Rijksdienst voor het Cultureel Erfgoed, CC BY-SA 4.0 <;, via Wikimedia Commons

Jean Housen, CC BY-SA 4.0 <;, via Wikimedia Commons

Rijksdienst voor het Cultureel Erfgoed, CC BY-SA 4.0 <;, via Wikimedia Commons

Zonnestraal Tuberculosis Sanatorium designed by Johannes Duiker and Bernard Bijvoet Hilversum, The Netherlands, 1925-31. The sanatorium’s construction was commissioned by the Dutch Diamond Workers’ Union for its workers who, breathing the air contaminated by dust particles in the polishing and profiling workshops of the stones, frequently suffered from respiratory conditions that used to lead to the development of tuberculosis.

Translated as ‘sunbeam’, Zonnestraal was centered on providing sunlight, fresh air, and cleanliness for patients’ recuperation. Each patient had their own bedroom with an adjoining sun balcony. Arranged in a loose "pin-wheel" formation, the building complex created adequate space between patients' rooms to ensure unobstructed sunlight fell on the balconies throughout the day. Predominantly made of transparent materials, the design of the buildings was intended to allow as much light as possible to enter the patients' rooms. With such dramatic transparency the building ran the risk of overheating. To counter any effects of overheating the architects incorporated a cooling system into the building, an innovative addition for the period.

Focused upon the engineering required to enable as much light as possible to enter the building, the design of the sanatorium can be referred to as Heliotherapeutic Architecture, an architecture focused on the healing property of sunlight. Heliotherapeutic Architecture was a relatively short lived style due to the discovery of effective medications for the treatment of TB in 1944 (streptomycin and para-aminosalicylic acid) and the revelation of “triple therapy” (streptomycin, para-aminosalicylic acid and isoniazid) in 1952, leading to a cure for the disease.

In 1928 the Finnish architect and designer Alvar Aalto visited Zonnestraal, influencing his work on Paimio Sanatorium.