This study constructs optimal real estate portfolios using returns from Great Britain (England, Scotland, and Wales) and Ireland (Northern Ireland and the Republic of Ireland). Data from IPD for ten major regional centres are used for office and retail property from 1984 through 2002 (excluding London). In addition, total returns, income only returns, and appreciation only returns are used. The optimal portfolios are dominated largely by property in Belfast and Dublin. When three markets areas of London were included in the optimization, the results remained largely the same with London property entering few of the portfolios and with a low allocation.