I've spent most of the weekend working on my RoomPlan software. It's not finished yet, but you can download a copy of what I've done so far if you like. Only 15k, but it does require the .NET Framework v1.1 (available from the Windows Update site). It will basically work for any room/furniture, although you need to hack the XML file manually for the time being, until I sort out a proper front end editor for it.
So, now that I know where my furniture's going, I can confirm the location of all the new sockets with the builders (who will start rewiring the flat tomorrow). That's basically why I've been doing that rather than project stuff, although I think the techniques I've been learning to do this will come in useful on the project too (and at my job, for that matter).