A video illustrates the process using a skid loader. Adding a basement to an existing house requires: building permits and engineering plans raising and supporting the house excavating the basement space (and hauling away the dirt) re-grading and creating new drainage and pouring concrete footers, floors and walls.In warmer climates where the foundation does not have to be as deep (typically 18"-20" for a crawlspace or a few inches for a slab foundation), including a basement adds more to the total cost of the house because it requires a lot more additional excavation, far beyond what would be done without a basement. In those areas, adding a basement during new house construction may require only a few more feet of digging to create a usable basement area. In colder parts of the country, a home's foundation must be below the frost line, which can require digging down several feet (typically about 2.5'-5', depending on location).In some areas a basement is not feasible because of a high water table or unusual soil conditions (particularly in coastal or marshy areas, or in many parts of Texas, Oklahoma and Arkansas) the cost of excavating through solid rock or because there is frequent earthquake activity.A video illustrates the excavation process. Overall, a basement adds about 3-4 weeks to the new-house construction schedule.
A finished basement typically includes all of that plus flooring, walls, ceilings, drywall, windows, and additional waterproofing and more in order to provide the desired living space.
Related articles: Basement Remodeling, Basement Waterproofing, Flooded Basement, Repairing and Sealing a Basement, Storm Shelter, Home Addition Having a prefabricated safe room (a welded steel box, a steel skeleton with steel planks or a prefabricated unit that is bolted together on site) installed in a basement can cost $3,000-$20,000 or more, depending on materials and size. Building a structurally-reinforced safe room area inside a basement (whichit can double as a closet, bathroom or utility room) can add $6,660-$14,300 or more to the total cost, depending on size (the number of people expected to take shelter within it), materials used and location within the basement. A basement alone does not guarantee safety during a tornado.However, house-moving companies like Klier Structural Movers in Ohio assert that adding a basement to an existing house is a cost-effective addition. Many experts (like Bob Vila ) estimate that it is less expensive and less risky to build an above-grade addition or an addition with a basement, next to the existing structure. Adding a basement to an existing house can cost $30,000-$70,000 or more, depending on the size of the existing crawlspace or half-basement or if the house is on a slab foundation, and how much of the work is do-it-yourself and how much is done by contractors.Including a basement as part of new house construction can increase the cost of the house by $10-$25 or more a square foot for an unfinished basement, or about $10,000-$50,000 or more for an average house and $30-$100 or more a square foot for a finished basement, or about $35,000-$175,000 or more for an average house with costs depending on location, soil conditions, the size and shape of the basement area (unique shapes with more than four corners cost more), the materials/finishes used and additional features like a bathroom or laundry hook-ups.
Although traditionally residents of tornado-prone areas have been told to take shelter in a basement if a storm shelter is not available, a basement does not necessarily function as a good tornado shelter unless the basement has been designed and reinforced for that purpose. Unfinished Basement, New Construction: $10-$25+ a Square Footįinished Basement, New Construction: $30-$100+ a Square FootĪdding Basement to Existing House: $30,000-$70,000+Ī basement can add additional storage, workshop or living space to a house, especially where it isn't possible to expand out or up. 2022 Cost of a Basement - Estimates and Prices Paid - CostHelperĬostHelper > Home and Garden > Construction & Renovation > Basement