How to address moisture in house

Hi neighbors,

We ought a home with a lot of deferred maintenance and are slowly chipping away at making improvements as best we can given time constraints, competition for contractors and the high cost of materials these days. A big concern is that there is strong evidence of moisture in our outer walls: obvious mildewy smell, cracks in paint and drywall, and, around some windowsills, visible mold. The moisture appears to have entered through the periphery of our flat roof, through older window framing, and through stucco that surely needs repainting. To top it off, we are due to replace our roof and deck and are hoping to add an addition at ground level as soon as we can swing it .

I find it all a bit overwhelming and don’t know how to attack this problem and when, sequentially, given our other projects. I’m really afraid we are going to open a costly Pandora’s box and find that outer walls need replacing, etc. Who does this sort of assessment/remediation? Can they just aim an industrial-grade fan down into the walls and dry them out before we repair moisture entry points?  Would really welcome hearing from anyone who has dealt with this. I’m not looking to be further alarmed...I’m aware of the health concerns and am doing what I can to mitigate the mold I can access around windows using bleach, being careful about window coverings etc. and we run an air purifier. (A dehumidifier is not an option due to certain other health issues.) My focus here is practical: how and in what order to handle the overall structural challenges and with whom.

Thanks everyone!