Learn about the costs and considerations associated with raising your home and relocating a home out of a major flood zone.
Raising a home is a personal solution for protecting a house from flooding, but before deciding to raise a home, there are several factors to consider to ensure that this is a viable option.
Relocating a home out of a high risk flood zone is another flood mitigation option in which a homeowner moves their home to a less vulnerable area on the same property or on a new property.
Elevating your home
Raising a home is a personal solution for protecting a house from flooding. Before deciding to raise a home, there are several factors to consider to ensure that this is a viable option. Factors to consider include: elevation height, elevation technique, the home’s foundation, home accessibility, and additional hazards besides flooding.
The height that a home is raised depends on the base flood elevation (BFE) of the area. The BFE is the elevation that flood water is expected to reach during the “base flood.” The BFE is also a regulatory requirement for the elevation of a home that determines the flood insurance premium. The base flood elevation of a property can be found through the county’s FEMA flood insurance rating map (FIRM). Homeowners are also encouraged to add 1 or 2 feet of elevation to the local base flood elevation in order to provide protection from higher flood events. Flood Factor shows the future projections of flooding of a property and the future depths of flooding could be used to determine the extra elevation needed.
The image above depicts a home being raised by placing the home on piers.
Home in the process of being elevated on posts.
Raise the foundation
The elevation technique to raise a home depends on the home’s foundation. Ideally, as much of the original foundation as possible can be maintained in order to save on costs. For all elevation techniques, a design professional must evaluate if a home’s foundation can handle the lifting process and building loads. Piers, posts, columns and pilings are considered open foundations. Slab-on-grade, basement, and crawl space foundations are enclosed foundations that can be elevated onto the previously mentioned open foundations. Homes with these enclosed foundations can also be raised by extending the foundation walls, by extending the walls of the house, or by abandoning the first floor area and building a new second-story living area. For all of these options, the necessary permits must be obtained, the foundation must be evaluated to see if it will support the elevated house, and utility services and lines must be disconnected.
Home that has been elevated by extending the home’s foundation.
Extend the home
To extend, or heighten, a house’s foundation walls, the house is lifted from the foundation and the existing foundation is added to until the intended elevation is reached. Openings are created in the extended foundation so that floodwaters can enter and exit. To heighten the walls of a house, the roof and roof framing must be removed so that the walls can be extended. The walls are then added to, the windows are raised, and a new elevated floor is constructed above the flood level. The area below the raised floor has openings in it so that flood water can enter and exit. To abandon the first floor area and build a new second-story living area, the roof and roof framing must be removed, a second story is built, and openings are created in the abandoned first floor.
Extending the foundation walls, extending the walls of the house, or abandoning the first floor area and building a new second-story living area all raise the living area of a home out of flood levels and create openings in the previously closed foundations so that flood waters can enter.
Open foundation options call for excavation around the old foundation, cutting holes into the foundation so that the network of lifting beams can be installed, and typically removing the old foundation so that the piers, pilings, or columns can be installed.
The image above depicts a home being elevated by extending the foundation walls.
Each of these options requires a large financial investment and the cost of each option varies depending on the existing condition of your home, how much you have to elevate your home, and what option is best for your home depending on the flooding your area experiences. Often, rebuilding happens when FEMA grants money after a disaster like Hurricane Harvey. These grants can often cover the majority of the cost for rebuilding. The median price of elevating a home is $130,000. Please note, an important first step is to contact the local zoning and building departments prior to making any improvements.
Elevating your home also means that your entry doors are now at a higher level and so you will have to create a new way to access your front door whether that be by stairs, ramps, or elevator. Additional modifications may need to be made to your home to ensure it can withstand the elevation process and can also withstand other hazards such as high winds or earthquakes if your neighborhood is prone to these hazards. The site of your home may not have ideal soil conditions and perhaps relocation could be a better option for some.
Home that has been elevated with columns.
Relocating a home
Relocating a home out of a high risk flood zone is a flood mitigation option in which a homeowner moves their home to a less vulnerable area on the same property or on a new property. A home is lifted off its foundation, placed on a flatbed trailer, brought to the new location, and then lowered onto a new foundation. It is important to note that although this method is effective in protecting a home from flood risk, it is typically the most expensive retrofitting method. The entire property a home exists on may be in a flood zone so moving a home may require the purchase of a new property out of the flood zone. To see property, neighborhood, city, county, or state flood risk go to Risk Factor. Local government pages also can show local flood maps or connect to FEMA flood maps so that people can have a full picture of their potential flood risk.
The image above shows a home that has been lifted from its foundation and is being moved. Source.
What to consider when relocating
There are many considerations to take into account before relocating a home. The condition of a home dictates whether it will be moved successfully or not. A home moving contractor must inspect the condition of a home before it is lifted to make sure it is structurally sound. The size, design, and shape of a home also affects how easy it will be to relocate a home. Homes of greater size and weight, such as masonry homes, are harder to move than lighter wood frame homes. Single story homes with crawlspace or basement foundations allow contractors to easily lift homes from the foundation because it is easier to install lifting equipment on these foundations. Make sure to acquire the necessary permits before moving a home on public roads. Also, it is important to make sure that a home can physically fit on the route to the new relocation site. Consider narrow roads, low clearances under bridges, and restrictive load capacities of roads.