Because reading of music will be involved in this building, we might want to consider this publication by the Education governing board.
Standard Specifications, Layouts and Dimensions:
http://webarchive.nationalarchives.gov.uk/20130401151715/https://www.education.gov.uk/publications/eOrderingDownload/3653_SSLD_lighting_AW%5B4%5D.pdf
posted by Esther Idoko