Schulungsgebaude HWK, Koln

Schulungsgebäude HWK – Cologne, Germany
Project overview

The training centre for the Chamber of Crafts (Handwerkskammer) in Cologne is a showcase for integrated building services. The facility includes classrooms, workshops and administrative offices, all of which benefit from natural light. The project team pursued an ambitious energy target, aiming to minimise solar heat gain without resorting to tinted glass that would darken the interior.

Design challenge

The building features large window areas to provide daylight for training workshops, which are often located deep in the building. Traditional solar‑control glass can achieve low solar heat‑gain coefficients but tends to reduce visible light transmission, making rooms feel darker. The goal here was to achieve an SHGC of around 0.07 while maintaining a high visible transmittance and ensuring occupants could view outside.
retrosolar.us
.

RetroSolar strategy

The centre employs a triple‑layer glazed façade with integrated RETROLux 50 mm blinds and RETROLuxTherm 12 mm micro‑louvers
retrosolar.us
. The blinds and louvers are miniaturised to maximise visibility, achieving approximately 65 % visual transmission even when the blinds are horizontal
retrosolar.us
. The system relies on low‑iron glass and double low‑emissivity coatings to enhance thermal performance. The vertical support profiles are spaced at 38 cm, allowing spans up to 53 cm for the glazing units. This precision assembly ensures that the blinds operate smoothly and that the cavity remains airtight.

Building physics and performance

The combination of RetroSolar blinds and micro‑louvers achieves an SHGC of 0.07 without the need for tinted or absorbent glass, which means the building still receives ample daylight. The micro‑louvers, barely visible from inside, reflect high‑angle sun, while the larger 50 mm blinds handle lower sun angles. The integrated system reduces secondary heat radiation and improves insulation due to the air gaps between the panes. As a result, the building maintains comfortable temperatures with minimal energy input for cooling or heating.

Architectural outcome and significance

The Schulungsgebäude HWK demonstrates how a sophisticated combination of micro and macro RetroSolar components can achieve remarkable thermal and visual performance. The transparency of the façade enables passers‑by to see the activities inside, celebrating the crafts taught within. Internally, the daylight quality supports learning and concentration. The project serves as a teaching case for other institutions considering advanced glazing systems.