I amafraid the best route is always CAD starting with the designers drwings electronically and OS maps electronic if required. Not that user friendly though unless you have a CAD person available on staff/team.

Hi Tessie, If your needs are fairly standard (ie you're wanting to make reasonably simple office / location layout plans) then have a look at Omnigraffle (http://www.omnigroup.com/). It's extremely easy to use. Omni produce some of the most useful and useable software I've ever used, and while Omnigraffle is aimed at producing flowcharts, diagrams and the like, it can also make scale drawings. I think I remember reading that the people at Omni used it themselves when planning moves to new offices. Omnigraffle is one of the reasons I keep a mac around. Other products are available, etc etc. Good luck.

Simply done in Microsoft Word using the shapes and line drawings.