Garage-to-house concrete step in an Ottawa home: Code rules?

A step between an attached garage and the house sits inside the building, so the outdoor rules on this site (the City's landscaping advisory, the exterior stair width and the exterior handrail exemption) are not the ones to rely on. We found no City statement on whether building such a step needs a permit, so ask the City's Building Code Services before work begins.

The Code rules that apply come from several sections of O. Reg. 163/24. On dimensions, Table 9.8.4.1 sets the rise at a minimum of 125 mm and a maximum of 200 mm, and the run at a minimum of 255 mm and a maximum of 355 mm. The tread depth must be at least equal to the run and no more than 25 mm deeper than the run (section 9.8.4.2(2)). Risers must be uniform: the maximum difference between adjacent risers is 5 mm, and between the tallest and shortest riser in the flight it is 10 mm (section 9.8.4.4). Treads and landings slope no more than 1 in 50 and must be wear-resistant, slip-resistant, and smooth, even and free from open defects (section 9.8.9.6).

Width, handrails and guards for a step inside the garage are questions to put to the City's Building Code Services and your contractor; we did not research the interior rules for them. A guard is required where the difference in elevation is more than 600 mm within 1.2 m of the walking surface (section 9.8.8.1).

On the concrete itself, section 9.3.1.6(1) sets at least 32 MPa for garage floors and exterior flatwork, with a water-to-cement ratio no higher than 0.45 (section 9.3.1.7(1)); ask the contractor to specify the mix in writing. If the air temperature is below 5 °C when the concrete is placed, section 9.3.1.9 requires it to be kept between 10 °C and 25 °C during mixing and placing, and maintained at not less than 10 °C for 72 hours after placing.

Section 9.35.2.2 also requires an attached garage floor to slope to drain liquids to the outdoors, so the step and the floor need to work together.

Before hiring, ask the City's Building Code Services whether a permit is required for this specific step, and ask the contractor to put the concrete mix strength, footing depth, riser and tread dimensions, and any cold-weather protection plan in writing in the quote.

When you review quotes, ask each contractor to break out the cost of removing the existing step separately from forming, pouring and finishing the new one, so that line does not disappear into a single number.