Lets just start with what we consider an average underpinning project and it’s size. In Toronto older home basements are typically around 800 sq ft and owners want to extend foundation wall by 2.5 feet.

From day 1 construction and no extra work we expect to finish it within 5 weeks. It is not really weather dependent, but city inspectors are sometimes late to respond, which drags timelines.

We assume to finish underpinning and excavating all sections within first 3 weeks, assume 1 week for all inspections or reports and have the last week for waterproofing, installation of drains and finishing concrete.

Additional work such as initial demolition, basement walkouts and outside drain work would extend our timelines.

All problems come from assumptions or not thinking through the future use of basement after it is underpinned. It is not the job of an architect or engineer to guide you through all possible outcomes – They just draw structural details.

Here is a list of common problems:

• Sizes of existing exterior walls and footings are guessed
• Main sewer drain is higher than proposed basement slab
• Future renovation floor plan
• Exact size and position of beams and posts
• Waterbed level

Completing drawings and work under one company automatically eliminates most of these issues.

We always talk about completion time or cost for average project, but each project has to be priced separately.  Site specific drawing provided by an architect and details calculated by structural engineer.

First of all we are looking at accessibility. Driveway and ability to put a bin with soil belt is a basic requirement for underpinning project to be considered average. Otherwise most of excavation and carry out soil has to be done by hand, which drastically increases the cost.

Secondly Rock Basements needs to consider the size of project. Typically the larger it is, the cheaper it comes down to per square footage of space or per linear foot of foundation wall.

And the last detail we look at is the complexity of work and all the specs. It includes depth of excavation, thickness of new foundation and footings, additional specs for type of concrete pour method and reinforcement.

Committee of adjustments is used to overcome construction limits established by local regulations or bylaws.

If your project includes increase of home footprint, overall roof pitch height, total square footage above ground, set backs or addition of new legal units – you may need to go through committee if the plan is to go above suggested limit.

Basement underpinning in Toronto does not follow under those limitations and does not require committee of adjustments. For that reason, entire home remodeling project may be separated into two different permits. That allows you to finish basement underpinning while proposal is under review for rest of the project.

Eventually you will get a permit for underpinning basement. It can take longer or may need several revisions if city is not quite sure what you are planning to do in certain situations within and outside of the house.

Normally when there is a deficiency or lack of information from an architect or structural engineer on proposed drawings, city department would request clarification or additional information.

City typically reviews and responds for basement underpinning permit within 3-4 weeks. The main question in how long does it take to prepare adequate and detailed drawing?

Architect starts from visiting jobsite and completing all necessary measurements for calculations and actual drawings. After that he/she prepares set of drawings with details and specs. Further it is sent to structural engineer for confirmation and stamp.

All of these steps take up to 2-4 weeks in best case scenario. Additional time may be needed if revision is required by building department before permit is released.

So far we have explained average basement underpinning costs without additional work. However most clients and general contractors do not stop there. Very often we are asked to complete other aspects of concrete and structural work.

Here is a list of additional costs in our line of work:

• Basement Walkout – $15 000 to $25 000 each
• Window Cutout – $500 to $1000 each
• Exterior Drain/water Replacement – $4 000 to $6 000 each
• Initial Demolition and disposal – $1 to $3 per square foot
• Block/Concrete Addition – $60 to $100 per square foot
• Concrete Slab – $10 to 15 per square foot
• Frame and Pour Footings – $25 to $50 per linear foot
• Excavation – calculated on site

Home owners want to make their new basement height somewhere between 8 and 9 feet height after remodeling finish. That includes flooring, ceiling drywall and even heated flooring system. In rare cases we have happened to see underpinning jobs with finished basement height of up to 10 feet.

Existing crawl space or old house basements are typically from 5.5 to 6 feet in height. That makes the difference of about 2-3 feet. We need to consider excavating at least 8-12 inches deeper than that for installation of footings, drain pipes and new concrete slab.

There are many rebates available in Toronto for home owners that are upgrading their property and underpinning is one of the areas where you can get part of spent money back.

Most of it is for waterproofing and damp proofing services completed while lowering basement, but there is a possibility to get HST rebates while renovating and upgrading majority of your home. Sometimes our clients get up to 10% money back. See available rebates!

Every job is different, but 99% of the time, basement underpinning is only first stage of planned work. It is followed by basement finish work or entire house renovation project.

While planning our stages we need to communicate to everyone else who will continue on after us and make sure they are happy with everything.

These can be exact window cutout for installers, specific blocking or structural support for carpenters that will frame rest of the house, drain and water lines for plumber and even our plan of work outside for arborists.