Adapting Enzo Mari Sedia 1 chair to American lumber standards

Enzo Mari Sedia chair plans adapted to
American lumber standards.
Measurements in centimeters.

When Enzo Mari published the book 'Autoprogettazione', he wanted to publish furniture designs that anyone could build at home. For that reason he used measurements in all his designs based on European lumber size standards.

For example, the 'tavolette' he used for the Sedia 1 chair  were of two kinds: 20 x 2,5 cms for the seat and the back rest; and 5 x 2,5 cms for the legs and the structure of the back rest.

If you try to build this chair in the US you will have a very hard time. Mainly because you won't find this lumber sizes at any home improvement store.

To begin with, American lumber has its own standards and they are obviously based in inches. But that is just the start because it gets more complicated than that when planning to build your own chair. Even when you buy a 1 x 8 board, that doesn't mean you are going to get a 1" x 8 ".  No, these are 'nominal' measures.  The actual measures are going to be 0.75" x 7.25".

All the conversion from centimeters to inches and the additional adjustments from nominal to actual are probably enough to discourage anyone to attempt to build this chair in the US. Which is the opposite that Enzo Mari was trying to accomplish. Since I have gone through this process several times and I have built a handful of prototypes I thought I would contribute to the cause and share the blueprints of the chair I have adapted to American lumber sizes. You can click on the image above to download the high resolution blueprint.

In order to convert the dimensions, the only rule I have followed has been to keep the seat proportions of the chair. The European chair measures 500 mm width x 520 mm depth (proportion 1.04) and the US chair measures 448 mm width x 466 mm depth (proportion 1.04). The US seat is obviously less wide (52 mm) and less deep (54mm) but that is mainly because the width of the 1 x 8 boards on the seat (pieces A) conditions the width and all the other measures and proportions of the chair.

If you decide to build this chair on pine wood like the original you will need to buy: 2 pieces of 1 x 2 x 6 board ($2.98 each) and 2 pieces of 1 x 8 x 4 board ($9.74 each). From these boards you will cut the 13 wooden pieces required to build the chair (click on blueprint for exact dimensions of the pieces):

The total cost (assuming you already have the rest of the tools needed: nails and saw) should be around $26 per chair in materials. Compare this with the Sedia 1 pre-built chair kit sold by Artek that goes for €265 (~$360). Timewise, you can assemble the chair in an hour from the moment you have cut all the pieces.


Learn more about Enzo Mari's 'Autoprogettazione' and Sedia 1 chair:

• [video] Building instructions for Sedia 1 chair by Enzo Mari
• [video] Enzo Mari for Artek: Homage to Autoprogettazione