http://www.legislation.gov.uk/nisi/1979/1709/schedule/1/paragraph/18/2006-01-01Building Regulations (Northern Ireland) Order 1979texttext/xmlenStatute Law Database2017-09-212006-01-01SCHEDULESSCHEDULE 1MATTERS IN REGARD TO WHICH BUILDING REGULATIONS MAY BE MADE18Open space about buildings and the natural lighting and ventilation of buildings.