Is it legal (or green) to have an unswitched bath exhaust fan with nightlight that runs 24/7?
Try to talk to whoever is responsible for the design of the house retrofit/refurbishment. Why houses (at least new or programmtically refurbished ones) don't come with an owner's manual is a constant bafflement - here's this extremely expensive, complex machine - figure it out yourself...?

What you may well have is a very tight (limited air exchange) refitting of the house, and the fans in question being the method used to ensure adequate air exchange for a healthy indoor environment. In a particularly good implementation of this, there may even be an air to air heat exchanger, warming (or cooling, in season) outside fresh air with the exhausted house air. That is more common in more extreme heating locales; it may not be cost-effective elsewhere (the heat exchangers themselves are not cheap.)

A fairly clear explanation of ventilating tight houses.