Lake County Health Department is a two-story (with basement), reinforced concrete structure with a rectangular footprint. The building, designed by William A. Ganster and William L. Pereira and completed from 1938-39, was oriented with southern exposures for all of the patient rooms, which accomodated 90 beds. The building's original exterior was defined by steel frame windows with frosted glass transoms and transparent fixed and ventilated panels. The installation was conceived to modulate light and natural air for patient comfort. Each room was also provided with its own terrace, and allowed patient beds to be rolled outdoors. The complex's north wing includes the original main entrance, administrative offices, and the original out-patients' clinic. The exteriors of all three sanatorium buildings are characterized by flat roofs, absence of ornamentation, and a strong horizontal composition reinforced by ribbon-like windows and railings of the patients' quarters. The linear arrangement of the buildings was optimized for southern exposure and views of the site's spacious wooded and grassy slope.