Thursday, 20 April 2017
I'm thinking of the individual spaces within a bookcase here - the height between shelves, the depth from front to back and the width between uprights.
Small books: some paperbacks measure only about 180mm high (A Format books: 178mm, Penguin 181mm), so a shelf height of just 200mm (about 8") might be considered adequate in extreme cases.
Minimum depth 152mm (6") but more usually about190mm (7½").
Medium sized books: (B Format 198mm, Demy 216mm, A5 210mm, Royal 234mm) In practice there's a variety of book sizes on most shelves and I suggest that a shelf height of less than 255mm (10") can look a bit cramped.
For most books I recommend a shelf height of between 260mm (10¼") and 305mm (12").
Depth between 240mm (9½") and 305mm (12").
Large books: I have several ("coffee table") books which are around 380mm (15") from top to bottom. In most cases you wouldn't need shelf space high enough for these, as they can just as well lie horizontally.
Records: I would allow at least 330mm (13") to allow for the generous size of some box sets. Depth also 330mm (13").
CDs: I suggest a minimum height of 135mm (5¼") and it's useful to install a backstop 147mm (5¾") from the front edge to stop the CDs sliding away from your grasp.
Sheet music: most of my sheet music lies flat, and so do quite a few of my music books. The height of the shelf can be quite small - that can help with keeping the music sorted into identifiable sections - from around 155mm (6").
I recommend a depth of 255mm (10") and width of 375mm (14¾").
Ring binders: they need about the same height as records.
Document wallets: height 305mm (12") depth 380mm (15") width no more than 500mm (19¾").
Every instance is also dependant on the space available and how the bookcase would look in the room. You might want to leave spaces for windows, ornaments, displays, musical instruments or box files...
Width: this depends on the size of the available space, the appearance of the bookcase and the strength of the material. Wooden shelves can in theory span 750mm to 1000mm (about 30" to 40") but this seldom looks right, as the broad width tends to conflict with the vertical emphasis of the books themselves. With 18mm mdf (which is smoother than wood and not given to warping) I would suggest that the maximum span for a book shelf would be 510mm (20") to avoid sag. The span can be increased with thicker material (e.g. 25mm mdf) or gluing pieces together in an mdf sandwich.