Relaxation thrives in solitude—whether in forests, mountains, or by the sea. But hidden beneath a city apartment building? That's unusual. Yet that's precisely what unfolds here: a complete private spa sanctuary underground. Every element of a world-class spa is present—from sauna and swimming pool to fitness studio and refreshment bar, complemented by a thoughtfully redesigned garden. Cologne-based Kraus Architekten brought this ambitious vision to life, executing extensive underpinning work to make it possible.

A retractable 9.5-meter glass front dissolves the boundary between interior and exterior, drawing nature seamlessly into the space. Room divisions fade away. Rich greens from planted areas blend with warm rust-toned Corten steel edges, while grey planting beds and beige terrace tiles extend this carefully composed palette indoors. The fitness area's deep forest-green walls evoke tranquil woodland—a tone that reappears on the ceiling above the 4 x 12.5-meter swimming pool, punctuated by shimmering golden light accents. Lighting is central to the spa's character: warm pool-edge fixtures create intimate moments, while column spotlights reflect off gilded bases and capitals, amplifying the luxurious ambiance. These columns carry the five residential stories above, strategically replacing original exterior and basement walls in a complex structural solution. They serve as open divisions between pool and wellness zones, architecturally defining the entire spa experience.

Visual connections between zones create a sense of boundless space. Each area's materials are purposefully chosen to reinforce its distinct character. Warm walnut wood veneer brings residential comfort to the light-tiled sauna and pool areas, while herringbone parquet flooring grounds the fitness and wellness zones. The bar counter echoes the golden shimmer from the pool hall, paired with white sofas to add a touch of glamour. All technical systems remain concealed in the deepest basement level—created during the extensive underpinning work. Here, beside the bar, a staircase descends to a rustic wine cellar, distinguished by raw brick walls and dark flooring that contrast beautifully with the elegant, luminous spaces above. Relaxation, as it turns out, takes many forms.

www.krausarchitekten.de

Photography Credits:

Andrea Dingeldein
www.andreadingeldein.de

(Published in CUBE Cologne Bonn, 04|21)