It depends on whether you are talking about the cost of a skillion roof when building a home or the costs of the inherent problems that ensue with low pitched skillion roofs.
What is that you say? Inherent problems – low pitched skillion roofs are probably the worst because of condensation problems.
There is nothing new about a skillion roof being very prevalent of the 1950’s and 1960’s. Although it may be recognized in today’s terms of modern to have a skillion roof, I can see probably in the ensuing years a lot of remedial work for roofers trying to alleviate the problems of condensation within the low pitched skillion roofs. Maybe they may look nice and modern, however long after the builder’s obligation to you is over this is usually when the condensation problems start.
As a roofer with over 50 years experience in the roofing industry I can honestly tell you that flat roofs and low pitched skillion roofs have always kept me busy from June through August doing remedial work due to massive condensation problems.
Condensation problems do happen in conventionally pitched hip and gable roofs, however this is generally due to bad workmanship.
If I myself were going to build a house knowing what I know about condensation
In low pitched roofs I would be definitely making sure there was a decent roofspace. Skillion roofs should have to have a really decent roofspace. If you are thinking of a design with a skillion roof make sure that the ceiling is not on the underside of the rafters and make sure you have a really big roofspace, otherwise go conventional hips or gable.
All roofspaces need effective roof ventilation to alleviate the condensation problem of winter and the inherent heat problems of summer.
Universal Tile Ventilators have the best roof ventilation systems in the world.
The Universal Tile Ventilators for tiles roofs and the Smoothline Ventilator for corrugated colorbond roofs.