How Much Does a Foundation or Basement Cost?
$4,093 - $13,482
$4,093 - $13,482
Updated August 2, 2022Reviewed by Cati O'Keefe, Expert Home Building & Sustainability Contributor.
On average, foundations cost $8,518 or between $4,093 and $13,482. Foundation costs range from $5 to $37 per square foot. You might spend anywhere from $7,000 to $44,500. Slab foundations cost $12,000 on average while poured basements add $20,000 on average. The price depends on your location, the size of your home, and the foundation type.
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|Typical Range||$4,093 - $13,482|
|Low End - High End||$1,134 - $26,000|
Cost data is based on actual project costs as reported by 679 HomeAdvisor members.
|Foundation Type||Average Per Square Foot||Average Total Cost|
|Monolithic Slab||$5 – $16||$7,000 – $20,000|
|Stem Wall||$6 – $18||$8,000 – $24,000|
|Pier and Beam with Crawl Space||$7 – $14||$9,000 – $17,500|
|Crawl Space||$6 – $18||$8,000 – $24,000|
|Cement or Cinder Block||$9 – $15||$11,500 – $19,000|
|Basement||$20 – $37||$24,000 – $44,500|
Monolithic slab installation costs $7,000 to $20,000 on average. It averages $5 to $12 per square foot but can reach $16 per square foot for multi-story homes, depending on the thickness and how much reinforcement is needed. Contractors often pour the footings and slab at once, making it a fast process with lower labor costs.
Generally, contractors will use monolithic slabs to ensure thicker, sturdier reinforcement for load-bearing walls and perimeter areas rather than using footers. Builders may use monolithic slabs on level ground to ensure a more densely compacted pour.
A stem wall foundation installation costs $8,000 to $24,000 total. You’ll pay $45 to $55 per linear foot for the stem wall alone. These require more labor, excavation, and materials. Installation involves a poured concrete slab, the foundation (stem) walls, and footings (concrete pads), which extend into the ground beneath the walls.
Contractors often use stem walls on sloped lots because they can accommodate different heights to fit the terrain. Builders can increase or decrease the free-board distance between the slab and ground to deliver taller or shorter build heights. Stem walls are stabler when coupled with fill dirt, often making it a solid choice for builds on tricky terrain.
Pier and beam foundations (or post and pier) cost $9,000 to $17,500 or $7 to $14 per square foot. You’ll pay between $500 to $2,000 per pier. Pier and beam consist of piers and posts that support multiple horizontal beams. This type of system creates a crawl space to house electrical, plumbing, and HVAC with easy maintenance access.
Pier and beam foundations work well in earthquake-prone areas, as they can accommodate more ground shift than other types of foundations. Their flexibility means less damage from earthquakes and the crawl space offers easier repairs from the potentially relatively minor damage an earthquake can cause, depending on its magnitude and the home’s condition.
Foundations with a crawl space cost $6 to $18 per square foot or $8,000 to $24,000 on average. Both stem and wall and post and pier create a crawlspace. It’s not a type of foundation but rather a space created by other types of foundations. They can have finished floors with slap or simply use gravel or dirt.
Homeowners often prefer crawlspaces to install and run piping, wiring, and ducting. Some crawl spaces offer enough room to hold an HVAC unit or water heater. Contractors often prefer them because they provide easy access to the pipes, wiring, and ducting to make repairs.
If unventilated, they can harbor moisture and promote mold growth. There are several ways to combat this—like insulation and vapor barriers—to consider during planning. Measures for preventing potential moisture issues include:
Insulation costs $1–$5 per square foot
Vapor barriers cost $0.50–$0.70 per square foot
Dehumidifiers cost $1,300–$2,800
Crawl space to basement conversions costs $60,000–$150,000
Sump pump installation costs $650–$2,050
A cinder block foundation costs $9 to $15 per square foot or $11,500 to $19,000 on average. You can use cinder blocks for a variety of foundation styles, including full basements, crawlspaces, stem walls, and piers.
Cinder blocks make fine foundations when reinforced with steel rebar and filled with mortar. The combination of this reinforcement and cinder blocks’ compressive strength make them a solid choice in many environments. However, blocks are more leak prone than slabs; homes in wetter environments must take precautions to reduce the chance of water damage.
"The opportunity to bring daylighting into the basement allows you to use more of your home's space without feeling like you are underground. This is important as more people opt to work from home. A naturally lit basement is a boon for resale as well."
Cati O'Keefe, Expert Home Building & Sustainability Contributor.
Building a basement foundation costs $24,000 to $44,500 on average with finished costs adding another $25,000 to $145,000. Such a wide range reflects the finish level. While the most expensive option, finished spaces provide the greatest return on investment.
Building a basement foundation averages $15 to $130 per square foot. Unfinished basements cost $20 to $37 per square foot. The price depends on land conditions and whether you opt for a finished or unfinished space. It’s most cost-effective to finish it during initial construction.
Unfinished basement install costs $20–$37 per sq. ft.
Finished basements cost between $20–$120 per sq. ft., not including the foundation
Refinishing your basement costs an average of $6,500–$18,500
Installing a walkout basement door costs $2,500 to $10,000, pushing your project closer to $100 per square foot. But it opens your basement for a future rental unit. With rental income, you can make back your investment in 2 to 5 years. You'll need to install a few other items to meet code requirements for a rental. You can wrap these up in your basement remodeling costs or split them up as follows:
For labor alone, you’ll spend $4,500 to $18,500 or 40% to 60% of the total foundation pour price. Labor prices vary a bit by region too. You’ll spend more in high cost-of-living areas with higher wages.
Installing a basement under an existing house varies in price depending on what you’re looking to add. For example:
Crawl space with slab: Installing a slab under a crawl space costs $5,000–$15,000. There’s no need to jack the house up to put anything under it.
Full basement: Installing a full basement costs $30,000–$70,000. You’ll need to raise the house, brace it, dig underneath, set forms, and pour. Finally, you’ll have to set your house back on the foundation.
House raising: The cost to raise a house is $3,200 to $9,900.
Slab: Pouring a slab under a raised structure comes in somewhere in the middle or $10,000–$40,000.
Other foundation costs range from $500 to $39,000 for modular and mobile homes and garages. Most of the price comes from the type of installation and how thick and reinforced it needs to be.
Concrete shed foundations and garage slabs cost $2,000 to $7,000. Building a garage costs anywhere between $17,000 and $39,000, including the foundation. Attached garages cost less to build than detached ones. Concrete slabs cost $5 to $10 per square foot for the thinner slabs needed for these structures.
Mobile home foundations cost $7,000 on average but range from $3,500 to $25,000. Mobile home-specific codes may vary across cities and states, limiting foundation types. Here are some common options:
Floating slab: $6,000–$15,000
Pier and beam: $500–$1,000 per pier
Block and footing: $3,500–$15,000
Manufactured and modular home basements: $12,000–$25,000
Concrete runners: $2,000–$5,000
Even with a poured slab and basement, you’ll need to consider a few other factors that influence your budget, such as inspections, permits, soil composition, engineering, and extra excavation costs.
Foundation inspections cost $300 to $600. Expert structural engineers spot weaknesses and potential failures. They’re excellent to employ when repairing a foundation, installing one under an existing structure, or after your contractor has finished the project. As part of the permitting process, most locations require a basement to pass inspection before work can continue.
Laying a foundation requires a plan. You must adhere to local building codes and have inspections from the city or county while you build—it is important to follow local codes and get the correct permits in advance. Anticipated planning costs are likely to include:
Architect fees run around $2,000–$10,000
Building permits cost $450–$2,300 or $1 per sq. ft. on average
Soil construction reports range from $800–$5,000. You’ll want to obtain a full geotechnical report because soil composition and capacity play a big part in determining which type of foundation you need.
Factoring in radiant heat and drainage will add to your project estimate.
Radiant floor heating costs $6–$20 per sq. ft.
Drainage features cost an additional $4,100 on average
Plan these upgrades in advance—it’s far cheaper to install these during construction than later. Your pro needs to place drainage pipes and hydronic radiant heat tubes before pouring your concrete slab. You can install newer electric radiant heating later for the same price.
Sealing or waterproofing concrete costs $2,300 to $7,300. In general, concrete sealants add $0.50 per square foot for the materials.
Sealing: $3–$9 per sq.ft.
Full waterproofing: $5–$10 per sq ft.
Not all basements need sealant, but it helps to avoid future repairs. Repairing water damage costs $3,000 or more. Extreme damage can lead to complete rebuilds.
|Preventative||Cost Per Square Foot|
|Regular Performance Sealers||$0.15 – $0.25|
|High-Performance Sealers||$0.50 – $2.50|
Installing piles costs $25 to $70 per linear foot of pile with a minimum cost of $32,000. That price includes labor, equipment, and materials. Although the terms often get used interchangeably with “piers,” they serve a different purpose. Piles underpin various foundation types, bypassing poor soil to bedrock when the soil isn’t good enough to build directly upon.
Piles aren’t a standalone foundation, so add the following prices to other foundation types.
|Pile Material||Cost per linear foot|
|Wood||$15 – $23|
|Steel hollow||$23 – $46|
|Steel H Shaped||$23 – $62|
|Steel pipe filled with concrete||$29 – $52|
|Concrete||$35 – $70|
You’ll use piles for extra reinforcement in the soil. This is especially true in loose soil or where you can’t easily reach higher-bearing-capacity soil. You can also use piles to repair bowed or sagging foundations. Your pro does this by driving them next to the existing walls and tying them together.
Driven deep in the earth, piles transfer the weight of the foundation past the poor soil to solid bedrock. You can use them under a slab foundation or under pier and beam foundations. Always hire a structural engineer for pile foundations.
Installing a basement for new construction costs $18,000 to $30,000, on average. Some of the most significant expenses in the process come from:
Excavation and grading
Materials contribute to budget fluctuations.
Cinder block walls cost less than poured concrete, but aren’t as durable.
Higher quality drainage systems can raise your initial estimate, but they could save you money on future repairs.
Other material factors include insulation, sealers and waterproofing.
A full foundation replacement costs $25,000 to $115,000. If you see signs of damage or settling, such as cracks, it is important to pursue repairs right away. Foundation repairs cost an average of $4,800.
Hiring an engineer costs $525 for a home structural report. They’ll correctly assess the situation and make recommendations for repairs. Structural engineers help answer some important questions that affect your budget, including:
Can your home withstand the pressure of being raised?
What type of materials would work best in your environment?
Raising and replacing your foundation costs $25,000 to $115,000. You’ll need to budget for the following three parts of the project:
Raising your house costs $3,500–$10,500
Excavating costs $1,500–$5,600
Rebuilding runs $25,000–$120,000
This isn’t a project you should DIY unless you have experience and a working knowledge of soil types, hydrostatic pressures, and engineering. Improperly installed foundations can cause your entire home to fail. Professionals also have the right equipment to excavate your property, grade the soil, as well as pour and finish the concrete. Hire a local general contractor to oversee the project or find a foundation installation company near you.
The best type of foundation for a house depends on the climate and soil you’re building in. For example, in a marshy area, you’ll likely want deep piles set to the bedrock with the house built on top of these, while in an arid climate with a high water table, you’ll likely go with a slab on grade. Basements work great in most areas so long as the water table is low and there’s space to excavate a hole.
Insulated concrete forms cost $9 per square foot on average. It lessens the time spent on form setup, and there’s no teardown. The insulation simply stays in place. Traditional concrete foundations cost $12 per square foot on average, making ICF foundations more cost effective for homes in areas that require or benefit from sturdier insulation.
It’ll cost you $6 to $18 per square foot to pour concrete into a crawlspace, including finishing work. Many homeowners find the cost worth it, as crawl spaces provide additional storage and easy-to-access space to make repairs to essential wiring, ducting, piping, water heaters, and HVAC systems.
Foundation depth depends mostly on climate, foundation type, and the soil type you’re building on. It can range from almost surface level to dozens of feet deep. Your pro should know and follow all local and/or state building requirements. Still, it’s always best to check local requirements yourself to confirm foundation depth requirements.
Most concrete slab foundations are 4 to 6 inches thick. However, heavier homes might require thicker slabs, especially if the slab will support a garage holding several large vehicles and/or machinery. Your needs, budget, and local building codes will impact your slab’s thickness. Be sure to discuss these and other factors with your pro.