This project is a result of necessity [I had to get a bed that would fit in limited space, but couldn't find ready-made one]
I've chosen the simplest, fastest [and possible the cheapest] way to make it.
Step 1: Materials and Tools
CLS timber 38x63x2400mm [15 pcs - number depends on the number of railings you want to include]
MDF 18mm 1220 x 2440 [2 pcs - cut to size], keep the off-cuts you will need them
Angle brackets [50 pcs] [Angle Shrinkages Self-Colour 33 x 25 x 1.2mm]
Wood screws 8 x 1 1/2" [250 pcs]
Wood screws 8 x 3" [60 pcs]
Door hinges [2 pcs]
Cordless combi drill
2mm drill bits
Step 2: Legs
Each leg is made from 2 CLS lenghts joined in L-shape using 6pcs 8 x 3" screws.
Short lenghts [marked in YELLOW] are used to create supports for frames - each is attached with 4pcs 8 x 3" screws [2pcs on each side]
Step 3: Frames
Frames are made from CLS lenghts secured with angle brackets on the inside corners.
MDF board is then attached on top of each frame using 8 x 1 1/2" screws.
Step 4: Assembly
Most of the weight is carried by supports attached to legs.
Frames are secured in place using angle brackets screwed to legs and short lenghts of MDF on the outside [this also adds rigidness to structure],
Step 5: Railings and Ladder
Number and height of railings depends on individual circumstances [thickness of mattress, height of bunkbed, etc]. Railings are secured in place using angle brackets, some of which are flattened [inside ones].
I have used salvaged ladder, but you can easily make one from 2 CLS lenghts and some off-cuts using angle brackets [now you know what is my favourite carpentry component :-) ]
Step 6: Appendix
All holes are pre-drilled to avoid splitting the timber [an important precaution].
Measure twice [or even better: thrice] - cut once. If you make bunkbed to fit in a niche you REALLY DON'T want to find out it doesn't fit.
Short MDF off-cuts used to secure frames also prevent the bed from moving sideways [if it is in the niche] - check if they match the thickness of skirting boards
To stop rattling against the walls use small pieces of felt with adhesive on one side - stick it to the above MDF pieces.