There is nothing more amazing than a view from a hillside house (crashing waves, green forests, canyons…), so no one can blame you for wanting one. Still, with a great house comes great responsibility, and in this case, danger too. Just two years ago, a landslide in Utah destroyed one house and caused the evacuation of 27 others, and that is not the only example. In order to be safe, as everyone should be in their homes, before you buy a house, you have to inspect and understand it, and after you have to maintain it properly unless you want it to turn against you and become your worst enemy. If you are still up for the purchase, here are some things you should be aware of.
A typical problem with hillside homes is the accessibility. Heavily inclined driveways and walk-ups can be a real issue if you have a harder time handling stairs (due to illness, age, injury) or for anyone carrying a bag full of groceries or a suitcase. Navigating steep roads is another difficulty. If you are concerned for your strength and stability, you should give real thought to whether you can handle a long-term residence in such a terrain.
A landslide happens when a mass of earth, debris or rocks move down a slope because of a natural erosion or in combination with earthquakes, storms, floods, heavy rains, volcanic eruptions or proximity of a construction site. There is no particular rule where a landslide can happen; they occur all over the world. And although they most commonly happen due to natural causes, sometimes people can cause them by altering the terrain by building properties or agricultural irrigation. Of course, the only safe way to prevent your home from being hit by a landslide is to build it on a safe, previously inspected terrain and far from a slope. You can’t do that if you are purchasing an already built house. All you can do in this case is to minimize the likelihood of landslides.
Geotechnical consulting agencies advise homeowners to carefully manage the water used in irrigation and plumbing, as well as the one that naturally occurs on their lot. It is important to frequently test the water and sewer lines for any potential leaks and to direct the storm water runoffs from downspouts and hard areas (such as concrete driveways) away from exposed sloping areas. Minimize the irrigation since it is the most common man-caused cause of landslides.
The best way to stabilize the hill and restrain dirt is to build retaining walls. Although an average retaining wall is capable of stabilizing a manageable slope with small soil movements, it is not enough to hold back a pressure of a massive landslide. You can give your property additional protection by planting ground cover on slopes. This way, you will furthermore stabilize the soil. Be cautious, though, not all plants are equally efficient in soil stabilization. It is best to consult a landscape architect/designer to make the right choice.
When going house viewing, take a professional with you, and make sure the geotechnical consultant/civil engineer gets all the necessary information, house drawing and soil analysis before you decide for the purchase. Also geotechnical engineers can help you with determining the best place for building a retaining wall or some other soil stabilizer such as concrete anchors and grout curtains.
With hillside houses, you can never be too cautious, and it is up to you as a home buyer to investigate the piece of property you are purchasing, and later, as a home owner, to take care of it and maintain it the best way possible.