THE SECOND-floor bedroom wing of a house we were remodeling conveniently divided into two bedrooms for a teen-age boy and girl. Since the roof was steep and the attic ample, we decided to make lofts for each bedroom. As illustrated, the boy's room (the girl's room is identical) has a skylight directly above the access ladder to the loft. This skylight performs in several ways:

*As an additional light source to the loft and bedroom below,

*As a summer air vent which can be closed in winter so heat rising from the floor below will warm the loft;

*As a lookout to neighboring houses.

The changes to the space were minimal. The roof was raised two feet to accommodate the skylight lookout. We added plywood flooring, a wood ladder and railing around the side of the loft open to the bedroom below. Fortunately, an existing window at the end wall was available to supplement the skylight for light and ventilation.

Since the loft and skylight were constructed as part of the overall house renovation, the additional construction for this work was small. However, the lookout would be suitable to many existing houses as well.

We have estimated that the work could be completed by an experienced builder in a couple of weeks. Better consult such a builder or an architect before attempting the work yourself because of the structural changes involved.

The selection of materials is important, particularly for the skylight. A reasonably sized unit will be needed: one which is operable, consists of two layers of plexiglass and is weathertight. Given the choices, be sure the dome you select is available. WHAT IT WILL COST

Discounting your time and builders' labor, the materials alone are approximately as follows:

*Roof skylight, flashing and shingle patching . . . . . . .$375

*Floor framing around opening and railing, ceiing insulation, plywood floor, wallboard and finish trim . . . . . . .$200

*Ladder, paint and carpet . . . . . . .$150

GRAND TOTAL . . . . . . .$725