What specifications does a computer workspace need to meet?
Working at a computer imposes extra demands on the furniture. What specifications need to be met in this respect?
- Starting point
- Desk chair
- Foot support
- Computer screen
- Document holder
- Working environment
With ideal support, the static load associated with work at a computer can be made less straining. This is why both the office chair and the office table can be adjusted according to the user’s physical measurements. The user should be able to adjust the position while sitting, without the use of tools.
- Specifications for an office chair: NEN 1812 type HAV / HRAV
- The height of the seat should be adjustable: at least 41–53 cm measured from the front of the seat or as adjusted by the user.
- The seat should have an adjustable depth should be adjustable to at least 40–44 cm from the back of the chair to the front of the seat.
- The back should be at least 37 cm high and fitted with a surface for lower back support 22 cm high with a vertical bulge with a radius of between 25 and 30 cm. The part of the back above the lower back support should not come forward and should not obstruct the shoulder blades.
- Short armrests (at least 20 cm between the front of the armrests and the front edge of the seat), with an adjustable height of between 20–30 cm above the seat; adjustable width of 42–50 cm; entirely flat and large (at least 15 cm x 6 cm) sloping slightly forward diagonally.
- Safe construction: gas spring damper, five-pronged base.
- Specifications for a work table: NEN 2449
- Entirely flat, with a light colour, but not with a reflective (shiny) top.
- Working surface at least 120 cm wide and sufficiently deep with respect to the viewing distance to the computer screen.
- The height of the work table should be 74 to 76 cm or a height adjusted for the user.
- The thickness of the top, including the support structure, should be less than 2 cm on the front side.
- Free legroom (at least 65 cm deep and 60 cm wide) and sufficient free room for the feet (at least 80 cm deep).
- Specifications for foot supports: DIN 4556
- If a work table is too high, a foot support may be necessary so that the chair can be adjusted properly and to ensure a healthy work posture.
- The support surface should be around 45 cm wide and 35 cm deep.
- The height of the support surface should be adjustable and be between 5 and 11 cm on the front side (higher for laboratory tables).
- The angle of the slope should be between 5 and 15° or be adjustable.
- The adjustments should be simple to carry out and stay firmly in place.
- The surface area should be non-slip.
- Specifications for computer screens: NEN-ISO 9241
- Brightness of characters must be adjustable
- Adjustable brightness between characters and background (contrast)
- Tiltable, pivoting and with adjustable height
- Preferably darker characters on a lighter background
A good mouse is not thick (4 cm maximum). The thicker the mouse, the more the hand gets bent back. It is precisely the position of the wrist that is so straining. Beyond that, the mouse should have a neutral shape and not have any sharp angles, making it appropriate for both left- and right-handed users. The cord of the mouse should be long enough. An optical mouse equipped with a scroll wheel is recommended.
- Specifications for document holders: NPR 1813
- Can be freely placed on the work surface
- Angle with horizontal surface adjustable between 25° and 75°
- Support surface not smaller than the document itself
- Stable and doesn’t shake
- Specifications for keyboards: ISO 9241-3
- Can be repositioned separately from the monitor and with a cord at least 1 metre long connected to the CPU
- As thin as possible (no thicker than 4 cm)
- The average slope from the front between 5–25°
- Underside should be rough
- Keys not reflective, not too small and preferably in a light colour with the characters on them printed in a darker colour
- Specifications for daylight/artificial light: NEN 3087
- Contrast computer monitor: distant surroundings (at most 1:30)
- Sunblinds that can be operated individually
- Can be used in all circumstances (exterior shades often raise automatically)
- Preferably vertical, a sufficient number of opaque strips (not white, not shiny) in front of the windows
- Specification for daylight/artificial light: NEN 3087
- General lighting 200–500 lux, direct workspace lighting not reflecting on the computer screen
- Specifications for atmospheric conditions: NEN-ISO 7730
- Temperature: summer 25–26°, winter 20–24 degrees
- Air velocity: summer 0.35 m/sec, winter 0.15 m/sec
- Humidity 30–70%, ideally 45%
- Number of people, equipment
- Ventilation: 60 m³/h per person
- Specification for noise level: NEN 1070
- Noise from equipment at most 45 dB if no one is talking at the work station
- Reverberation time: 0.6–0.8 sec