What slope is too steep to build on?
Considering this, how hard is it to build on a slope?
Steep slopes are difficult to access with the heavy equipment needed to build your foundation. The time required to build your foundation is often increased, and it may be necessary to pump concrete to your foundation. This can mean increased costs. Sloped home sites also present drainage challenges.
Keeping this in view, is building on a slope more expensive?
Your costs will be more than a home on a flat lot. The excavation can be six times more expensive depending on many factors such as grade, rock, and access. The foundation will require much more concrete and cost up to three times more.
But if the home is built on a slope of tress and vegetation then the home must have good drainage systems in place that prevents water from (1) getting into the home and (2) eroding the soil and making the hill unstable. Bad drainage equals an increased risk of land / mudslides and damage to the home.