Considering a basement lowering project for your home?  Lowering your basement is not your everyday home improvement project, though with the real estate prices in Toronto and the scarcity of land, it is a great option for expanding your living space without losing precious yard space.  If you want to find out more about basement lowering, read on.

Homeowners here in Toronto often ask about lowering their basement.  It’s easy to see why many select this option for their home.  In a process sometimes called underpinning, the basement floor is actually dug out a couple feet down.  This makes the basement more accessible and usable and can add to the value of a home.  Not only does it change a basement into better-added space, it also adds structural integrity to the home.

Underpinning job in Toronto home

Basement Lowering Project in Toronto Home

Preparing for the Basement Lowering Quote

As with any home improvement type project, there a few things that every homeowner should know and understand before they begin the basement lowering process.  When it comes to your basement, of course, you are looking for a foundation or underpinning contractor who is a professional and experienced with the type of work you desire.  You’ll want to find a company that has been in business for awhile, is specifically insured for this type of underpinning work and one that can provide you with plenty of references since this type of project can be disastrous if done wrong.  When it comes to the structural integrity of your home, it’s always worth checking out a underpinning contractor thoroughly before hiring.

You may find companies who are willing to bid your job on the spot without drawings, without further knowledge or testing.  That ballpark bid could end up increasing drastically after you hire as there are many variable to consider and it means they have not gone through the process properly in order to give an accurate quote, they assume they can just get the job and overbill you later after the project has started and is harder for you to back out.

A reputable underpinning company will need to see exactly what you expect them to do.  Part of the process could include demolition and drilling test holes before beginning as well as working with an engineer.  Often, when this part of the process is not done, the homeowner’s preference change and the company ends up with discrepancies in their work order that need to be resolved.

Hiring an Architect or Engineer

Part of the process for lowering your basement should include getting quotes from at least two professionals for drawings and determining which architect or engineer you plan to use before you even have a contractor come out.  Doing this part of the process ahead of time shows the contractor that you are serious about the process and will educate you on how the entire process works.  When a contractor knows you really do plan to have the work done, they don’t mind the 3 to 5 hours that are involved in coming up with a pricing estimate.  If you skip this step and ask a contractor for a bid on a basement lowering project without doing your due diligence you may end up with a range of pricing that is arbitrary and on down the road it may have no connection with the work performed.

An experienced underpinning contractor will only work with reputable architects and engineers with experience in basement lowering and can recommend one if needed.  Here at Nusite, we work with several very reputable engineering firms and architects that specialize in basement lowering.

Drawing/Plan Approval

The basement lowering drawings you received from your architect or engineer typically need to be certified and then sent for approval for a building permit., at least here in Toronto.  The inspector may recommend changes that will need to be marked on your approved drawings.  This is not an easy task so you want to make sure you have an experienced craftsman leading this project.

Understanding the Basement Lowering Quote

To understand your underpinning contractor and his pricing and process, it’s important to note that basement lowering is a very time-consuming, labor-intensive process. And a challenging project from an engineering standpoint.  Your contractor will need to follow those drawings accurately and that takes skill and experience.  Compare quotes between a couple different contractors and check to make sure the scope of work is the same on both of them.

There have been several well documented disasters in Toronto involving unqualified contractors and houses falling down due to improper shoring during the basement lowering process.  If you hire an unqualified and under-insured contractor, you the homeowner will bear most of the responsibility and legal consequences if workers or civilians get injured due to negligent work.

Scheduling the Work

When you decide upon a plan and agree on a price with your underpinning contractor, the work can be scheduled.  A contractor may be able to schedule quickly and be out in a few days or in may take weeks.  As always when dealing with a contractor, being busy is a good thing.  You don’t want to hire a contractor who isn’t busy.  It’s a bit like going to a restaurant where no one else eats and expecting a wonderful meal.

Here in Toronto, the Spring and Summer are usually the busy times for basement lowering contractors but since the work is indoors, this work can be done during the winter and you may have a better time finding an available underpinning contractor for your project.  Winter may also be a great time to head south to warmer climates while the work is being done on your home.

The Work Process

The unerpinning contractor will begin by measuring and marking everything out prior to beginning.  They dig out the basement slab and typically lower the floor 1-3 feet.  They will also shore up the underpinning or sidewall area to ensure structural stability.  We then carry out our lowering process, either bench footing (creating a bench to support the dirt underneath the foundation wall) or we underpin (directly removing the soil underneath the foundation wall and replacing it with concrete).

Once that is accomplished they typically waterproof the interior of the basement foundation, put down gravel then pour a new floor.  They also place a waterproofing membrane connected to a sump pump on the interior to help keep your basement dry.  The amount of time it takes and the cost of the project can very base on the size of your basement.  Some projects take a few days (mostly repairs) and some can extend into many weeks (average full job is 3-6 weeks).  While it is difficult to provide a price without drawings and discussions with the homeowner, you can expect this type of specialty work to run between $20,000-$50,000.

Toronto Finished Basement After Underpinning

Toronto Finished Basement After Underpinning

Project Completion

When the basement lowering project is completed, you should walk the job with the foreman or project manager.  You’ll want to check for anything that seems unfinished or anything that doesn’t look right. You want to check that the city and the engineer passed all inspections throughout the project.  Also check to make sure that your contractor and his crew cleaned up after they finished.  You shouldn’t see debris left behind unless your contractor has let you know ahead of time that you are responsible for cleaning it up.  In most cases, the contractor does the clean up and removal unless otherwise agreed upon.

Do I Really Want to Do This?

Basement underpinning is by no means, a small undertaking as you probably understand by now.  There is research, time and money involved and may seem a little complex.  Yes, it takes preparation, thoroughness and quite a bit of your hard earned money.  If you find the right contractor, your project will go much smoother.  They are the expert, let them do their job.  Having underpinning done will also gives you more usable space that you can enjoy for years to come and adds value to your home.  In today’s real estate marketing, adding that value (which does not increase your property tax) can go a long way to helping the home sell.  Making the right decisions and following the process it takes to do the job correctly will be beneficial in the long run.

Nusite Contractors are basement lowering experts in Toronto and have successfully completed hundreds of underpinning projects in Toronto and the GTA and can provide references upon request.  If you live in the Greater Toronto Area and have questions about lowering your basement, feel free to contact us here, we’re happy to answer any questions and explain how the whole basement lowering project works.  We can also recommend experienced architects and engineers if you are interested in getting started.

Toronto home underpinningIf you live in a metro area like we do here in Toronto, land is at a premium.  When an expanding family is looking to increase the living space in their home, they usually either choose going up (adding another floor), or going below (increasing the height of their existing basement).

When it comes to underpinning a basement, also called basement lowering, the advantage is that you already (somewhat) have existing walls to create your new addition.  It’s often less expensive than adding an addition to your home, and since your building within the existing structure, there is far less red tape to deal with.

The problem with older homes is that the basement was never meant to be a living space.  It was intended for storage, utilities, laundry, and a nice dark and damp home for spiders to creep about.  The height of the basement is often lower than the rest of the floors, coupled with the fact that duct work and utility pipes are usually run along the ceiling area.

Creating a full height basement is not an easy job.  To lower your basement, you’ll need to underpin the foundation so that your house doesn’t fall over like this one did in Toronto.  You’ll need a permit, a structural engineer, and an experienced structural contractor who has experience with underpinning a basement.

When you decide to create a full height basement for your home, there are two methods that can be used.  Underpinning and Bench Footing, both of them are acceptable ways to create a full height basement, and both of them have their pros and cons.  Creating a full height basement is a complex and expensive job, so you should understand the differences when you go over your options with your contractor.

Build a Stepped Bench-Footing

Bench Footing costs less than underpinning as it doesn’t require you to dig underneath the existing footings.  In this method, the existing footings and soil remain untouched.  What happens is that a new foundation is poured on the inside the existing one, all the way down to the depth of the new basement floor.  This creates a second wall inside your basement, leading to a decrease in basement square footage and a ledge equivalent to the added height of the basement.

That’s why they call it Bench Footing, you now have a bench running along the perimeter of your basement.  Some people will make creative use of the space, creating cupboards on top of the bench, while others will simply build a wall above the Bench Footing.

The width of the Bench Footing depends on the increase in height you want for your basement.  For every foot of height you add to your basement, you will need to add about a foot of width to your Bench Footing.  So if you add 18″ of height to your basement, you will have a Bench Footing 18″ in width.  These considerations need to be taken into account, especially if you will need several feet of space added to your new basement.

Foundation Underpinning

Underpinning is more expensive than Bench Footing, but allows you to retain all of your basement square footage since there is no need to build a bench wall inside your basement.  It’s a difficult job, and one not left to fly by night contractors.

Underpinning involves excavating and pouring new footings to the depth where your new basement floor will be.  This is done in sections, and the load of the foundation is carefully transferred and supported as each section is completed.  It’s a slow and careful process as you’re basically undermining the integrity of the foundation during the basement lowering process.

There are several other advantages to this model. First and foremost the basement footprint remains the same but you get the extra headroom. Moreover if you had the slightest doubt about the state of the original foundations that concern’s gone forever. This is the preferred engineering solution, though budget and other considerations may not call for it.

To Summarize the Situation

Bench-Footing is Quicker

Underpinning is Stronger

Bench-Footing is Less Expensive

Underpinning Costs More Money

Bench-Footing Bypasses Foundations

Underpinning Strengthens Foundations

Bench-Footing is the Thief of Space

Underpinning Maximises Space


The differences between underpinning and bench-footing are pretty obvious. The Underpinning may be the ideal solution whereas the Bench Footing may be the only affordable one. Look before you leap into this pond of water. If you have questions about creating a full height basement for your home (if your in Toronto and the surrounding GTA), fell free to contact us for a free inspection and estimate.

Underpinning job in Toronto homeIn theory, houses are built on solid foundations that are strong enough to bear their full weight and more. Unfortunately this is not always the case. Foundations may subside and even disintegrate for structural reasons. They can also be affected by flooding, shifting earth and heaving clay.

When this happens there are two solutions. Either you have to reinforce the faulty foundations by adding bulk beneath them, or you have to demolish the house and start again. The former, which builders call underpinning (or basement lowering), is obviously the preferred alternative. While the practice of Underpinning is used to repair a faulty foundation, it’s sometimes  done for other reasons.

Increasing Basement Height

Some basements are little more than crawl-space cellars, having been built for the sole purpose of raising the ground floor level of the house. This could be to achieve a view, level the main structure across a slope, or create a defense against flooding.

Excavating a cellar without first adding support can be a recipe for disaster. You could remove foundation lateral support and cause it to start sliding into the excavation with inevitable results. The only way to avoid this happening is to create more bulk beneath the existing foundation as you dig down. For practical reasons this is done in sections.

Other Reasons to Underpin Foundations

Warning signs are cracks appearing in walls, especially in relatively weak places like corners. You might also notice:

  • A slight tilt to the house


  • Floors moving out of level


  • Cracks in wall and floor tiles


  • Windows and doors that are hard to close


  • Gaps around doors and windows


  • An opening between the roofline and the upper walls

The first step involves digging trenches to establish whether the root cause is foundation failure, or inadequate structures built on top of it It’s also essential to determine what compromised the structure in the first place.

The Underpinning Process

The purpose of an underpinning job determines the extent of its scope. If you are excavating out a basement to increase head height, then the entire foundation needs to be progressively underpinned in sequence. However if you’re repairing a cracked, eroded or subsided foundation you may only need to reinforce the relevant part.

In either instance it’s important to dig down to at least the point where moisture levels are consistent, and to install jacks until the new concrete has dried fully. You can check ground moisture with a meter obtainable from a garden store, as you don’t require a high degree of accuracy.  Bear in mind that this involves the work of a structural engineer and construction experts experienced with basement underpinning.

Repairs to Brickwork

After you have repaired a damaged foundation you would remove and repoint loosened mortar between the bricks above. This is not only for cosmetic reasons. You will also be adding a modicum of strength to the wall itself.

The Value of a Specialist

This is not an easy job (as you can see). The work is dirty, arduous and time-consuming. The time and costs involved are also something to consider.  If you’ll be in your home for the long haul, and would like full living use of your basement, it may be worth looking into adding another level of living space to your home.

Have questions about Underpinning?  You can contact us here, we’ll be happy to answer and and all questions you may have.

This is a guest post by Bricks and Pieces, a UK based Independent design and building solution expert

Many older homes have a basement or cellar but the likelihood is that this isn’t being used for anything other than storage, if it’s being used at all. Yet in cities, where space to expand is at a premium, converting your cellar can give you useful extra space and add value to your property with relatively little disruption. The advantage of a cellar conversion over converting your loft is that it’s usually nearer to other living areas of the house. This makes it ideal for things like games rooms, gyms, studies or home cinemas.

Converting a cellar or basement into habitable space is a relatively rare task people take on in the UK due to moist air and land. It doesn’t have to be a scarce home improvement though. In most cases a conversion won’t need planning permission as you’re not changing the external appearance of the property. The exceptions are if you’re creating a completely separate living unit, a basement flat say or you’re excavating a new basement from scratch. Building regulations of course will always apply with regards to things like escape routes, ventilation, damp proofing, electrics and so on.

Is My House Suitable?

If you have an existing cellar then the answer is almost certainly yes. You’ll probably need to carry out some remedial work like water proofing and fitting a better staircase but otherwise it should be a relatively painless process.

The modern trend is to add new basements to properties that don’t already have them. Most older properties have a suspended timber floor which means that disruption to the house is minimized because most of the work can be carried out from the outside. However, some older homes have relatively shallow foundations so you may need to underpin the walls before work can commence. It’s important to get a professional to advise you here.

The biggest problem with any below ground conversion is likely to be water and how to keep it out. Rainwater may seep from the outside boundaries of the property or from blocked gutters and drains down towards the basement. Because it doesn’t get direct sunlight it can be difficult to get damp to dry up, leading to mildew and other problems. The most common solution to dealing with rainwater problems is to lay drainage pipes around the base of the outside walls so that the water is carried away before it seeps down.

Groundwater seeping into the cellar may also present a problem. In these cases the best solution is to install a lining membrane behind a secondary wall; this allows water to collect in a sump from where it can be pumped away to the outside. This is more effective than the older technique of tanking with a cement lining and works even in locations where the water table is high. Before undertaking any kind of conversion you should check if your area is liable to flooding.

Other Things to Think About

If your house is terraced or semi-detached then you’ll need to consider the neighbours. They’re entitled to inquire about the possibility of subsidence and request a report at your expense. A good architect or surveyor should be able to advise you here but it’s still worth having a chat to your neighbours before you start work.

Your cellar conversion will also need services like electricity, plumbing and heating so it’s important to work out how you’re going to provide these. Depending on the use you intend to put it to you may also need phone and TV points. To ensure safety it’s a good idea to have a smoke detector and a carbon monoxide alarm too.

If there’s a wooden floor above you’ll need to pay attention to soundproofing so that you’re not disturbed by people moving about upstairs. Don’t make it too soundproof though, you still need to hear the phone and the doorbell!

Because there’s likely to be little natural light you’ll need to pay particular attention to lighting in your cellar. The use of halogen spot lights can produce a bright, white light and they can be embedded discreetly in ceilings or walls. The décor can help here too, opting for lighter colours can help to give the whole thing an airier feel.

There are lots of uses to which you can put a converted cellar, you’ll find plenty of inspiration online if you’re stuck for ideas. Whatever you want to use it for a cellar conversion can enhance your lifestyle by allowing you to utilize an under-appreciated resource in your home. It can also add significantly to the value of your property.

If you’re thinking of going underground with a cellar conversion, Manchester as an area offers you the chance to choose a specialist who can advise you on the best way to proceed.