L-shaped extendable campervan bed

Found this insanely hard to work out the measurements for and design it, simply because I made life hard for myself by making it having to do everything.

Quick info

6ft long (which turns to 7ft when including worktop)

Space for a sliding drawer at the back

120cm wide (when extended)

Can be made L-shape

Slats are 1x3 timber

Frame is 1x2 timber

The whole bed had to be able to extend, easily, yet the design had to have room to fit a slide out draw at the back.
Not only does the bed have to extend, I wanted an l-shape section which is able to pull out on its own, so you have a bit more space when sat inside.
The height had to be high enough to fit a coolbox underneath - however not too high so that your head hits the roof when sat on the bed.
It had to be 6ft long at a minimum, and wide enough to be able to sleep two people, comfortably, yet still leave room to be able to build a decent sized cupboard next to it.
Oh and it had to pretty much be able to butt up to the cupboard at full extension, however the l-shape section needs to not be too close to the cupboard, otherwise you wouldn't have enough leg room.

It took a lot of sketches and measuring to be able to build it sturdy, yet try to minimise the amount of weight of wood.
The bed is around 6ft long, however I built it so that once the foam cushioning is on, the seating will be the same height as the front worktop. This is so when using it as a bed you'll gain around an extra foot of space in length, making it roomy.

The slats slide in-between each other, allowing it to extend, by fixing every other slat to the same length of wood - its easier to look at the pictures. Then, for the L-shape, I just put that section on its own separate length of wood, so you can extend that part separately