A key benefit of building on a hill is maximizing the surrounding views from your lot. But building a house on a hill is more challenging and expensive than building on a flat lot. Here are some factors to consider before you embark on such a project.
Check your local building authority and planning department for rules and regulations on developing your site. If you are building on a sloped site, it is likely that there are maximum height and retaining wall restrictions on your lot. If you are building on the top of the hill, visibility of the property may trigger a review by the planning department, as a house will have an impact on the environment.
Check whether there are utilities located close to your lot. City utility services were not always built in accessible areas. Make sure there is level access or a road to a hilltop lot, because locations that are difficult to access will drive up the cost of construction.
Obtain a soils report from a geotechnical engineer. A soils report will examine the type and stability of the soils on your lot, and the report will contain recommendations on the best type of foundation for the location.
Your house will be more exposed to the elements, so design it to include an outdoor area sheltered from prevailing winds. If there are no mature trees on the hill, incorporate roof overhangs to help reduce solar gain.
Engage a structural engineer to design your foundation and structural system. Besides standard seismic and structural loads, a engineer will also have to account for higher wind loads on a hill.
Be sure your budget accounts for the extra expense of building on a sloping lot. The foundation system is typically more expensive than for a flat lot, requiring driven piles or concrete caissons. The extra time to construct a more complicated foundation will mean increased labor and material costs.
Always check with your building authority and planning department for requirements in your area.