Ok, let me start with some context. Home improvement, renovations and "Do it yourself" projects are BIG, in fact, they have entire channels and stores devoted to this stuff (HGTV/DIY Network/Michaels Crafts/Lowes/Home Depot). What if we had this concept in the sims 4?
We already have the craft table to make furniture but having props like stud version of a wall, paint cans, versions of flooring with paint splatters, and even the concept of painting walls (you could re-use the animation from City Living with wall tagging). Home improvement could become a skill alongside handiness. These props and gameplay features would greatly enhance storytelling for many simmers (think of the all "build" videos that people have on YouTube - I'm looking at Deligracy and SimSupply).