Basement Cost

Typical costs:

• 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.
• 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. Many experts (like Bob Vila[1] ) 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. However, house-moving companies like Klier Structural Movers[2] in Ohio assert that adding a basement to an existing house is a cost-effective addition.
• A basement alone does not guarantee safety during a tornado. 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. 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.

• Constructing an unfinished basement typically includes excavation, footings, walls, a concrete slab floor, utilities, waterproofing, drain tile, back fill and cleanup. 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. Overall, a basement adds about 3-4 weeks to the new-house construction schedule. A video[3] illustrates the excavation process.
• 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.
• 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 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 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.
• 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. A video[4] illustrates the process using a skid loader.

• For new home construction, work with the architect to include a basement in the house design and blueprints.
• For a remodeling project that includes adding a basement (either under the existing home or as part of an addition being built), the National Association of the Remodeling Industry offers tips for choosing a contractor[5] .
• If possible, get several estimates. Request and check references from previous customers. Verify that the company is properly insured, bonded and licensed. Request a written contract or agreement that specifies the work to be done and the rates to be charged.

1.  www.bobvila.com/posts/11076-cost-effective-to-add-basement?page=1
2.  www.klierstructuralmovers.com/basementaddsunderhouse.html
3.  www.youtube.com/watch?v=Xcs2LK8oEhs
4.  www.youtube.com/watch?v=wRkKqHRH43I
5.  www.nari.org/pdf/selectremodpro.pdf

Check Out All Costs for Home and Garden		How Much Does Replacing a Water Heater Cost?		How Much Do Replacement Windows Cost?		How Much Does a Storm Shelter Cost?

Today's Featured Cost Articles

Make sure your gutters are clean before they start to fill up again this fall. Are you planning a Labor Day picnic? Need a new charcoal grill? Pruning trees before the storm season can help ensure dead branches won't imperil your home. Looking for help to take care of your garden? How much does garden service cost. The late August sun can leave a mark. Check out sunburn treatment options.

About CostHelper

CostHelper is based in Silicon Valley and provides consumers with unbiased price information about thousands of goods and services. Our writers are experienced journalists who adhere to our strict editorial ethics policy.

CostHelper Community

UTI urgent care visit Paid: 147.00 Visit was $135. Antibiotics was $12. Waiting for four hours in the waiting room and the visit was quick... [more] -nervouschomper Urinary Tract Infection Treatment Cost Spanish Medical Interpreter Paid: 150.00 I worked with SynShyne Services out of Monroe, NC. They were so worth the price! Professional, friendly, accurate, great attitude and always on time. I recieved an itemized report after every contact and a user friendly invoice weekly... [more] -Gregory Richardson Interpreter Cost Dat Paid: 495.00 This is how much I am paying... [more] -Calista Christian Dental Admission Test Cost Shingrix Paid: 48.00 ... [more] -Not that BB Shingles Vaccine Cost Skin prick allergy test Paid: 573.00 Took my 9 yr. old in after an allergic reaction to eggs. Several panels for nuts, fish & top 8 allergens. Sure enough, egg came up. Got a script for epinephrine and left... [more] -D’s mom Allergy Testing Cost Estimate for Teeth Cleaning Cat Paid: 0.00 13 year old cat …teeth extractions, X-rays, blood work, anesthetic, cleaning estimate 2 to 3 thousand... [more] -Terrimarie Cat Teeth Cleaning Cost