Assessing educational seating

Explaining how chairs are tested in accordance with EN 1729.

When supplying seating (and tables) to the education sector, there are two key standards with which to demonstrate compliance that will often be included as part of the contractual agreement. These are i) EN 1729-1:2015 – ‘Furniture – Chairs and tables for educational institutions. Functional dimensions’, and ii) EN 1729-2:2012+A1:2015 – ‘Furniture – Chairs and tables for educational institutions. Safety requirements and test methods’.

Part 1 of EN 1729 is based on the principle that seating should be designed to promote good posture. The previous (2006) and latest revisions include a set of specified dimensions (and angles) for such characteristics as seat height, seat width, position of the lumbar region, height of arm rests, angle between seat and back, and more. These are either given as minimums, maximums or a range for each characteristic. Once a set of dimensions has been measured, the chair can be classified between size marks ‘0’ and ‘7’, with 0 being the smallest (see table 1). These size marks are indicated by a colour-coded label or some coloured component on the furniture. The smallest individual dimension (or angle) found dictates the size classification, even if all the other dimensions found comply with larger sizes.

Table 1: Size mark guide
Size mark	Colour code	Indication of age range
0	White	Less than 4 years
1	Orange	3 to 4 years
2	Violet	4 to 5 years
3	Yellow	6 to 7 years
4	Red	8 to 10 years
5	Green	11 to 13 years
6	Blue	14 to 18 years
7	Brown	18 years plus

Part 2 of the standard is used to ensure that the seating meets a set of minimum requirements for safety, stability, strength and durability. The quantity, severity and position of the various test loads and cycles depend on the size mark determined from the measurement results of part 1.

Both standards were first published in 2001. However, the latest revisions (dated 2015) have seen the implementation of some significant changes, particularly in part 1.

Significant changes

Part 1 – The most important change is how the seat height, seat angles, seat depth, armrest height and distance from backrest to the front edge of the armrest are measured. For size marks 3 to 7, a special jig called the ‘school chair measuring device’ (SCMD) is now used instead of basic measuring tools. This consists of a base plate which is positioned on the seat surface, and a vertical arm which is positioned against the back rest. These are joined to each other with a pivot and slide mechanism. Both the base plate and the vertical arm have various adjustable pins that are used to correctly position them on a particular size and shape of chair. The SCMD is positioned according to the form and position of the lumbar region of the back rest (described in the standard as point ‘S’ or the ‘most forward point of the back rest’) and the highest point of the seat surface. Measurements are taken and correct form is assessed from the adjustable pin positions, the angles of the base plate and vertical arm, and other specific protruding elements.

In terms of the actual dimensional requirements, the most significant change is how the width of the back rest is measured. Previously, it was measured at the maximum width, whereas the 2015 version requires it to be measured between the ends of the horizontal line that passes through point ‘S’.

Part 2 – The main change in part 2 is the method used for the strength and durability tests. It continues to be EN 1728 – ‘Domestic furniture – Seating – Test methods for the determination of strength and durability’, but has been updated to the 2012 revision from the 2000 revision. This change is not significant in itself, as the changes to EN 1728:2012 are relatively minor (such as the use of 200 mm diameter load pads instead of 100 mm for the seat front edge durability test). Other changes to part 2 include additional consideration for swivelling chairs and chairs with arm rests, the clarification of seat and back loading points, and amendments to some of the loads and forces.

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