Topping up without rules? Challenge accepted: the Nassaubad.
05‑02‑2026

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Last Friday’s coalition agreement got us thinking as an architecture firm. Topping up without rules? No permits, no objection procedures, no aesthetic committee, no architectural policies? It sounds like a fast track to more housing. But does it actually work like that in practice?

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We investigated it. And here it is: GIDS – the Amsterdam Nassaubad.
A thought experiment by IMPAKT exploring whether fewer rules truly accelerate rooftop additions in a dense urban environment like Amsterdam.

Our starting point: adding floors to the Liander (transformer) substation on the Nassaukade. A 1960s block in a stunning location along the Singelgracht, set for renewal between 2030 and 2035 anyway. What if we build upward here?

Below are our findings:

Case

We saw potential for a rooftop extension that gives something back to the neighbourhood: live‑work studios, an active plinth, an open‑air theatre by the water, and even a swimming pool with a slide.
We build higher, completing the large building blocks along the Marnixstraat. Its scale matches the Europarking building and the police station, and the neighbouring rooftop park could continue upwards.
Roll in the construction cranes!

But once you dive into the practical realities, the picture shifts.

Lessons Learned

• Liander is a utility company, not a developer. There is no shared interest yet in taking on such a risky development. And why would you combine a transformer station with other functions at all? (Risk!)

• How do you bring such different interests together?

• Developers see opportunities, but also the complexity:
  Building on or next to critical infrastructure demands political will and strong risk management.

• Amsterdam’s land prices make the business case fragile.

• Technically, it’s feasible: a concrete table structure topped with lightweight timber construction works excellently (thanks JAJO).
  But precisely because rooftop additions add value, it’s frictional that demolishing and rebuilding the ground station may be simpler. Without aesthetic review or policy, the easiest path quickly becomes the chosen one.

• And then there are the neighbours: shadow, views, privacy. All legitimate concerns.

• We leave the issue of electromagnetic fields aside, but it is certainly a sensitive one.

Fewer rules, more speed?

If only it were that simple.

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In Amsterdam’s real-world rooftop development practice, removing permits or aesthetic requirements is not the true accelerator. The bottlenecks lie deeper:

• Realistic land prices

• Thinking beyond housing alone

• Architectural policy: how do we create coherence in rooftop additions?

• Shared interests between landowners and developers

• Transforming monofunctional sites into multifunctional ones

• Compensation for adjacent or underlying owners

• Allowing height accents

• New selection and procurement processes that encourage market‑driven initiatives

• More homes = more parking pressure? Should we top up the Marnixstraat parking garage as well?

Without these systemic adjustments, removing rules or aesthetic review mainly produces paper acceleration.

A call to the sector and to government

As a sector, we must show what truly happens in practice, so policy can align with reality.

See housing, amenities, mobility, green space and energy as one integrated whole. Only by thinking bigger can we solve multiple problems at once.

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