will also be a large courtyard garden and the building will be connected to a thermal storage heating (WKO) system shared with The Pulse of Amsterdam for its heating and cooling.
WKO explained (in Dutch)
Calm and well-organised construction site
Arriving on the second floor, still without its ceiling, we ask Van der Hoek about the challenges involved in construction. They clearly do not include the collaboration with all the partners, such as the commissioning authority, architect and suppliers – that is running smoothly. ‘That increases the likelihood of success, but also just makes work more enjoyable.’ The actual challenge involves building a tall tower in a limited space. And this is precisely why prefab elements are the perfect choice. ‘It also makes it clear how important it is to be alert to things in the early stages of the process, such as the choice of materials.’ At the same time, using prefabricated elements makes things slightly more tense, because, in his view, experience really makes a difference when it comes to construction: ‘And, sure enough, this is the first time I’ve ever worked with them in 18 years.’ But he has no complaints so far. The construction time is significantly reduced because no separate materials need to be ordered and assembled – everything is delivered ready to use. On such a compact site, there are also other advantages: ‘Don’t you think that the site looks well organised? A clean working floor, no waste and no materials blowing around. That helps create exactly the sense of calm we need to be able to build the tower so rapidly.’
Construction work started on Stepstone on 1 April 2022. Completion is expected in the first quarter of 2024.
In the years ahead, we are working with VU and Amsterdam UMC to transform the Kenniskwartier (Knowledge District) in Zuidas into an exciting mixture that brings together a wide variety of different functions. In this neighbourhood (on the south side of the A10, between Parnassusweg/Buitenveldertselaan, A.J. Ernststraat and Amstelveenseweg), there will be around 2,700 homes alongside space for education and knowledge-related business, healthcare, culture, shops and hospitality. Boasting Stepstone, the new ADORE Research and Diagnostic Centre, Rialto VU cinema and The Pulse of Amsterdam, the Kenniskwartier is set to become a place where housing, interaction, inspiration and knowledge-sharing come together.