If your premises is in part use, the responsible person must ensure any fire safety systems for the protection of life are fully checked by a competent person as soon as possible when vacant areas are planned to be brought back into use, and ensure they are tested before occupation.
The routine testing and maintenance of all fire safety measures, to ensure they operate and perform as required in event of a fire, is essential in keeping people safe. This includes in any areas that may temporarily be out of use as a cost-saving measure.
You should review your premises' fire risk assessment prior to the cessation of testing and maintenance of fire safety systems to ensure this does not cause additional risks.
If any doubt exists as to the purpose of any fire safety system that may not be maintained advice should be sought from a competent person and/or your local fire and rescue service.