Built-in wardrobes are good inexpensive renovations that get you lots of additional storage space. They're pretty simple to build, and make a good project for someone wanting to develop their DIY skills. You'll get experience in how to frame a wall, how to put up drywall, how to plaster, and how to install a set of sliding doors. The whole project costs about $150, assuming you've got the required tools already. If you don't, what better excuse?
The built-in wardrobe described here is designed for shoes (a wardshoe?), so it's a bit shallower than the average wardrobe, and it's filled with shelves rather than a clothes rail. However, the construction is pretty much the same as other built-in wardrobes I've made - this is just the only one I thought to document. It took an afternoon to build, then plastering took a week as did painting.
This design is meant for a corner wardrobe of full height, and wide enough to fit a 4' wide set of sliding doors (two 2' wide sliding mirror doors). I'd always hated the sloppy boxing that protruded into this room, and we were always tripping over shoes that were dumped unceremoniously on the floor. A 4' wide wardrobe would cover both problems. All that was needed was two simple frames, which could be screwed to the walls, floor, ceiling and each other. For dimensions, see the sketch.
The room is wired with a light switch on each side. I planned to remove the one that would be hidden in the wardrobe and replace it with a receptacle, so we could add a small heater if needed in the winter months.
Four shelves 400 mm apart, plus the floor, would give us separate footwear storage for each member of the family (5). I also added a half-depth shelf 400 mm higher (above the level of the door) for some additional storage.