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Understanding the British and European standard for school furniture

BS EN 1729 Parts 1 & 2

Understanding Size Marks

When choosing chairs for your classroom, it’s important to select the right size mark to ensure that children can sit comfortably, safely, and in good posture throughout the day.

Size marks are part of the British and European Standard for school furniture (BS EN 1729 Parts 1 & 2), which sets out precise measurements for seat height and table height, based on children’s ages and heights.


These standards were created to:

  • Support healthy posture and spinal alignment
  • Prevent strain and discomfort during learning
  • Ensure safety and stability across all classroom furniture
  • Maintain consistency across schools and suppliers


What BS EN 1729 Parts 1 & 2 mean:

  • Part 1: Functional Dimensions
    Defines the recommended seat and table heights for children of different ages, ensuring ergonomic comfort and proper sitting posture.
  • Part 2: Safety and Strength Requirements
    Specifies safety, durability, and stability tests to make sure each chair is strong, sturdy, and fit for a classroom environment.


Together, these standards mean that every chair and table sold under a size mark has been carefully designed and tested to meet the needs of children in education settings.

How Size Marks Work

Each size mark corresponds to a specific seat height and approximate child height range. The size mark on the chairs is then paired with the size mark on the tables to ensure they are the right size for each year group.


Size mark 3 chairs pair with size mark 3 tables
Size mark 4 chairs pair with size mark 4 tables
Size mark 5 chairs pair with size mark 5 tables
Size mark 6 chairs pair with size mark 6 tables


Note: Both size marks 4 and 5 can be used for year 6. We would recommend size mark 6 for those with taller children

Our Approach

Our therapeutic classroom chairs and tables have been approved to BS EN 1729 standards, but with one key difference, we have re-defined what classroom furniture looks like. 

Our chairs support healthy posture and alignment but replaces hard plastic designs with soft, supportive, upholstered seating that helps children feel calm, safe, and ready to learn.

Our furniture is durable and meets the size marks but are made to reflect the warmth, safe environment of a home and allow for flexible seating options.

Our furniture is designed to meet the needs of a classroom but also the needs of the children. It is underpinned by neuroscience, childhood trauma and attachment theory and is inclusive.

We believe that ergonomics and emotional wellbeing go hand in hand. Choosing the correct size marked furniture and knowing it is BS EN 1729 Parts 1 & 2 approved means you can create a truly therapeutic, comfortable classroom where every child can thrive.

Look for the seal on our products

You will find this seal next to the tables and chairs we sell that have been approved to both standards and come in size marks.

Remember to pair your furniture and chairs with the correct size marks.

If you are not purchasing both tables and chairs, don't worry, our chairs will fit your existing school tables in the matching size mark and vice versa!

Keep an eye on out site for new lines. We will be adding new collections and approved furniture as we evolve.

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