I've noticed inaccuracies in stair tracking like others... I work in a high-security building, Fitbits allowed but not cell phones. Our stairwells are cement, safest place in the building, but probably not the best air circulation. Each flight is about 12 feet and I don't pause mid-flight. Is it possible the construction is affecting the altimeter readings? Thanks.
PS - Love my One, 3 years and counting!