In a wallet.
For use with the BRE report: Site layout planning for daylight and sunlight :a guide to good practice / by P.J. Littlefair.
Title from cover.
Sun-on-ground indicators : a set of transparent indicators to predict the availability of sunlight on the ground at the equinox (21 March). ISBN 0851255078. Published by Building Research Establishment in 1991. Publication and catalogue information, links to buy online and reader comments.