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  • Ernest Young

I want a second story addition! Now what?

So, you've finally decided! A second story addition is the best way forward to meet your needs.

But now what? How do you know if your home can even support it? Is it allowed, will the city or neighbours block it? Who do you get to design it? Engineering did someone say? You don't know any engineers? So many questions...


Let me help you by giving you some answers to these question and more by consulting with some industry professionals in their associated fields.


First off, before you waste a bunch of time dreaming about that spa-like ensuite, you need to know if it's even feasible to add a second story addition to your home. I reached out to James Lind of Bravura Engineering here in Calgary to ask him to help shed some light on some of the question you might have, here's what he had to say...


"The first step for 2nd level additions is to determine if an existing foundation structure can support an additional level / storey. The City typically requires this to be done at the DP stage. For this Bravura needs to determine the following during an onsite investigation:

1.            Strip footing size / strength

2.            Existing foundation wall strength

For item number one it is necessary that a small portion of the slab along the concrete wall be removed in order that we can determine if a strip footing is evident and what size it is. This will typically be done in a furnace room or some other unobtrusive area (usually just hammered out)."


Another way to do this is by digging down to the footing on the outside of the house. Not always an option and not fun at all... Here's a pic of one I dug recently, not only do you have to reach the footing but you have to dig to the under side of it so the thickness can be measured. This pic was taken 2 hrs after being dug out and you can see water starting to settle already. Tomas from Bravura was very accommodating and arrived onsite to do his tests quickly and I was able to dig and close it in all within the same day.


"We will then use a Schmidt hammer test to determine the surface MPA strength of the existing concrete foundation wall at multiple locations. Provided that the foundation comes back with reported strengths of 20MPA or higher Bravura will then provide a letter under seal confirming the existing foundations capability of supporting the new construction.

If the test shows strength of less than 20mPa then we will have three core samples taken from the wall and sent out for testing as per the required CSA standards for concrete testing.

The wood frame portion of the existing structure will eventually need to be reviewed as well, however this cannot be done until the final plans are ready and demo begins. Typically the wall studs can support the loads but in many instances the existing window and door headers will need to be reinforced or replaced. If any new load is to be applied to the existing interior load bearing supports (i.e. footing pads, teleposts, beams) they will all need to be analyzed and in most cases reinforced or replaced. In most of these additions the designers try to avoid loading the interior members and instead clear span to the outside walls.

Once working drawings are ready, Bravura can provide all the engineering designs for the new structural elements as well as any reinforcement designs required for the existing structural elements."


Thanks James, that's really good information!

So, great, now we know your house can support it, what's next?


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