The plan grew out of a typical parental dilemma: The girl had a large bright bedroom with a connecting play space in the finished attic of the garage. The younger boy's room was half the size of his sister's and he felt cheated.

The parents' first solution to the boy's bruised ego was to build a new extension over a first-floor den as a bedroom. It was a feasible plan, but very expensive. So we studied the boy's room for an alternative approach.

The room was adjacent to the stair to the attic -- one actually entered the attic through the boy's bedroom. The better solution: Open the boy's room to the attic and create a sleeping loft. Not only was it a feasible plan, it was a lot less costly. Actually, it was a relatively simple idea; you should always explore your existing usable space before adding on.

I would like to think that following that basic principle (there are others) is worth an architect's problem-solving time. It is not that the average homeowner can't come up with the same or a better idea and save a professional fee. An experienced designer can usually come up with ideas more quickly and can think through the implications of a prospective plan.

Consider the follow-through aspects of the loft bedroom we proposed:

* How can we introduce natural light? Skylights or roof windows would work.

* How can we provide proper ventilation? Operable skylights will help; a ceiling fan would be even better. A window air conditioner located on the end wall of the attic could do the whole job.

* How will we heat the room? This poses fewer problems because heat rises. A baseboard electric unit will supplement this heat.

* In removing the ceiling, what structural problems arise? Because the span is small (10 feet) all that is needed is to reinforce the ridge beam between end walls. The hall wall, adjacent the bedroom, supports the loft.

Of course, many other questions must be answered (for example, what finish materials to use) and lots of choices made (such as how to design the loft railing, what lighting to use, etc.). Still, the remaining decisions are refinements on the basic ideas and will evolve as construction proceeds.