1 Good light, both natural and artificial, to assist reading

2 A few comfortable chairs, for the same purpose

3 Sturdy shelving, capable of bearing the weight of books and preferably in unpainted timber

4 Adequate heating: it's hard to read in a cold room, and damp is bad for books. And a real fire is an asset in a library

5 A rich colour palette. Shades of red are always effective

6 Books, lots of them, preferably - but not exclusively - hard cover, definitely not bought by the metre and including titles someone might like to read