The Latin root meant "work-doing," and for centuries the word referred to a duty, not a room.
The word office entered English around 1250 from the Old French ofice, meaning a duty or a religious service. The Old French derived from the Latin officium, itself a contraction of opificium, which meant "work-doing," combining opus (work) and facere (to make or do).1
For its first three centuries in English, office had nothing to do with a physical space. It meant a position of authority, a ceremonial function, or a religious observance. A person held an office. The word described responsibility, not real estate.2
The spatial meaning appeared gradually. In 1560, Cosimo I de' Medici commissioned a building in Florence to house the administrative and legal functions of the Tuscan government. The Italians called it the Uffizi, their word for offices.3 English usage followed a similar path. By the seventeenth century, "office" could refer to the room where official duties were carried out.
The compound "office hours" appeared in English by 1841. "Office furniture" was attested by 1839. "Office party" did not arrive until 1950.4
The transition from duty to room accelerated during the nineteenth century, when industrial-era corporations needed centralized locations for clerical staff. The open office and the org chart emerged to manage these growing concentrations of administrative workers.
In American English, "office" expanded further. A doctor's office, a dentist's office, a lawyer's office. British English retained more specific terms, preferring "surgery" for a doctor's practice. The American usage reflects the word's long drift from sacred duty to commercial space, from opificium to cubicle.5