The process may also change if you are making more drastic changes, which could involve changing the height of the roof. Changing the pitch size would involve additional structural changes such as replacing the roof’s ridges, eaves, props, rafters, and even external walls. The estimations below are based on the average 3 bedroom semi-detatched house in the UK which has a gable roof with a pitch of 25 degrees. This article is, of course, no substitute for professional advice — which should always be sought when considering replacing a roof. If you're interested take a look at how construction statistics and how it may affect material costs. They use the same shingles, but these two installation methods are very different. If you have any issues relating to wherever and how to use shor.by, you can make contact with us at the site.