Erco Technical Centre, Lüdenscheid

Designed by architect Uwe Kiessler, lighting manufacturer Erco's Technical Centre was completed in 1988. It was chosen by Graham Haworth of Haworth Tompkins. It was a particular challenge to photograph on the day of our visit, as the weather was poor, although this did little to temper Haworth's enthusiasm.

"Every time you walk into Erco Technical Centre, it feels uplifting – with an openness and a great quality of light, even on an overcast day like today," explains Haworth in 50 Architects 50 Buildings. "It feels like a clean slate. I just wish I'd designed this building."