Firstly decide on the length that you wish the bench to be. Measure 6 boards at this length and mark a line across the width of the board using a carpenter’s square. This will ensure a square cut/right angle/90 degrees.
Using a circular saw cut the boards. These will be the front, back, and lid.
Measure out and cut 4 boards equal to “the width of 2 boards less the thickness of 2 boards”. This should be approximately 37cm. These will make up the end panels and will sit inside the front and back panels.
When all boards are cut, sand them all over.
Cut 4 lengths of the smaller gauge timber (here we have used 2x1, if your bench is to go outside then use a treated timber of similar size) to 40cm.
Use these to join the smaller boards together to make up the end panels. When screwing nearer the end of the timber make sure you drill a pilot hole first.
Fix the longer boards to the end panels, screwing through into the 2x1. Drill pilot holes first then fix together with screws minimum size 4x70mm. Repeat on all 4 boards and both end panels so that you now have a 4-sided box.
To make the top, cut 2 lengths of 2x1 to 36cm, making sure this is less than the INTERIOR width of the box. Fix the remaining 2 longer boards together with these lengths. Use 4 x 40s. Position the 2x1 evenly so that when the lid is in position they sit inside the sides of the box.
Position the lid on top of the box. Fix hinges to the back of edge of the lid. They can be screwed directly on to the face. Use 4 x 30s.
Step 10. Stain/paint/oil or varnish to finish if require.