"adjacent rooms" is correct and usable in written English.
You can use it to describe two rooms that are near each other. For example, "The hotel suite had two adjacent rooms, each with two queen beds."
They write in adjacent rooms, most days.
Julien's two films are shown in adjacent rooms.
In five large adjacent rooms underground, he is reproducing some of his greatest hits.
Syms builds on this sense of voyeurism in the adjacent rooms.
Clara and I began to disappear into adjacent rooms with strangers.
All three roommates got along "great" and will live in adjacent rooms this year, she said.
Inside the gallery, visitors will find a varied display of wall works in two adjacent rooms.
In a hotel room a couple of male shooters – one of photos, the other of guns – book into adjacent rooms.
In adjacent rooms with beds were four younger Asian women wearing matching silky lingerie, each a different bright color.
She had put her husband & her lover in adjacent rooms while she slept in her father's house.
In small, adjacent rooms, discussions on the Chilcot report, between readers and the audience, are due to take place.
