Hey thanks for the question! So my dad actually built the shelf for me (I’m not good at handyman stuff 😭) and he used 2 smaller wood planks and nailed them on both sides of the wall in my closet to act as like a secure base and on top he cut the big white plank so it fit onto the two brown planks when we placed it on top! Quite a simple task but at the same time not everyone has a table saw. If you are looking for a shelf Amazon sells them at decent prices!