The desk is made of 2 Ikea PS lockers and one very long MDF board. We had one made with a length of 3,6 meters by 40,5 cm. Paint the board any colour you like and place it over the lockers. If the space between the lockers is very wide, it is best to support the plate with some sort of lath to avoid bending.
We have also created a cat flap in one of the lockers and now use it as a cat toilet. A small litter box fits inside the locker perfectly.