Argyle is mostly two-storey, mostly gabled, and there is a run of streets where every third house has the same frontage. We have lit enough of them to know what a roofline is going to measure before the tape comes out.
That matters more than it sounds. Most of what makes a quote wrong is a surprise at the site visit — a second gable nobody mentioned, a peak that turns out to need a lift. On a house type we have done forty times, there are fewer surprises.