When a designer designs a chair it needs to meet the user needs. Even though a chair may be functional and attractive, it may not be the right size for the user. Body measurements and other variables need to be considered before the chair can be designed Theses considerations are called the human factors that affect the overall design. Designers also try to design chairs to be ergonomically correct.

Here are some considerations that should be addressed when you designing a chair. As a designer, you should always try to answer the following questions.

Safety of the Product.

• Is the chair safe to sit in without collapsing?
• How far can people reach back safely without the chair tipping over?
• Can someone get cut from a sharp edge on the chair?
  

The Human Element

• How does it feel when you sit in the chair for a long period of time?
• Does the chair conform to your back, legs, neck and feet?
• Could you sit in this chair for an extended period of time?
• Does your chair allow for sufficient lines of sight for the average person or the handicap?
• Have you accounted for the physical size of the the user?
• Armrests aid people when they rise out of a chair and they also support the arm while working or relaxing in a chair.

The Audience

• Does your chair have sufficient enough space to accomadate the elderly and disable?
• Does your chair allow for sufficient lines of sight for the average person or the handicap?
• Have you accounted for the physical size of the the user?
  
  
  By altering the height, width and depth of any chair it can affect the purpose of the chair. If a design is altered too much it can also affect the resale value of the chair. Knowing established standard dimensioning sizes can make it easier for designers to create new and exciting chairs. Standard dimensions are dimensions based on the average size of a child or adult.

  Counter Top Height :
  The average height of a countertop is 36 inches above the floor.
  Machines :
  Machines can vary from a variety of heights. Some examples can range
  from 33 inches to 46 inches.
  Walking Spaces:
  Space is needed to move people around furniture and objects. Wheel chairs for example need a 5 foot minimum turning radius.

  Tables: There is a close relationship between tables and chairs. Table heights vary with different purposes. Desk and dinning tables are approximately 29-30 inches tall.

The Purpose of a Chair:

Chairs should be designed for comfort and convenience. The two general classifications for chairs are straight and lounge.

Straight chairs position the person upright for dining or working.

Lounge chairs recline and are used for relaxing.

Standard chair dimensions describe the heights to accommodate the average male and female. Standard seat height is 17 inches although it may be reduce to 15 inches if it is designed for a smaller person and can increase up to 18 inches for a taller person. Seat depth can also vary 16-20 inches but any angle over 30 degrees must be supported by a headrest. Armrests aid people when they rise out of a chair and they also support the arm while working or relaxing in a chair.

Next