The phrase "as their offices" is correct and usable in written English.
It can be used when referring to the locations or spaces where individuals or groups conduct their work or business activities.
Example: "The company has expanded its operations to several new cities, establishing branches as their offices."
Alternatives: "in their workplaces" or "at their locations".
It also claimed the researchers used the Friends of the Earth headquarters in London as their offices.
Doctors are allowed to work at home, too, as long as their offices are on the ground floor.
"You just need to look at the amount of bearded young folk with laptops and tablets to see that they're all using coffee shops as their offices".
As their offices were destroyed in an arson attack for accusing the military dictator of squandering millions, the editor faced arrest or exile.
The law enforcement officials, Attorney General John J. Farmer Jr. and the state police superintendent, Carson J. Dunbar, were appointed in 1999 as their offices were being scrutinized because of racial profiling.
The Indian army and paramilitary forces beat several journalists, refused to respect their curfew passes and even forced closure of leading newspapers as their offices remained locked and the journalists were denied access.
"They use it as their office".
Lawyers Ken Perry and William Aronin sit in the poky downtown Manhattan apartment that serves as their office.
He thinks that the relationships between people and objects such as their office buildings, schools and other things can be represented in the same way.
They had a cargo container as their office and marked their presence with flapping flags and big signs with their belligerent symbol, a raised assault rifle.
Music-streaming service Soundcloud and the mapping business Here (owned by BMW, Mercedes and Audi), for example, use English as their office language in Berlin.
