Straight Run

• Straight run stairs are easy to construct.Jupiterimages/Creatas/Getty Images
  
  Straight run stairs are the type used most in new home construction. These stairs have no turns and are therefore simpler to construct. Prices vary with materials used. Usually, the main stairs are made of hardwoods such as oak, birch or maple while service stairs to a basement or garage are made of pine or fir. Stairs that will be carpeted may be constructed of lower grade woods since aesthetics are not as much of an issue.
  
  

L Stairs

• L stairs have defined landings.Hemera Technologies/AbleStock.com/Getty Images
  
  The L stair contains a landing at some point along the steps. This stair type is used when the space required for a straight run is not available. A 90-degree turn is present where the two runs of stairs meet at the landing. Less commomly used in residential construction is the double L stairs that feature two landings and two 90- degree turns. If the landing(s) on L stairs are located near the top or bottom of the stairs, the stairs are classified as "long L."
  
  

U Stairs and Winders

• U stairs denote two flights of parallel steps with a landing located between them. Wide U stairs are far enough apart to have a stairwell between them while narrow U stairs have little or no space between the two, parallel flights. Winder stairs feature "pie-shaped" triangular steps where a landing would normally be placed. The winder is used where space is insufficient for the placement of a landing.
  
  

Spiral Stairs

• Spiral stairs are used when space is limited.Jupiterimages/Photos.com/Getty Images
  
  Where space is severely restricted, a circular or spiral stair is used to join two levels. Spirals are common in small, two-level loft apartments where square footage is an issue. Many spiral stairs are made of welded steel but wood construction is possible. Since all steps are wedge-shaped winders, spiral steps can be more difficult to climb and less accessible for the physically challenged.
  
  

Design Differences

• A staircase may be made with straight boards in a simple box design, or sport a finished miter return on the ends of the open treads for a more polished look. Painted stringers and risers made of cottonwood, combined with stained oak treads, can keep overall costs down. If cost is not an issue, open-look stairs may be constructed completely of a more costly grade of high end oak or other hardwoods.