Does a patch appearing after work prove the cause?
Report the timing and what changed, but leave the explanation open for appropriate assessment. Coinciding events do not establish one source by themselves.
Should I include details of window work?
Reliable dates and tasks can be useful context, along with wetness observations. Do not assume they confirm the current cause or suitable treatment.
What if I cannot obtain old work records?
Share what you know and identify uncertainty. Photographs, approximate timing and current observations can still help describe the enquiry.
Does treatment include altering ventilation equipment?
Installation and related tasks need separate clarification. Ask what is recommended, who will carry it out and what is included in the quote.
Should I open a newly decorated wall to check?
Do not disturb construction for the enquiry. Explain what is visible and discuss appropriate assessment or authorised further access.
Will another general clean resolve the new concern?
Ordinary cleaning has a different scope. Request mould and moisture assessment directly instead of treating it as normal household dirt.