1738 < 1776, wow, amazing to be part of history!Thanks. The roof on the part of the house you can see in that photo (which is the 1770's wing) is standing-seam metal installed before my time, so I can't be 100% certain of the material but I do believe it is steel. That's the back corner of the current house, which I believe is built upon the corner of a former house on this site, dating to 1738. Subsequent owners have been expanding it ever since.