The little guy lives in a closet. We call it Mark's room, but that is a euphemism designed to keep him from whining about a living space so small even a five-year-old has trouble turning around when a dresser drawer is open.

To make things worse, the room is right under the peak of the roof, so two walls slant in at a 45-degree angle. Only in the center is there a narrow swath of eight-foot ceiling.

Being a closet to begin with, it had no closet, and he is getting to the age where some of his clothes need hanging up -- although not, of course, to the age where he would actually hang them up.

The hallway leading to his room suffers from the same slanting wall/ceiling line --what do you call those headbangers, anyway? -- on one side. Plan A was to simply build a closet with double sliding doors in the wasted space beneath the overhang. I had been thinking about doing it ever since we bought the house.

It was not until I was hauling in the 2X4s and plasterboard that it occurred to me to lay off the outlines of the partition on the floor and walk through the imaginary passageway it left. I discovered Plan A would box Mark in like a fly in a bottle. To get to his closet he would have to come out of his room and close the door; and if he came out with the normal vigor of a pre-schooler the room door would slam into the closet doors hard enough to knock them off their tracks.

Having always failed the spatial-relations parts in IQ tests, I usually find these things out halfway through a job, when the floor and ceiling plates have been nailed and the studs set.

With the problem perceived, the solution was simple. I built a wall across the hall six feet outside his door, which was removed and mounted in the new doorway. This avoided the bottleneck, lengthened the closet to six feet and put it inside his room, created a place for shelves, and increased Mark's private space by almost half. Not the least of the virtues of Plan B was that it saved me from having to undertake my first outside (convex) corner in plasterboard, a building material I despise.

The only new problem Plan B introduced was how to make the transition from the slanted wall to the upright section. The solution, which also created a solid horizontal beam to hang the sliding doors from, was to make a diagonal cut lengthwise through a 4X4 as deep as the slanted-wall section was wide. The cut surface nailed flat against the slanted section, and the uncut part of the beam was anchored to a stud in the new wall, making both more rigid.

(Those who build book willa chuckle out of the gross over-building illustrated in the photos, but living in a series of papier-mache apartments left me with a thing about walls that ripple like stage sets when a door is slammed. My doors, framed in butted 4X4s, close with the solid "thunk" of a walk-in safe.)

The new wall (since painted) looks as if it has been there all along, which is the nicest thing you can say about amateur home remodeling. The total cost, using first-grade lumber and including the closet doors (bought from a salvage dealer for $6 each), hardware and paint, was less than $100.