This entry outline the steps I am following in order to create a 1:5000 scale site plan, in this case for site no. 4 near Clipstone in West Nottinghamshire.
Step 1 is to identify the co-ordinates of the OS 1km squares the site is located in from 'Where's the path?' - see screenshot 1: http://www.flickr.com/photos/archiblog/8432645504/sizes/l/in/photostream/
Step 2 is to transfer that information to OpenStreetMap in order to determine the 'Area to Export' and then choose the SVG option - see screenshot 2: http://www.flickr.com/photos/archiblog/8431574443/sizes/l/in/photostream/
Step 3 is to open the exported file (map.svg) in Inkscape - see screenshot 3: http://www.flickr.com/photos/archiblog/8431620327/sizes/l/in/photostream/
Step 4 is to crop 'map.svg' - see this tutorial: http://inkscapetutorials.wordpress.com/2011/02/22/inkscape-faq-how-do-i-crop-in-inkscape/
Step 5 is to ungroup all the objects in (a copy of) 'map.svg' and then, using 'map.svg' as the source file, transfer each object to its own (sub)layer in a new destination file - see screenshots 4 and 5: http://www.flickr.com/photos/archiblog/8435208144/sizes/l/in/photostream/ http://www.flickr.com/photos/archiblog/8435207840/sizes/l/in/photostream/
The above steps are intended as a reminder to me as much as a possible help to anyone else. I hope that it will be possible to automate some of this process, perhaps using Quantum GIS etc. as advised by SK53 in a comment on my post dated 20 January 2013 at 14:32.