I live in a 1930's house. the under stairs area is blocked in with a small door for access. When the door is opened there is a strong bitter smell which i relate to old churches. I have checked that the air bricks around the house are clear and i cannot detect any damp problems under the stairs or any visible mold. I did carpet the under stairs area some 12 months ago. Have I got a potential problem, i could do with some help or guidence. Thankyou. Tooly.