Before antibiotics the only known treatment for tuberculosis was clean air, sun and rest, which made the sanatorium a building type designed like a medical instrument. Alvar and Aino Aalto, who won the 1929 competition, distributed the functions into separate wings: patient rooms to the south, communal balconies at the angle catching the longest sun, services to the north. Up to this point the scheme is the modernist logic of its day.

Where it departs is where the scale shrinks. Aalto said he designed for 'the person lying down': ceilings were painted a soft colour that would not tire a patient looking at them all day; lighting was placed out of the direct line of sight; windows were built in two layers so that cold air would not blow onto the bed; heating came from above. The basin was shaped at an angle to reduce the sound of water striking it — so as not to wake the patient in the next bed. The Paimio chair he designed the same year sets the back angle to ease breathing.

The approach is an internal correction to modernism's assumption of a standard dwelling for a standard person. Aalto was inside CIAM, but he treated function not as an abstract scheme but as a particular body's need at a particular moment, which is also why he kept using timber and brick alongside concrete and steel. After tuberculosis became treatable by drugs the sanatorium became a general hospital; it has been protected since 2005 and entered UNESCO's tentative World Heritage list in 2021.