How can spaces of production and living coexist meaningfully? Can they enrich each other, spatially, socially, and ecologically?

Huis Zeep is an architectural project situated at the harbor’s edge in Rotterdam, combining living, production, and wellness within a circular system. The core idea: transforming greywater—lightly contaminated wastewater from showers, sinks, and laundry—into soap.

The greywater comes from two sources: docking ships and the building’s own apartments, which are located above the production facilities. After mechanical and chemical filtering, fats and oils are extracted and turned into soap. The remaining clean water is reused—for instance, in the laundromat beneath the production floor.

Soap production becomes the architectural spine: it starts in a 45-meter-high tower and flows into an adjacent industrial hall, where stepped basins turn the process into a spatial experience. Movement, material transformation, and public visibility become interwoven.
Excess heat from the production process is reused in a wellness area, which includes pools, saunas, and relaxation zones. Visitors pass through the production hall via a wide stairway alongside the soap basins, experiencing the cycle from raw greywater to finished product.
Above, hotel-like apartments are arranged in flowing, zoned layouts. A wide, south-facing access balcony connects the units, offering views over the harbor and the production spaces below. At the top, a bar and restaurant crown the structure.

Huis Zeep explores architecture as a system in which waste becomes value—and the resident becomes both user and contributor in a visible, sustainable loop.