MTF, as far as the two pitches on a Mansard are concerned, the French terms for those are brisis for the lower steeply-pitched roof section, and terrason for the slacker-pitched upper roof section. FWIW, I think the shape of Mansard you built was handsomely proportioned. The shape of the roof can vary quite a lot, as you noted, and I also don't like the ones where the lower pitch dominates, or those designs where the upper pitch is at all steep. I like to layout the Mansard roof using the half-circle method.
Chris,
Can you explain the "half circle" method or lead me to the post in the earlier thread on this topic. I poked around there but could not find "half circle" described.
One method that gives good proportion for a "mansard" is what I call "inverted layout." ...with the lower slope at two-to-one (rise-to-run) and the upper slope is its inverse: one-to-two.
