Gross External Area

Method of measurement from the Valuation Office Agency, United Kingdom. GEA includes perimeter wall thickness' and external projections, areas occupied by internal walls (whether structural or not) and partitions, columns, piers, chimney breasts, stairwells, lift/wells, lift rooms, plant rooms, tank rooms, fuel stores, whether or not above roof level and open-sided covered areas (should be stated separately). GEA excludes open balconies, open fire escapes, open sided covered ways, open vehicle parking areas, terraces and the like, minor canopies, any area with a headroom of less than 1.5 metres (except under stairways) and any area under the control of service or other external authorities.