What are Standard Stair Sizes? Code Requirements for Tread Depth, Riser Height and More

Here is a summary of standard stair sizes and dimensions:

- Tread Depth: Most codes require a minimum of 11 inches of tread depth. Common residential tread depths range from 11 to 12 inches.

- Rise Height: The maximum rise allowed by code is 7.75 inches. Common heights are 7 to 7.5 inches. 

- Gooseneck: The distance between the stair nosings at a 180 degree turn is typically 36-42 inches.

- Width: Minimum width for a residential stair is 36 inches between handrails. Wider stairs are more comfortable for traffic flow.

- Headroom: Minimum clear height is 6 feet 8 inches measured from the stair nosings to the lowest projection above, like a ceiling.

- Overrun: The stair should extend past the floor above by at least 11 inches but no more than 12 inches for safety. 

- Winders: The smallest tread on a winder stair should be at least 6 inches wide. The largest no more than 12 inches.

- Landing size: Minimum size for a landing is 36x36 inches. Standard is larger at 48x48 or 72x72 inches.

- Handrail height: Code requires handrails to be placed 34-38 inches above tread nosings. 

Let me know if you need any other stair building specifications or have additional questions! Proper dimensions are important for code compliance and usability.