According to the art. 5 of the OECD model convention (see link) "the term "permanent establishment" means a fixed place of business through which the business of an enterprise is wholly or partly carried on. [...] and it includes especially:
a) a place of management;
b) a branch;
c) an office;
d) a factory;
e) a workshop, and
f) a mine

Alternatively, you can also use "operating premises"

An operating premise is a ‘fixed commercial establishment through which the company’s activities are wholly or partly carried out’
Operating premises can be subsidiary branches, commercial offices, manufacturing sites, workshops, sales points, permanent representations and mines (Art. 5 para. 2 of the OECD model).