How Much Does Basement Underpinning Cost?

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Are you one of those people opting to underpin their basement but don't know how much will it cost? Well, this article is for you. We have done the research and asked construction experts how much will be underpinning your basement cost you.

The total cost of underpinning completely varies from one basement to another because of many factors to consider, but underpinning alone may cost anywhere between $350 to $450 per square linear foot, that is about two feet. An important thing to note is that underpinning is no simple project, so you have to ready a generous amount of money if you are planning one.

Considering if you should underpin your basement and whether or not it is worth it? Stick around until the end of this article so we can help you make up your mind about underpinning your basement.

Man with Level Laying Concrete Block Skirting. How Much Does Basement Underpinning Cost

What is the cost for Basement Underpinning?

Now that we know how much underpinning is, we must tell you that the given figure above is just part of the total expenses expected. Normally, lowering your basement floor can reach $20,000 or even as much as $50,000. More intricate underpinning will result in higher prices.

Your pricing can vary depending on many factors such as the manpower needed for its construction, the surface area of your basement, and the additional walls needed. All of this has to be considered when lowering your basement floor.

Underpinning is expensive because a major makeover is required to accomplish it. Special tools and equipment are used to make the job faster and smoother, which are not easily accessed by non-professionals. You should not go cheap on this because it will affect the output of your underpinning.

Underpinning is directly dabbling with the foundations of your house by lowering your basement a few feet underground. This is why it is very imperative to have the proper men to do it, and the proper equipment needed for the project.

It is advisable to go to a trusted engineer to help you plan and avoid any costly mistake that may damage the integrity of your house. Since this type of project requires a good amount of money, seek professionals to do it for a better finish so your hard-earned cash will be spent worthily. 

underpinning of a victorian property part of a sequence of images illustrating the process

Should I underpin my basement? [pros & cons]

There are many reasons why many homeowners underpin their basements. With the prices of real estate rising like bananas today, property owners lower their basements for extra storage space and extra rooms for their houses.

Some underpin their basement to convert it into renting places for extra income. Houses with underpinned basements are also valued higher in the market. So, if you are planning on selling your house, this can be a good way to sell it at a higher price.

Another reason why you may consider lowering your basement floor is that it adds integrity to your structure, it reinforces the foundation of your house adding stability and sturdiness to its structure.

And since underpinning helps your house's integrity, sometimes it is also used to salvage damaged foundations of old or not properly built houses.

Underpinning your house is like hitting two birds with one stone, it adds more room and storage at the same time adding more strength to the foundation of your house; helping it last longer, and keeping you safe in your home

The downside of underpinning is the high cost of it, because it is a hard task to do, you will need professionals to do it. It will take several weeks or maybe even more than a month depending on how big and elaborate your plan is. Details about how long underpinning will be discussed later on.

Underpinning also takes up space on your property during the renovation with machinery that construction people use, excavation can be a very messy process, and if it goes under some parts of your house's foundation, you cannot use that part of your house.

How much can you underpin?

It boils down to the preference of the owners and how high your basement ceiling is from your basement floor. There is no limit to how deep you can go, but the deeper, the more expensive and harder it is.

Most of the time, underpinning makes your basement ceiling eight feet, making the average underpinning about 2-2.5 feet. But before going any deeper, have your soil checked, let your engineer evaluate it to know the limits of the soil your house is built upon.

If you are undecided how tall should the basement ceiling from the basement floor should be, we have already answered that in one of our previous articles titled, How Tall Does A Basement Ceiling Need To Be?

This is why consulting with a structural engineer is the best way to go. They can give you a construction plan and a bold overview of what is possible for your basement, and a step-by-step guide of the procedure that will be done.

Another reason why you should consult before executing, with consulting, the engineer can tell you realistic plans for your basement. Maybe what you are envisioning is not plausible for your place, an engineer can help you make a plan closest to what you are trying to achieve.

Thinking of adding more depth to underpin for your basement but worried about the additional cost it may take? Read our article about how much does it cost to dig a basement deeper? This may help you in estimating additional costs if you choose to go down this path.

Underpinning for strengthening the foundation of an existing building

How do you underpin a basement?

The first step in underpinning your basement is to consult a structural engineer. They will evaluate with you and help come up with a very realistic plan for you to achieve what you want for your basement underpinning. Never forget to apply for building permits and inspections from your city to avoid any hassle.

The next step is taking off the concrete floor, your floor will be removed and excavated to the planned depth of your engineer. At this stage, gravel will also be removed until you are left with dirt, this is done because new gravel will be added later on with new concrete.

As you dig, pins will be placed to support your footings as you excavate deeper. Joints will be inserted to help the load with the foundation of the house to prevent it from being fragile.

After excavation, your new plumbing lines will be installed for the basement, if there will be any problem with the new plumbing, for example, it is not aligned with the original plumbing of the house, they will put a sewer injector to fix this

Once all the piping is done, it is time to pour your gravel and concrete, now you are near the finishing stages of your underpinning. When the cement is dried up, it's time to lay down your tiles or carpets, and you may now begin finishing up with your desired interior design.

The video below is a more detailed description and step-by-step procedure on how to lower your basement. Feel free to check it out to have a more visual description of what to expect during your basement underpinning.

How long does it take to underpin a basement?

The length of underpinning varies because of the different styles and constructions of basements, but the general work for underpinning can range up to 3-4 weeks and sometimes even more. It is also noted worthy that you should also take into account the length of taking the necessary permits.

Some building permits can take a long while, especially if you are doing it in the summer where a lot of building permits are being passed. Some permits to be signed might even take 30 days to be released.

If you opt for waterproofing, you can expect an additional 8-20 weeks depending on the size of the basement, you should also take into account the finishing touches like the painting and exterior design of your basement.

Do not be impatient with the time that it takes to accomplish this, if things are done in a hurry, structural integrity may be a trade-off. Such projects are expected to take some time because, unlike DIY projects, renovations like these use heavy machinery and multiple manpower, so patience is the key.

Underpinning for strengthening the foundation of an existing building. How Much Does Basement Underpinning Cost

In summary

Underpinning can be a costly upgrade for your home and if you are deciding to do it you should be ready for the expenses that might come along your way. Just remember to make the most out of it, consult professionals and plan with them. Lastly, be creative when designing it, so you can fully enjoy it when it's done.

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