A look at gambrel roofs, also known as the Dutch Colonial Roof
Gambrel Roof diagram by Zern Liew (via Shutterstock).
The gambrel roof is almost two roofs in one. Instead of the isosceles triangular structure of a gable roof, it comprises of a shallow gable at the top with a deeper gable slightly angled to the walls.
It is said that the oldest standing gambrel roof structure can be seen on the second Harvard Hall at Harvard University. This structure was built in 1677. There is a similar claim that the Alexander Standish House in Duxbury, Massachusetts is older still, being built in 1666. Lack of evidence for the latter has favoured the University of Harvard.
Mansard or Gambrel?
Historically, Europeans have assumed that a gambrel roof is exactly the same as a mansard roof. In some contexts, mansard has been used to denote the top room of any building, particularly in France.
Comparing the two roof types, the sides of a mansard roof are pitched. On the sides of a gambrel roof, they are gabled.
A Gambrel roof; notice the gables on the sides. Image by Cynthia Farmer (via Shutterstock).
A Mansard Roof: notice the difference between this roof and the gambrel roof in the other diagram. Image by Zern Liew (via Shutterstock).
Is the Dutch Colonial Roof exactly the same design?
Yes, being as this style of roof originated in the Netherlands. Dutch settlers sailed to what is now known as Manhattan Island. They christened their colony New Amsterdam, which expanded and became New York. Houses used what are alternately known as Dutch Colonial Roofs, with the name based on its Transatlantic roots.
Where would I normally see gambrel roofing?
The north-eastern part of the USA, around New York is a happy hunting ground for this type of roof. They are mainly used in housing, with the roof pitch amenable for attic space. They may also be seen on public buildings, barns, and as grandstands at sporting venues.