Castle Loft Bed with Stairs and Slide

Rather than cutting every piece from a master list up front, work in sections: build the front towers first, then the slide, then the stairs, cutting plywood as you go. Each section stands on its own — and is heavy — before being joined to the others.

Connect the tower sides to the tower fronts (the narrow and wide panels) with pocket holes and 1-1/4" screws, keeping the sides attached to the backs of the fronts so the towers land at their full widths. Cut the door in the front-middle section — about 22" wide by 38" high, drawn with pencil first and cut with a jigsaw — then connect the middle section to the two towers, flush at the backs. Cut the window-seat openings in the wider tower, each about 4-1/2" x 7-1/2" with 1" between them, rounded at the top.

Add the narrow front-right filler section to the end of the front assembly so the whole front is long enough for a twin mattress.

Take the two slide sides and the slide back and attach the slide platform support to one side, about 12-1/4" from the back — do this before joining all three panels, since the space gets tight to work in afterward. Attach the 1x2 slide-rail supports along the layout line running from the front of the platform support to the front of the bottom support, on each side, then join all three panels together.

Optionally cut a curved profile into the outer and inner slide walls for an open look, drawn by hand and cut with a jigsaw. Cut closet openings underneath the slide the same way — this reclaims the otherwise wasted space below.

Attach the slide platform to its supports. Cut the slide panel — melamine-faced plywood if you can get it, since the slick surface makes a real difference — trimming the top at an angle by trial fit until it sits snugly against the platform. Countersink screws up from underneath into the supports to fasten the slide down.

Attach the stair sides to the stair back the same way as the slide box. Attach the 1x2 step supports to both sides at the top and bottom of each step location, and attach the top, middle, and bottom stair-support panels at this stage as well.

Attach the treads to the tops of their supports. Optionally trim the outer stair edge for a cleaner look, finishing the cut edge with a 1x2 on its side as a rail. Cut closet openings underneath the stairs, same as under the slide.

Attach the front, slide, and stair sections together. Build the railings from 1x4 top and bottom rails with 1x2 vertical slats spaced about 3" apart, cutting each run to its own measured length — measure the actual gaps rather than trusting the plan's numbers exactly, since small variations add up. Bolt the back railing into wall studs for real load support, and add L-brackets from the inner stair and slide railings down to the under-bed slats, since these two runs see the most side-load from climbing.

Attach the 2x2 mattress support rails to the front of the back railing and the inside front of the bed, flush with the bottom of the railings, using 2" screws and glue. Screw down the mattress support slats about 2-1/2" apart across the rails for real weight-bearing support.

Attach the tower cap trim pieces to the outside tops of the towers, about 1-3/4" proud of the tower tops. Cut the 1/8" plywood parapet strips with a castle-notch pattern along one edge, sized to fit behind the cap trim, and nail them in place.

Apply edge banding or trim moulding to raw plywood edges. Paint or stain the whole bed. Add any decorative touches — a shaped plywood peak over one tower, a shaped front panel above the railings, painted base moulding, and wall decals if desired.