Home Design: How Wide Should a Staircase Be?

When remodeling or replacing your staircase, you will inevitably be faced with wondering how wide your staircase needs to be. 

Your staircase is subject to building regulations.

It is important to note that your staircase’s height, width, tread depth and riser height are subject to building regulations and it is always a good idea to check the before proceeding. 

Stair width.

Building regulations state that the width of your individual stairs should be at least 3 feet or wider. As long as the 3 foot width is met, you can expand as much as you like. 

The entire width of your staircase needs to reach a minimum of 36 inches wide. This measurement refers to the distance between both sides of the staircase and does not include the handrails. 

This is an important factor to get right because staircases that are too narrow can pose dangers to those using the stairs while carrying a load as this can result in a fall. If there is a fire in your home, the stairs have to be wide enough to accommodate people trying to escape the building. 

Different staircase types have different requirements.

Depending on the style of staircase you choose, it will be subject to a different set of code requirements. 

Riser height. 

Staircase risers (the back and vertical portion of your step) need to be a maximum of 7 3/4 inches high. This regulation is in place to prevent your stairs from being too high to climb or too deep when going down. 

If your staircase has open risers (gaps), the space between steps must be a little less than 4 inches high. 

Tread depth. 

Tread depth is subject to a minimum depth of between 10 and 11 inches. If your steps consist of nosings that overlap the risers beneath them, the minimum measurement is 10 inches. However, if you don’t have nosings and your stairs have solid risers, the minimum measurement is 11 inches. 

Headroom. 

Staircases must also follow certain regulations in terms of headroom. This means that at any point on your staircase, there should be a vertical space distance of at least 6 feet and 8 inches which is measured from the top of the tread to the bottom of your ceiling. Failure to adhere to these measurements could result in stair users not having enough vertical room in which to climb the stairs, leaving them at risk for head injuries. 

Landings. 

It is the law that each staircase must have a top and bottom landing. The landing’s width must be no wider than the actual staircase and the minimum depth should be at least 36 inches. 

Finally, compliance with The Americans with Disabilities Act is always a strong recommendation when building a new staircase or modifying an existing one. This ensures that staircases are accessible to those with sensory or motion impairments and that there should be at least 2 handrails. It is suggested to have a rail-to-tread width of at least 27 inches.