BILLY Height extension unit, white, 32x11x14" - IKEA | Libreria billy, Ikea, Librerie billy
IKEA Billy Bookcase - How to add a height extension to a short bookcase with no pre-drilled holes! - YouTube
BILLY Bookcase, birch veneer, 845/8/531/8x11x931/4" - IKEA
BILLY Bookcase, white, 311/2x11x931/4" - IKEA
Billy Bookcase, Easy to Assemble – Between Naps on the Porch
BILLY Bookcase with height extension unit birch veneer, white - IKEAPEDIA
Why would there be an extension option for the tall BILLY but not the short one? I bought the extension in the clearance section, already assembled, so no hardware came with it.
Step 1- Beginning of Construction – The Ikea Billy Project