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Standard Step Height and Depth (Complete Guide)

When you are up to the task of building your dream house, you perhaps can’t imagine how many unknown rules and regulations you must follow.

If you are not aware about them, your contractor may take the advantage of your ignorance, or you may be handed over some tickets for building code violations.

The step in your house is one such thing that must be constructed following the standard guidelines and procedures. To save yourself from future inconvenience, you must know about the standard height and depth of the step.

Standard step height and depth

The standard measurement of the height of the step is 7.5 inches following the American codes. For the depth, the average number is 10 inches. the maximum step riser can go up to 7.75 and can’t be less than four inches. The width depends on the owner’s preference but must be at least 36 inches.

You may wonder since this is your house, you should have the final say about your steps and how you like them.

But, considering many accidents and injuries along the way, the building codes have decided to specify the ideal range of height, width, and depth to prevent any unforeseen falling off the stairs accidents.

Also, with the ideal number given, the total calculation of the height of your stairs becomes easier. Let’s find out the standard height and depth of the step.

Height:

If you reside in the United States, the individual step height for your home must be from 7 to 7 ¾ inches.

Considering the standard height from the base to the first floor is nine feet, you have to decide the individual step height. If you are from Canada, the maximum height riser will be 8 ½ inches.

The stair riser, which is a vertical, wooden piece locating at the backside determines the height from one step to another. The variation between the risers on the stair is 3/8 inch usually but may rise a little bit.

But when it comes to the nose of the tread, the maximum acceptable height is 1 ½ inches above the riser. 

The minimum height requirement for the step is 4 inches. It can’t be less than that. If you own a dog with a small leg size, the height can drift a little from 7 inches, but never lower than four.

However, if you are planning for open riser stairs, the maximum height should be four inches, considering your child’s safety.

Depth:

The depth is probably the most crucial part of the stairs considering that is the surface you step on. This is the distance from the nosing or front edge of one step to another, measured in a horizontal line.

The average depth of the step should be 10 inches at the minimum. If the stairs are solid risers instead of open risers and do not have nosing, the minimum number rises to 11 inches.

Tread measurement should be identical or almost identical. The largest tread depth of the flight of stairs should be less than 3/8 inch larger compared to the smallest tread depth. The more identical, the better.

Because, with an asymmetrical tread depth the descending will be an issue, if not the ascending. In case of solid risers, the nosing should be 3/4 inch minimum.

Is an 8 inch step too high?

Depending on the local code of your residential area, it will vary. In the United States, the number is indeed high but not inconspicuous.

In many countries including Canada, the 8-inch height of the step is quite common. The IRC denotes the maximum height to be 7 ¾ inches.

In a standard 9 feet walled building, there should be around 15 to 17 steps, considering each step to be 7 ¾ or less than that.

8 is not very bigger in number than 7 ¾ inches but may put a grave impact, especially if the residents are senior citizens, children, or have a bad knee. It might be difficult for the pets too.

So, 8-inch is too high for the step and without the mortar, it will be a serious violation of building codes. Considering the convenience and safety of the people, keep the height of each stair below 8-inches.

What is the building code for step height and depth?

The International Residential Code, in short IRC, handles the standard requirements applicable in residential buildings.

According to the IRC, the maximum stair riser can’t be more than 7 ¾ inches and less than 4 inches. Moreover, the difference between the height and depth should not exceed 3/8 inch.

For the depth, the IRC requires the number to be 10 inches or more for nosing attachment.

The nosing must be a minimum of ¾ inches from the front edge and a maximum of 1 ½. Without nosing, the minimum number should be 11 inches. The code doesn’t specify any maximum number for depth.

International Building Code or IBC deals with the commercial sides of the buildings. There are some variations in dimension when it comes to IBC compared to the IRC.

Even though the minimum number for the stair risers is the same both in residential and commercial, that is 4 inches, there is a dissimilarity in the maximum height.

According to the IBC, the maximum height for stair risers can’t exceed 7 inches. Also, both with and without nosing, the depth requirement is 11 inches under IBC. But the acceptable variation of height and depth is similar.

4 factors that determine step height and depth

The building codes provide a range of measurements for the height and width of the step which everyone must comply with. However, the ultimate number will be calculated, within that range, of course, considering the host of factors.

Before installation, the premeditation should be performed in consultation with the following factors.

Height from the floor to ceiling:

Depending on the wall length of the house, the staircase size will be determined. If the gap between is 8 feet, the total number of steps will be 13-15.

If the length rises to 9 feet or 10, the number of steps will rise simultaneously. Dividing the wall length from the total number of stairs, you will find out the exact height of each step.

Distance of stair run:

Stairway or stair run denotes the total traveling distance from the ascending point to descending or vice versa horizontally.

It will determine the starting point of the staircase from the bottom. If the bottom space is congested, the height will be higher. And if you can manage a wider point, the height will be lower, but more flights.

Headroom:

Headroom defines the smallest distance from the steps of the staircase to the ceiling. This is a grave concern area since around here you will have the least void of a room.

For the safety measure, the lower part of the ceiling is cut off. Usually, the first step is cut off for optimum safety.

User of the staircase:

Depending on the people and pets residing in the house and using the steps on a daily basis, the height, and depth should be calculated.

As the range determined by IRC allows some variations, the exact number can go up or down in consideration of senior citizens, children, pets, and injuries.

How to keep your stair steps up to code?

IRC, IBC, local codes_ lots of codes deal with the prescribed requirements for the height and depth of the steps. To ensure that you did not breach any of the rules and regulations, you have to be aware of the rules regarding steps.

Let’s see how you can keep the stair steps up to code.

Ensure the height of steps stays within range:

The IRC declares 7 ¾ inches as the maximum height of the step whereas, the IBC claims it to be 7 inches for commercial space.

Also, the minimum level should not stoop lower than 4 inches. Keep the range in mind when you calculate the stair riser height.

Check the tread depth requirement:

With nosing, the mandated depth is 10 inches minimum. Without nosing, the number goes up to 11 inches. The nosing should be from 3/4 inch to 1 ½ inch after the riser. The gap of the nosing projections can’t exceed 3/8 inches.

Minimum width requirement should be fulfilled:

According to IRC, the minimum width must be 36 inches at least, excluding the width of handrails. No codes have traveled the area of the maximum width of any stairs, so you have the liberty to explore and settle the matter yourself.

Headroom calculation:

As the name suggests, headroom means the vertical distance from the end of the stair tread to the ceiling. The open space must be 6 feet 8 inches tall minimum, so the heap is protected every time you take the stairs.

Final Thoughts:

The building codes prescribe the requirements for height, depth, and width of steps. For the residential space, the maximum stair riser is 7 3/4 inches and minimum 4 inches. Whereas for commercial space the number is 7 inches. The required depth is 10 or 11 inches minimum depending on the nosing.