Question

Figure shown below represents ________

(a) Barrel roof

(b) Dutch gable, gablet

(c) Saw-tooth roof

(d) Butterfly roof

The question was posed to me in an online interview.

My enquiry is from Roof Covering, Sloping Roof & Flat Terraced Roof topic in chapter Rules and Methods of Measurement of Civil Engineering Drawing

Answer 1

Right choice is (d) Butterfly roof

Easiest explanation: A butterfly roof (sometimes called a V roof or London roof) is a form of roof characterized by an inversion of a standard roof form, with two roof surfaces sloping down from opposing edges to a valley near the middle of the roof. It is so called because its shape resembles a butterfly’s wings. Butterfly roofs are commonly associated with mid-century modern architecture. The form has no gutter as rainwater can run off the roof in no more than two locations, at either end of the valley, often into a scupper or downspout. The form may be symmetrical, with the valley located in the center, or asymmetrical with an off-center valley.