You can estimate the cost of your concrete foundation based on a cost-per-square-foot of concrete the contractor will lay. This usually ranges from $4 to $7 per square foot. Although many different factors will impact the overall cost of laying a concrete foundation for a new home or building, the square footage of the space is one of the biggest. Below is a breakdown of the national average cost for a concrete foundation based on square footage:
3,000 - 15,000 square feet: $15,046
2,500 - 3,000 square feet: $12,240
2,000 - 2,500 square feet: $10,022
1,500 - 2,000 square feet: $6,487
1,000 -1,500 square feet: $5,747
500 - 1,000 square feet: $5,318
Under 500 square feet: $2,417
What is included in the overall cost of concrete foundation?
The total cost of laying a concrete foundation will include more than just labor costs and material costs. When you hire a contractor to lay a concrete foundation, any one of the following services and add-ons might be included in your total. All of them vary individually, and can impact the overall cost of your project: Soil testing or drainage
A concrete pour typically starts with a soil test to determine the best mix of concrete for the job and how much excavation you will need. How well a site drains and how rainwater moves on the site are also key considerations.
Whether you need assistance obtaining building permits
Most licensed contractors help clients navigate the process of applying for necessary building permits. The plans and drawings needed to get the permit must be in compliance with the local building codes. Some contractors will acquire permits for their clients, with an added fee to cover their time in addition to the permit fees.
Whether or not you'll need excavation
Building on a sharp grade is more complex than a flat surface. The builder will have to secure the foundation with deeper footings or other methods, all of which cost more.
Similarly, if you need to level the area on which the foundation is to be laid, the total cost will increase by about $2,000. It will also extend the project timeline by a couple of days.
The depth of your foundation
The depth of the foundation is another key pricing factor. Foundations are described as:
Deep: those that need to be more than three feet into the earth
Shallow: as in standard slab-on-grade foundations, which consist of a single layer of concrete poured on a flat surface over a layer of gravel for drainage.
In general, the deeper the foundation, the more it will cost to lay, since you will need more concrete and it will take longer. For example, you will pay more to pour the foundation for a crawlspace than you would for a full-height basement. Footings are relatively shallow columns of concrete dug into the ground at the edges of a foundation to support architectural features such as stairs. Each individual footing costs around $150 and, if you need them, can add to the overall price.
Adding a full basement or walls
Pouring a foundation for a structure that will have a basement is more complicated and expensive than a standard foundation, since concrete walls will be added to define separate rooms.
A full basement can add $13,000 to $30,000 or more to the total cost of building a new structure, depending on the width and height of the walls and whether the space includes utility hookups, windows and other features.
Whether you're building a basement, adding vertical elements (like a foundation wall) to a project increases its complexity. Expect this to add an additional cost as well.
Whether you want to finish the foundation
One of the last steps of a typical concrete job is finishing, or honing the pour. This is done by vibrating the wet mix to remove any bubbles in the pour. Then, using a buffing machine while the concrete is still damp, the contractor will smooth out any irregularities to create a finished surface.