2016/07/22

What Is The Cost of Underpinning and Lowering My Basement?

Basement lowering and underpinning

Many homeowners these days are weighing the pros and cons of lowering their basement to create extra living space for a growing family.  We are often asked the question: What is the cost of underpinning my basement?

With the cost of real estate on the rise and with less inventory to meet demand, more homeowners are choosing to “love it” rather than “list it” when it comes to making the decision on whether or not to sell.

If you are looking for more livable space in your home, the basement is the first place you should look.

But what if your basement is unfinished or needs to be lowered to provide a comfortable space? In many older homes, the basement was never meant to be a living space with low ceilings and exposed ductwork reducing the amount of headroom.

Basement lowering is definitely no easy feat considering the time and resources required. However, it goes a long way to expand your living space.

Benefits of Basement Lowering

Also known as underpinning, basement lowering entails digging out the basement floor several feet down. This will add value to your home by ensuring the basement can easily be accessed and used.

In addition, underpinning also enhances the integrity of the structure thus uplifting the face of your home.

Basement lowering and underpinning

Underpins are installed in sections to support the structure while lowering the basement floor

Generally, these basements are about 6 ft high, and lowering the basement by 2 ft for a total of 8 ft for headroom is the desired height.

Here are some terms you will want to familiarize yourself with before you meet with a contractor.

Benching

Our estimators like to explain to the homeowners how benching differs from underpinning.

The benching system is used to create extra living space and is often less costly than underpinning and may take half the time, but will also reduce the livable space once the job is done.

The first step is to have engineer drawings and permits. Once we are more familiar with the structure of the home, we can start to remove the concrete floor and dig down to the new floor level.

If you lower your basement 1 ft down then this means your concrete bench needs to be 1 ½ ft out from the interior wall.

This is a good option if you have the space to sacrifice. For instance, if you are in a semi-detached home where a shared wall is involved, you may have to use the benching system as underpinning may not be an option.

What Is the cost of underpinning and basement lowering Google Docs

Concrete bench needs to be 1 ½ ft out from the interior wall.

Underpinning:

Most homeowners choose to go this route because it gives them the option to use their basement as a rental property which in return will give them a source of income, and/or allow for a fully finished basement.

Like Benching, the first step is to pay for an engineer to provide drawings and permits. The concrete floor is removed and the soil is excavated to a proper elevation.

bencings

The pins that will support the footing are dug out in sections according to the engineer’s drawings, typically in three stages to ensure that the wall is supported at all times as the footings are dug out.

If new posts are required for existing beams or columns, then new footings for posts are installed, which means temporary jacks are installed to support the beam and hold up the house as the new footings are installed.

Once all three stages are completed, the new plumbing is installed.  If the elevations for new plumbing cannot be met then a sewer injector will be required.

We then install the interior drainage system (the weeping tile) as per the engineer’s drawings or building code requirements. A minimum of 3 inches of ¾ gravel is placed on the floor as a base. Then a new concrete floor is installed and trowel finished.

If you want to learn more about Basement Underpinning, download our most recent case study

So, How Much Is This Going To Cost?

In order to provide a quote, the following must be taken into consideration:

First things first, you will need to conduct some of your own research in order to find the most suitable plan for your home. How will the extra living space affect the quality of your life or value of your home?

You will also need to seek the services of a structural engineer. Generally, the cost of the project will be determined by your plan and the contractor/engineer you hire. Usually, we give the homeowner a ballpark so they can decide on whether or not they should get an engineer to provide the drawings. The cost of the engineer’s drawings are usually around $2,000.

The ballpark is based on square footage, depth, and access. Basement lowering is certainly not your everyday project and there may be special considerations that affect the cost. Normally, the base cost of underpinning is priced per linear foot. For example, the cost to excavate two feet in depth is anywhere between $350 and $450 per linear foot.

Basement lowering goes a long way in giving your home a complete makeover. However, it is a huge job that will affect the overall structure of your home and you have to do it right.

Don’t take any chances or cut corners and make sure the company you choose to do the work has underpinning insurance and liability insurance. Check references and make sure the company you choose specializes in this type of work.


RCC Waterproofing and Foundation Repairs has been servicing Ontario customers for 96 years. Their repairs have outlived lifetime warranties by at least two times. The company provides professionally trained sales representatives to view, assess and quote on repairs. The installers are employees of RCC and most have long term working relationships. RCC carries full insurance including WSIB coverage and HST registration.

RCC Waterproofing offers:
  • A Lifetime Waterproofing Guarantee!
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  • 96 years of third-generation family success both in products and services and superb warranty
  • Full-service options, providing either exterior or interior repairs depending on issues, location, and structure
  • A successful record of servicing over 75,000 customers

To learn more, contact RCC Waterproofing at 416-747-1920 or Toll-Free 1-888-766-2071 or Contact RCC for a Free Inspection