When ever I move I have problems with what I would call hay fever, just simply some dust or pollen my body is not use to. Biggest was on return from the Falklands and Living in Suffolk, there was so little dust or pollen in Falklands and so much in Suffolk. Putting ones finger on exactly what it is can be hard, mould spores can be hard to identify as often we are unaware the mould is growing.
Last house there was a corner cut from a tile, not a clue why, but the extension with this faulty tile took 20 years before the leak became apparent, and another 5 before we found the cause, having fibre glass wet for so long was likely to encourage mould growth, and was likely one reason for hay fever, but only I had a problem, as only I did not live in same house for years, I worked away and had a problem each time I returned home.